Suppressing negative thoughts may be good for mental health after all

September 20, 2023

Science Daily/University of Cambridge

The commonly-held belief that attempting to suppress negative thoughts is bad for our mental health could be wrong, a new study from scientists at the University of Cambridge suggests.

Researchers at the Medical Research Council (MRC) Cognition and Brain Sciences Unit trained 120 volunteers worldwide to suppress thoughts about negative events that worried them, and found that not only did these become less vivid, but that the participants' mental health also improved.

"We're all familiar with the Freudian idea that if we suppress our feelings or thoughts, then these thoughts remain in our unconscious, influencing our behaviour and wellbeing perniciously," said Professor Michael Anderson.

"The whole point of psychotherapy is to dredge up these thoughts so one can deal with them and rob them of their power. In more recent years, we've been told that suppressing thoughts is intrinsically ineffective and that it actually causes people to think the thought more -- it's the classic idea of 'Don't think about a pink elephant'.

These ideas have become dogma in the clinical treatment realm, said Anderson, with national guidelines talking about thought avoidance as a major maladaptive coping behaviour to be eliminated and overcome in depression, anxiety, PTSD, for example.

When COVID-19 appeared in 2020, like many researchers, Professor Anderson wanted to see how his own research could be used to help people through the pandemic. His interest lay in a brain mechanism known as inhibitory control -- the ability to override our reflexive responses -- and how it might be applied to memory retrieval, and in particular to stopping the retrieval of negative thoughts when confronted with potent reminders to them.

Dr Zulkayda Mamat -- at the time a PhD student in Professor Anderson's lab and at Trinity College, Cambridge -- believed that inhibitory control was critical in overcoming trauma in experiences occurring to herself and many others she has encountered in life. She had wanted to investigate whether this was an innate ability or something that was learnt -- and hence could be taught.

Dr Mamat said: "Because of the pandemic, we were seeing a need in the community to help people cope with surging anxiety. There was already a mental health crisis, a hidden epidemic of mental health problems, and this was getting worse. So with that backdrop, we decided to see if we could help people cope better."

Professor Anderson and Dr Mamat recruited 120 people across 16 countries to test whether it might in fact be possible -- and beneficial -- for people to practice suppressing their fearful thoughts. Their findings are published today in Science Advances.

In the study, each participant was asked to think of a number of scenarios that might plausibly occur in their lives over the next two years -- 20 negative 'fears and worries' that they were afraid might happen, 20 positive 'hopes and dreams', and 36 routine and mundane neutral events. The fears had to be worries of current concern to them, that have repeatedly intruded in their thoughts.

Each event had to be specific to them and something they had vividly imagined occurring. For each scenario, they were to provide a cue word (an obvious reminder that could be used to evoke the event during training) and a key detail (a single word expressing a central event detail). For example:

• Negative -- visiting one's parents at the hospital as a result of COVID-19, with the cue 'Hospital' and the detail 'Breathing'.

• Neutral -- a visit to the opticians, with the cue 'Optician' and the detail 'Cambridge'.

• Positive -- seeing one's sister get married, with the cue 'Wedding' and the detail 'Dress'.

Participants were asked to rate each event on a number of points: vividness, likelihood of occurrence, distance in the future, level of anxiety about the event (or level of joy for positive events), frequency of thought, degree of current concern, long-term impact, and emotional intensity.

Participants also completed questionnaires to assess their mental health, though no one was excluded, allowing the researchers to look at a broad range of participants, including many with serious depression, anxiety, and pandemic-related post-traumatic stress.

Then, over Zoom, Dr Mamat took each participant through the 20-minute training, which involved 12 'No-imagine' and 12 'Imagine' repetitions for events, each day for three days.

For No-imagine trials, participants were given one of their cue words, asked to first acknowledge the event in their mind. Then, while continuing to stare directly at the reminder cue, they were asked to stop thinking about the event -- they should not try to imagine the event itself or use diversionary thoughts to distract themselves, but rather should try to block any images or thoughts that the reminder might evoke. For this part of the trial, one group of participants was given their negative events to suppress and the other given their neutral ones.

For Imagine trials, participants were given a cue word and asked to imagine the event as vividly as possible, thinking what it would be like and imagining how they would feel at the event. For ethical reasons, no participant was given a negative event to imagine, but only positive or neutral ones.

At the end of the third day and again three months later, participants were once again asked to rate each event on vividness, level of anxiety, emotional intensity, etc., and completed questionnaires to assess changes in depression, anxiety, worry, affect, and wellbeing, key facets of mental health.

Dr Mamat said: "It was very clear that those events that participants practiced suppressing were less vivid, less emotionally anxiety-inducing, than the other events and that overall, participants improved in terms of their mental health. But we saw the biggest effect among those participants who were given practice at suppressing fearful, rather than neutral, thoughts."

Following training -- both immediately and after three months -- participants reported that suppressed events were less vivid and less fearful. They also found themselves thinking about these events less.

Suppressing thoughts even improved mental health amongst participants with likely post-traumatic stress disorder. Among participants with post-traumatic stress who suppressed negative thoughts, their negative mental health indices scores fell on average by 16% (compared to a 5% fall for similar participants suppressing neutral events), whereas positive mental health indices scores increased by almost 10% (compared to a 1% fall in the second group).

In general, people with worse mental health symptoms at the outset of the study improved more after suppression training, but only if they suppressed their fears. This finding directly contradicts the notion that suppression is a maladaptive coping process.

Suppressing negative thoughts did not lead to a 'rebound', where a participant recalled these events more vividly. Only one person out of 120 showed higher detail recall for suppressed items post-training, and just six of the 61 participants that suppressed fears reported increased vividness for No-Imagine items post-training, but this was in line with the baseline rate of vividness increases that occurred for events that were not suppressed at all.

"What we found runs counter to the accepted narrative," said Professor Anderson. "Although more work will be needed to confirm the findings, it seems like it is possible and could even be potentially beneficial to actively suppress our fearful thoughts."

Although participants were not asked to continue practising the technique, many of them chose to do so spontaneously. When Dr Mamat contacted the participants after three months, she found that the benefits in terms of reduced levels of depression and negative emotions, continued for all participants, but were most pronounced among those participants who continued to use the technique in their daily lives.

"The follow up was my favourite time of my entire PhD, because every day was just joyful," she said. "I didn't have a single participant who told me 'Oh, I feel bad' or 'This was useless'. I didn't prompt them or ask 'Did you find this helpful?' They were just automatically telling me how helpful they found it."

One participant was so impressed by the technique that she taught her daughter and her own mother how to do it. Another reported how she had moved home just prior to COVID-19 and so felt very isolated during the pandemic.

"She said this study had come exactly at the time she needed it because she was having all these negative thoughts, all these worries and anxiety about the future, and this really, really helped her," said Dr Mamat. "My heart literally just melted, I could feel goosebumps all over me. I said to her 'If everyone else hated this experiment, I would not care because of how much this benefited you!'."

https://www.sciencedaily.com/releases/2023/09/230920152308.htm

Young children do better at school if their dads read and play with them

September 20, 2023

Science Daily/University of Leeds

Fathers can give their children an educational advantage at primary school by reading, drawing and playing with them, according to a newly published report.

Research led by the University of Leeds has found that children do better at primary school if their fathers regularly spend time with them on interactive engagement activities like reading, playing, telling stories, drawing and singing.

Analysing primary school test scores for five- and seven-year-olds, the researchers used a representative sample of nearly 5,000 mother-father households in England from the Millenium Cohort Study -- which collected data on children born 2000-02 as they grew up.

According to the research, dads who regularly drew, played and read with their three-year-olds helped their children do better at school by age five. Dads being involved at age five also helped improve scores in seven-year-olds' Key Stage Assessments.

Dr Helen Norman, Research Fellow at Leeds University Business School, who led the research, said: "Mothers still tend to assume the primary carer role and therefore tend to do the most childcare, but if fathers actively engage in childcare too, it significantly increases the likelihood of children getting better grades in primary school. This is why encouraging and supporting fathers to share childcare with the mother, from an early stage in the child's life, is critical."

Dads' involvement impacted positively on their children's school achievement regardless of the child's gender, ethnicity, age in the school year and household income, according to the report.

There were different effects when mums and dads took part in the same activities -- the data showed that mums had more of an impact on young children's emotional and social behaviours than educational achievement.

The researchers recommend that dads carve out as much time as they can to engage in interactive activities with their children each week. For busy, working dads, even just ten minutes a day could potentially have educational benefits.

They also recommend that schools and early years education providers routinely take both parents' contact details (where possible) and develop strategies to engage fathers -- and that Ofsted take explicit account of father-engagement in inspections.

The research was funded by the Economic and Social Research Council (ESRC) and led by Dr Helen Norman, Research Fellow at Leeds University Business School, in collaboration with co-author Dr Jeremy Davies, Head of Impact and Communications at the Fatherhood Institute, and co-investigators at the University of Manchester.

Dr Jeremy Davies, Head of Impact and Communications at the Fatherhood Institute, who co-authored the report, said: "Our analysis has shown that fathers have an important, direct impact on their children's learning. We should be recognising this and actively finding ways to support dads to play their part, rather than engaging only with mothers, or taking a gender-neutral approach."

Andrew Gwynne MP, Chair of the All-Party Parliamentary Group on Fatherhood, said: "This study shows that even small changes in what fathers do, and in how schools and early years settings engage with parents, can have a lasting impact on children's learning. It's absolutely crucial that fathers aren't treated as an afterthought."

Report: https://business.leeds.ac.uk/downloads/download/314/piece-report

https://www.sciencedaily.com/releases/2023/09/230920111234.htm

Most people rely on parents for material support into adulthood

September 20, 2023

Science Daily/North Carolina State University

A new study finds that only a third of adults in the United States did not rely on their parents for some form of material support between their late teens and early 40s. The study highlights the extent to which parents and adult children rely on each other for financial assistance or a place to live well into the children's adult years, challenging popular conventions and expectations about adulthood.

"This work really challenges the notion that complete independence is a necessary marker of adulthood," says Anna Manzoni, co-author of the study and an associate professor of sociology at North Carolina State University. "Instead, we see a pattern of interdependency that changes over time and appears to be influenced by race and educational background."

For the study, researchers analyzed data on 14,675 U.S. adults who participated in the National Longitudinal Study of Adolescent to Adult Health, focusing on data collected from study participants between the ages of 18 and 43.

Specifically, the researchers looked at various ways in which these adults exchanged financial and residential support with their parents over time, as well as various social and demographic factors -- such as gender, race/ethnicity, and parents' educational background.

"We found that there is no single pathway that most people take regarding independence from their parents," Manzoni says. "Instead, people tend to fall into one of six different categories."

The researchers call these categories "pathways of intergenerational support":

• Complete Independence (comprising 33.44% of survey respondents) refers to children who become financially and residentially independent in their late teens or early 20s and retain that independence;

• Independent with Transitional Support (20.14%) is similar to the "Complete Independence" group, but received some financial support from parents in their 20s or early 30s;

• Gradual Independence (15.07%) refers to children who lived at home into their 20s and received significant financial support, with that support declining very gradually over time;

• High to Low Support (14.63%) refers to children who lived at home into their 20s and received significant financial support, but that support declined rapidly as the children grow older;

• Extended Interdependence (10.22%) refers to children who lived at home for extended periods of time and who not only received financial support from parents but also provided financial support to parents; and

• Boomerang (6.51%) refers to children who moved out in their late teens or early 20s, moved back in with parents in their mid-20s to early 30s, and then moved out again in their 30s or early 40s.

"We also found that these pathways are not evenly distributed across the population," Manzoni says. "For example, Complete Independence is least likely among Black families and most likely among white families, while Extended Interdependence is least likely among White families and most likely among Hispanic families.

"Educational background also appears to be a significant factor. For example, people whose parents completed less than a high school education are far more likely to experience the Extended Interdependence pathway, while people whose parents completed a graduate or professional degree are significantly more likely to experience the Complete Independence pathway.

"Ultimately, the work drives home the extent to which access to resources and structural restraints -- such as access to education -- influence which pathways to independence people have access to. It also makes clear that we need to reevaluate how we think of independence and adulthood, given that only a third of study participants were able to take the Complete Independence pathway that is often presented as being the norm."

https://www.sciencedaily.com/releases/2023/09/230920111144.htm

At which age we are at our happiest?

September 19, 2023

Science Daily/Ruhr-University Bochum

At what age are people at their happiest? This seemingly simple question has been studied extensively over the past decades, but a definitive answer has long been elusive. A research team has now shed light on the question in a comprehensive meta-analytic review. The findings show that the respondents' life satisfaction decreased between the ages of 9 and 16, then increased slightly until the age of 70, and then decreased once again until the age of 96.

An evaluation of over 400 samples shows how subjective well-being develops over the course of a lifespan.

More than 460,000 participants

In their study, the researchers examined trends in subjective well-being over the lifespan based on 443 samples from longitudinal studies with a total of 460,902 participants. "We focused on changes in three central components of subjective well-being," explains Professor Susanne Bücker, who initially worked on the study in Bochum and has since moved to Cologne: "Life satisfaction, positive emotional states and negative emotional states."

The findings show that the life satisfaction decreased between the ages of 9 and 16, then increased slightly until the age of 70, and then decreased once again until the age of 96. Positive emotional states showed a general decline from age 9 to age 94, while negative emotional states fluctuated slightly between ages 9 and 22, then declined until age 60 and then increased once again. The authors identified greater median changes in positive and negative emotional states than in life satisfaction.

Positive trend over a wide period of life

"Overall, the study indicated a positive trend over a wide period of life, if we look at life satisfaction and negative emotional states," as Susanne Bücker sums up the results. The researchers attribute the slight decline in life satisfaction between the ages of 9 and 16 to, for example, changes to the body and to the social life that take place during puberty. Satisfaction rises again from young adulthood onwards. Positive feelings tend to decrease from childhood to late adulthood. In very late adulthood, all components of subjective well-being tended to worsen rather than improve. "This could be related to the fact that in very old people, physical performance decreases, health often deteriorates, and social contacts diminish; not least because their peers pass away," speculates the researcher.

The study highlights the need to consider and promote subjective well-being with its various components across the lifespan, as the authors of the study conclude. Their findings could provide significant guidance for the development of intervention programmes, especially those aimed at maintaining or improving subjective well-being late in life.

https://www.sciencedaily.com/releases/2023/09/230919155016.htm

Job strain combined with high efforts and low reward doubled men's heart disease risk

These psychosocial stressors are each associated with heart disease risk and the combination was especially dangerous to men, finds study in Circulation: Cardiovascular Quality and Outcomes journal

September 19, 2023

Science Daily/American Heart Association

Men who say they have stressful jobs and also feel they exert high efforts for low reward had double the risk of heart disease compared to men free of those stressors, according to new research published today in Circulation: Cardiovascular Quality and Outcomes, a peer-reviewed American Heart Association journal.

"Considering the significant amount of time people spend at work, understanding the relationship between work stressors and cardiovascular health is crucial for public health and workforce well-being," said lead study author Mathilde Lavigne-Robichaud, R.D., M.S., doctoral candidate, Population Health and Optimal Health Practices Research Unit, CHU de Quebec-University Laval Research Center in Quebec, Canada. "Our study highlights the pressing need to proactively address stressful working conditions, to create healthier work environments that benefit employees and employers."

Heart disease is the No. 1 cause of death in the U.S. according to American Heart Association statistics. In 2020, nearly 383,000 Americans died of heart disease.

Research has shown that two psychosocial stressors -- job strain and effort-reward imbalance at work -- may increase heart disease risk. However, few studies have examined the combined effect.

"Job strain refers to work environments where employees face a combination of high job demands and low control over their work. High demands can include a heavy workload, tight deadlines and numerous responsibilities, while low control means the employee has little say in decision-making and how they perform their tasks," Lavigne-Robichaud explained.

"Effort-reward imbalance occurs when employees invest high effort into their work, but they perceive the rewards they receive in return -- such as salary, recognition or job security -- as insufficient or unequal to the effort. For instance, if you're always going above and beyond, but you feel like you're not getting the credit or rewards you deserve, that's called effort-reward imbalance."

The study found:

• Men who said they experienced either job strain or effort-reward imbalance had a 49% increase in risk of heart disease compared to men who didn't report those stressors.

• Men reporting both job strain and effort-reward imbalance were at twice the risk of heart disease compared with men who did not say they were experiencing the combined stressors.

• The impact of psychosocial stress at work on women's heart health was inconclusive.

• In men, the impact of job strain and effort-reward imbalance combined was similar to the magnitude of the impact of obesity on the risk of coronary heart disease.

"Our results suggest that interventions aimed at reducing stressors from the work environment could be particularly effective for men and could also have positive implications for women, as these stress factors are associated with other prevalent health issues such as depression," Lavigne-Robichaud said. "The study's inability to establish a direct link between psychosocial job stressors and coronary heart disease in women signals the need for further investigation into the complex interplay of various stressors and women's heart health."

Interventions might include different approaches, such as providing support resources, promoting work-life balance, enhancing communication and empowering employees to have more control over their work, she said.

"The U.S. workforce is among the most stressed in the world, and these workplace stressors can be as harmful to health as obesity and secondhand smoke," Eduardo J. Sanchez, M.D., M.P.H., FAHA, FAAFP, chief medical officer for prevention at the American Heart Association. "This study adds to the growing body of evidence that the workplace should be prioritized as a vehicle for advancing cardiovascular health for all. The American Heart Association remains committed to and engaged in providing employers with the resources and information they need to actively support the health of their employees and communities through science-backed changes to policy and culture."

Study background and details:

• Researchers studied nearly 6,500 white-collar workers, average age about 45 years old, without heart disease, and followed them for 18 years, from 2000 to 2018.

• They studied health and workplace survey information for 3,118 men and 3,347 women in a wide range of jobs in Quebec. The surveys included employees working in senior management, professional, technical and office workers roles. Education levels ranged from no high school diploma to university degree.

• Researchers measured job strain and effort-reward imbalance with results from proven questionnaires and retrieved heart disease information using established health databases.

One study limitation is that the researchers studied men and women in white-collar jobs primarily in Quebec, Canada, and the results might not fully represent the diversity of the American working population. However, the study findings may be relevant to white-collar workers in the United States and other high-income countries with similar job structures, according to Lavigne-Robichaud.

https://www.sciencedaily.com/releases/2023/09/230919155014.htm

Early treatment of child obesity is effective

September 17, 2023

Science Daily/Karolinska Institutet

The early treatment of obesity in children is effective in both the short and long term, researchers from Karolinska Institutet report in a study published in The International Journal of Obesity.

The researchers followed over 170 young children in Sweden who had received treatment for diagnosed obesity. The children were recruited to the randomised controlled study when they were between four and six years old via children's clinics in Region Stockholm.

The children and their parents were randomly assigned to one of three treatment conditions: standard treatment, parental support group, or parental support group with follow-up telephone support.

The children and parents in the standard treatment group had meetings focusing on diet and exercise with a doctor, paediatrician and/or dietician. The two parental support groups did not involve the children and focused on how the parents could promote healthy lifestyles in the family in a positive way and without conflict.

"Such conversations can centre on how to set boundaries, how to teach children new behaviours and how to communicate with preschools, grandmothers, neighbours and other adults in the children's world," says principal investigator Paulina Nowicka, Associate Professor in Pediatric Science at the Department of Clinical Science, Intervention and Technology, Karolinska Institutet, and professor of Food studies, nutrition and dietetics at Uppsala University.

After attending the parental support groups, half of the participants were then randomly assigned a follow-up phone call.

Studies have been done on children who have been treated for obesity before," says Professor Nowicka. "But most of them have only been followed up after six months or a year, so we have no data on how the children fared over a longer period than that."

The study that she and her colleagues have now published suggest that early obesity treatment has a lasting effect.

"The children in all three groups improved their weight status and saw a reduction in their degree of obesity," she says. "The children whose parents received parental support had the best results, especially so those who also received follow-up phone calls. We also found that more children in this third group showed a clinically relevant improvement of their weight status associated with better metabolic health, by which I mean better levels of blood lipids and glucose."

According to Professor Nowicka, most parents know what kind of food they are to serve their children:

"They usually know this -- but what do you do with a child who loves food and always wants to eat, or one that's always hungry? How do you go about it without making a taboo of food?" she says. "You have to try to build a clear structure at home, one that makes the child know that lunch is on its way and know that they'll be getting supper."

She continues: "But you also need to do things together to strengthen family bonds, like getting the child involved in the cooking, giving the child vegetables if they're hungry and not rewarding them with food. It's also important to make sure that food isn't associated with emotions and achievement."

While obesity is difficult to treat, she explains, the study shows that intensive treatment is safe and efficacious for pre-school children:

"Treating children at that age is much more effective than if you start treating them in their teens," she says. "Some adolescents are looking at possible bariatric surgery and we hope that this can be avoided with earlier treatment."

https://www.sciencedaily.com/releases/2023/09/230917230749.htm

Living in a disadvantaged neighborhood affects food choices, weight gain and the microstructure of the brain

September 15, 2023

Science Daily/University of California - Los Angeles Health Sciences

A new study finds poor quality of available foods, increased intake of calories from foods high in trans-fatty acids, and environments that do not foster physical activity, all prevalent in disadvantaged neighborhoods, disrupt the flexibility of information processing in the brain that is involved in reward, emotion regulation, and cognition.

You are what you eat, according to the adage. But it's not just the body that's impacted. According to research from UCLA David Geffen School of Medicine, living in a disadvantaged neighborhood can affect food choices, weight gain and even the microstructure of the brain.

The study, appearing in Communications Medicine, a Nature journal, finds poor quality of available foods, increased intake of calories from foods high in trans-fatty acids, and environments that do not foster physical activity, all prevalent in disadvantaged neighborhoods, disrupt the flexibility of information processing in the brain that is involved in reward, emotion regulation, and cognition.

Previous research showed that living in a disadvantaged neighborhood can impact brain health, but in this study, researchers did a detailed analysis of the brain's cortex to determine how living in a disadvantaged area can change specific areas of the brain that play different roles.

"We found that neighborhood disadvantage was associated with differences in the fine structure of the cortex of the brain. Some of these differences were linked to higher body mass index and correlated with high intake of the trans-fatty acids found in fried fast food," said Arpana Gupta, PhD, co-Director of the Goodman-Luskin Center and Director of the Neuroimaging Core.

"Our results suggest that regions of the brain involved in reward, emotion, and the acquisition of knowledge and understanding might be affected by aspects of neighborhood disadvantage that contribute to obesity," said Gupta, senior author. "This highlights the importance of addressing dietary quality issues in disadvantaged neighborhoods to protect brain health."

Neighborhood disadvantage is defined by a combination of such factors as low median income, low education level, crowding, and lack of complete plumbing. This study included 92 participants -- 27 men and 65 women -- from the greater Los Angeles area. Demographic and body mass index information was collected, and neighborhood disadvantage was assessed as to its area deprivation index (ADI) using University of Wisconsin School of Medicine's Public Health's Neighborhood Atlas.

Earlier studies have found that people living in disadvantaged neighborhoods are at higher risk of obesity due to the poor quality of available foods, increased intake of calories from foods high in trans-fatty acids, and environments that do not foster physical activity.

In this study, researchers focused on the relationship between ADI and neuroimaging results at four levels of the brain cortex to investigate in more refined detail the connections between neighborhood disadvantage and brain structure. Participants underwent two types of MRI scans that, when analyzed in combination, provide insights into brain structure, signaling and function.

"Different populations of cells exist in different layers of the cortex, where there are different signaling mechanisms and information-processing functions," said Lisa Kilpatrick, PhD, a researcher in the Goodman-Luskin Microbiome Center focusing on brain signatures related to brain-body dysregulation, the study's first author. "Examining the microstructure at different cortical levels provides a better understanding of alterations in cell populations, processes and communication routes that may be affected by living in a disadvantaged neighborhood."

According to the results, worse ADI ratings were associated with communication changes in brain regions that are important for social interaction. Other changes occurred in regions involved in reward, emotion regulation, and higher cognitive processes -- and these changes appeared to be affected by trans-fatty acid intake. Together, the findings suggest that factors prevalent in disadvantaged neighborhoods that encourage poor diet and unhealthy weight gain "disrupt the flexibility of information processing involved in reward, emotion regulation, and cognition."

https://www.sciencedaily.com/releases/2023/09/230915105615.htm

New parent? Night shift? New analysis suggests ideal nap strategy to survive all-nighters

September 15, 2023

Science Daily/Hiroshima University

New analysis of pilot studies on night shift naps conducted from 2012 to 2018 revealed the ideal snoozing strategy that might help counteract drowsiness and fatigue during a 16-hour overnight duty. The findings can also benefit new parents.

Reanalysis of data showed that when staying up all night, scheduling two nap sessions -- a 90-minute one followed by a quick 30-minute shut-eye later -- is the optimal choice over a single 120-minute snooze in putting off drowsiness and fatigue. The study was published in the journal Scientific Reports.

"A 90-minute nap to maintain long-term performance and a 30-minute nap to maintain lower fatigue levels and fast reactions, as a strategic combination of naps, can be valuable for early morning work efficiency and safety," said study sole author Sanae Oriyama, a nursing science professor at Hiroshima University's Graduate School of Biomedical and Health Sciences.

Shift work is a norm in emergency sectors such as healthcare where round-the-clock access to services can be life-saving. And working double shifts on nontraditional hours isn't unheard of among medical professionals. However, night shift work is also known to increase the risk for sleep-related physical and mental health disorders and impair job performance.

During the daytime, our light-sensitive internal clock activates wakefulness. The opposite happens at nighttime when alertness dims as our biorhythm readies to switch off, elevating the likelihood of errors and accidents. In the medical field, this may inadvertently lead to serious harm to patients or to oneself. Naps are usually taken by shift workers to offset disruptions to the body clock.

In Japan, nurses are typically allowed to sleep up to two hours during 16-hour night shifts. Oriyama wanted to find out which napping schedule is the best in fighting off sleepiness and diminished cognitive function during such grueling work hours. And while at it, figure out how sleep quality factors in.

Single versus split naps

Oriyama reexamined past pilot studies she co-authored to compare alertness and cognitive performance after taking a nap and throughout a simulated 4 p.m. to 9 a.m. shift. The one-nap condition experiment was conducted in 2012, the two-nap in 2014, and the no-nap in 2018.

"I want to be able to combine multiple naps, depending on the type of work and time of day, and choose naps that are effective at reducing drowsiness, fatigue, and maintaining performance," she said.

She found that those who took a single 120-minute nap ending at midnight experienced worse drowsiness as soon as 4 a.m. and lasted until the end of the shift. However, participants who scheduled two naps -- the 90-minute one lasting until midnight and the 30-minute one ending at 3 a.m. -- staved off drowsiness until 6 a.m. Oriyama suggested adding an extra 30 minutes of shut-eye between 5-6 a.m. given that drowsiness might shoot up from 7-8 a.m.

As for fatigue, although all nap groups expressed significantly heightened levels of it from 4-9 a.m., the two-nap group experienced it at an intensity lower than the rest.

"During a night shift that, for example, lasts from 4 p.m. to 9 a.m. the next morning, a split nap of 90 minutes and 30 minutes, ending at 12 a.m. and 3 a.m., respectively, is thought to be more effective than a 120-minute monophasic nap ending at 12 a.m. when tasks requiring quick responses to maintain a high level of safety are scheduled between 2 a.m. and 9 a.m.," Oriyama said.

Finding the best nap length, timing

Both the single and split naps did not result in improved cognitive task performance. However, Oriyama noted that those who took longer to fall asleep during the 90-minute nap session showed poorer scores in the Uchida-Kraepelin test (UKT), a timed basic math exam meant to measure speed and accuracy in performing a task.

It takes 90 minutes to complete a full sleep cycle. And waking up before it is finished could exacerbate sleep inertia, the grogginess and disorientation felt upon first waking up. Similarly, the study found that if total sleep time is prolonged, fatigue and drowsiness could also increase.

Meanwhile, past research showed that a nap of 30 minutes or less could help boost vigilance, alertness, and energy levels.

The study also found that the timing of your nap plays a crucial role: the later you take it, the more potent it is in fending off sleepiness and exhaustion. However, delaying it too much could interfere with your focus as your sleep drive builds up.

"Hence, the ideal time for taking a nap and the ideal nap schedule during long night shifts need further elucidation," Oriyama said.

Beneficial for new parents, too

Oriyama said her findings could also be helpful to new parents.

"The results of this study can be applied not only to night shift workers but also to minimize sleep deprivation fatigue in mothers raising infants."

A total of 41 females in their 20s participated in the studies. Research participants were invited to a windowless and soundproofed laboratory for a 16-hour night shift simulation. The room temperature was kept at a comfortable 26 degrees Celsius and light intensity above work desks was set at 200 lux, the typical illuminance level in offices. All took the UKT each hour. Their hourly temperature, self-reported drowsiness and fatigue levels, heart rate, and blood pressure were also measured. After the tests, participants have free time to do anything they want on their desks like reading, drawing, or drinking water. During the scheduled nap time, they moved to a neighboring bedroom where they were allowed to darken the light according to their preference. Their sleep parameters were measured during this time.

https://www.sciencedaily.com/releases/2023/09/230915105258.htm

New evidence indicates patients recall death experiences after cardiac arrest

September 14, 2023

Science Daily/Elsevier

Up to an hour after their hearts had stopped, some patients revived by cardiopulmonary resuscitation (CPR) had clear memories afterward of experiencing death and had brain patterns while unconscious linked to thought and memory, report investigators in the journal Resuscitation, published by Elsevier.

In a study led by researchers at NYU Grossman School of Medicine, in cooperation with 25 mostly US and British hospitals, some survivors of cardiac arrest described lucid death experiences that occurred while they were seemingly unconscious. Despite immediate treatment, fewer than 10% of the 567 patients studied, who received CPR in the hospital, recovered sufficiently to be discharged. Four in 10 of patients who survived, however, recalled some degree of consciousness during CPR not captured by standard measures.

The study also found that in a subset of these patients, who received brain monitoring, nearly 40% had brain activity that returned to normal, or nearly normal, from a "flatline" state, at points even an hour into CPR. As captured by EEG, a technology that records brain activity with electrodes, the patients saw spikes in the gamma, delta, theta, alpha, and beta waves associated with higher mental function.

Survivors have long reported having heightened awareness and powerful, lucid experiences, say the study authors. These have included a perception of separation from the body, observing events without pain or distress, and a meaningful evaluation of their actions and relationships. This new work found these experiences of death to be different from hallucinations, delusions, illusions, dreams, or CPR-induced consciousness.

The study authors hypothesize that the "flatlined," dying brain removes natural inhibitory (braking) systems. These processes, known collectively as disinhibition, may open access to "new dimensions of reality," they say, including lucid recall of all stored memories from early childhood to death, evaluated from the perspective of morality. While no one knows the evolutionary purpose of this phenomenon, it "opens the door to a systematic exploration of what happens when a person dies."

Senior study author Sam Parnia, MD, PhD, associate professor in the Department of Medicine at NYU Langone Health and director of critical care and resuscitation research at NYU Langone, says, "Although doctors have long thought that the brain suffers permanent damage about 10 minutes after the heart stops supplying it with oxygen, our work found that the brain can show signs of electrical recovery long into ongoing CPR. This is the first large study to show that these recollections and brain wave changes may be signs of universal, shared elements of so-called near-death experiences."

Dr. Parnia adds, "These experiences provide a glimpse into a real, yet little understood dimension of human consciousness that becomes uncovered with death. The findings may also guide the design of new ways to restart the heart or prevent brain injuries and hold implications for transplantation."

Called the AWAreness during REsuscitation (AWARE)-II study -- it followed 567 men and women who suffered cardiac arrest during hospital stays between May 2017 and March 2020 in the United States and United Kingdom. Only hospitalized patients were enrolled to standardize the CPR and resuscitation methods used, as well as recording methods for brain activity. A subset of 85 patients received brain monitoring during CPR. Additional testimony from 126 community survivors of cardiac arrest with self-reported memories was also examined to provide greater understanding of the themes related to the recalled experience of death.

The study authors conclude that research to date has neither proved nor disproved the reality or meaning of patients' experiences and claims of awareness in relation to death. They say the recalled experience surrounding death merits further empirical investigation and plan to conduct studies that more precisely define biomarkers of clinical consciousness and that monitor the long-term psychological effects of resuscitation after cardiac arrest.

https://www.sciencedaily.com/releases/2023/09/230914175140.htm

A quarter of people are undoing the benefits of healthy meals by unhealthy snacking

September 14, 2023

Science Daily/King's College London

A quarter of people are undoing the benefits of healthy meals with unhealthy snacks, which increases the risk of strokes and cardiovascular disease.

The findings, published today in the European Journal of Nutrition by researchers from the School of Life Course & Population Sciences and ZOE, details the snacking habits of 854 people from the ZOE PREDICT study.

Researchers found that half of the participants do not match the healthiness of their meals to their snacks and vice versa. This difference has a negative effect on health measures, such as blood sugar and fat levels, and addressing this could be a simple diet strategy to improve health.

Dr Sarah Berry from King's College London and chief scientist at ZOE said: "Considering 95% of us snack, and that nearly a quarter of our calories come from snacks, swapping unhealthy snacks such as cookies, crisps and cakes to healthy snacks like fruit and nuts is a really simple way to improve your health."

The analysis showed that the UK is a nation of snackers, with 24% of our daily energy intake from snacks such as cereal bars, pastries and fruit. The average daily snack intake in people who snack -- 95% of the cohort -- was 2.28 snacks a day, with 47% of people eating two snacks a day and 29% of people eating more than two.

Contrary to popular belief, the analysis showed that snacking is not unhealthy -- as long as the snacks were healthy. People who ate high-quality snacks like nuts and fresh fruits frequently were more likely to have a healthy weight compared to those who don't snack at all or those who snack on unhealthy foods. Analysis also showed good quality snacks can also result in better metabolic health and decreased hunger.

However, a quarter (26%) of the participants reported eating healthy main meals and poor-quality snacks. Poor-quality snacks, such as highly processed food and sugary treats, were associated with poorer health markers and left people feeling hungry. Unhealthy snacks were linked with higher BMI, higher visceral fat mass and higher postprandial -- the period after eating a meal -- triglycerides concentrations, all of which are associated with metabolic disease such as stroke, cardiovascular disease and obesity.

The most popular snacks consumed were cookies, fruit, nuts and seeds, cheese and butter, cakes and pies and granola or cereal bars. The greatest contribution to calorie intake were cakes and pies (14%), breakfast cereals (13%), ice cream and frozen dairy desserts (12%), donuts and pastries (12%), candy (11%), cookies and brownies (11%), nuts and seeds (11%).

The timing of the snacking can also be crucial to your health, as analysis showed snacking after 9pm was associated with poorer blood markers compared to all other snacking times. Snackers at this time tended to eat energy-dense foods which were high in fat and sugar.

Dr Kate Bermingham from King's College London and senior scientist at ZOE said: "This study contributes to the existing literature that food quality is the driving factor in positive health outcomes from food. Making sure we eat a balanced diet of fruit, vegetables, protein and legumes is the best way to improve your health."

https://www.sciencedaily.com/releases/2023/09/230914224038.htm

All work and no play will really make a dull life

September 14, 2023

Science Daily/University of Essex

Prioritizing career goals over fun and freedom doesn't make your life better, researchers have found. The study across three countries discovered people who prioritized achievement over enjoyment were less happy on the next day.

The study across three countries led by the Department of Psychology's Dr Paul Hanel discovered people who prioritised achievement over enjoyment were less happy on the next day.

Whereas those who aimed for freedom said they had a 13% increase in well-being, recording better sleep quality and life satisfaction.

And participants who tried to relax and follow their hobbies recorded an average well-being boost of 8% and a 10% drop in stress and anxiety.

Dr Hanel worked with colleagues at the University of Bath on the Journal of Personality-published study.

For the first time, it explored how following various values impacts our happiness.

Dr Hanel said: "We all know the old saying 'All work and no play makes Jack a dull boy' and this study shows it might actually be true.

"There is no benefit to well-being in prioritising achievement over fun and autonomy.

"This research shows that there are real benefits to having a balanced life and taking time to focus on enjoying ourselves and following individual goals.

"Ironically by doing this, people could in fact be more successful as they will be more relaxed, happier and satisfied."

The study -Value Fulfilment and Well-being: Clarifying Directions Over Time -- examined more than 180 people in India, Turkey and the UK.

They filled in a diary across nine days and recorded how following different values affected them.

Interestingly all nationalities reported the same results with the following of 'hedonism' and 'self-direction' values leading to increased happiness.

'Achievement' and 'conformity' values had no impact on happiness whatsoever.

However, the researchers believe achievement could impact on happiness when linked to job satisfaction or the amount of days worked.

Professor Greg Maio, University of Bath, said: "This multination project was an exciting foray into questions about how values affect well-being in day-to-day life.

"People often spend most of their days working hard for their daily income, studies, and careers.

"Against this backdrop, where achievement-oriented values have ring-fenced a great portion of our time, we found that it helps to value freedom and other values just enough to bring in balance and recovery.

"In the future, it will be interesting to consider how this pattern interacts with relevant traits, such as conscientiousness, and situational contexts, such as type of employment."

It is hoped the research will now influence mental health provision and influence therapeutic give to clients.

Dr Hanel added: "Our research further shows that it might be more important to focus on increasing happiness rather than reducing anxiety and stress, which is of course also important, just not as much."

https://www.sciencedaily.com/releases/2023/09/230914103346.htm

Potential new approach to PTSD treatment

September 13, 2023

Science Daily/Louisiana State University Health Sciences Center

A research study has found that cerebellar inhibitory interneurons are essential for fear memory, a type of emotional memory formation. Inhibitory interneurons within the cerebellar circuitry act as gatekeepers and control the output of the cerebellar cortex. The formation of fear memory requires the activity of these interneurons. The findings may lead to a novel treatment approach for post-traumatic stress disorder.

An LSU Health New Orleans research study led by Siqiong June Liu, PhD, Professor of Cell Biology and Anatomy, has found that cerebellar inhibitory interneurons are essential for fear memory, a type of emotional memory formation. Inhibitory interneurons within the cerebellar circuitry act as gatekeepers and control the output of the cerebellar cortex. The formation of fear memory requires the activity of these interneurons. The findings, which may lead to a novel treatment approach for post-traumatic stress disorder, are published in Cell Reports.

"While synaptic plasticity is considered the basis of learning and memory, modifications of the intrinsic excitability of neurons can amplify the output of neuronal circuits and consequently change behavior," notes Dr. Liu. "In the cerebellum, we find that silencing molecular layer interneurons completely abolishes fear memory, revealing their critical role in memory consolidation."

The cerebellum is a brain region that is known to control motor coordination. Recent work has shown that it is also critical for the formation of memory, but not how the cerebellar circuitry accomplishes this function.

The research team found that fear conditioning suppresses hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and enhances cerebellar interneuron excitability. HCN currents are similar to pacemakers in the brain because they help regulate rhythmic activity and communication between brain cells. HCN loss is driven by a learning-induced decrease in endocannabinoid levels. When the activity of these neurons is suppressed, experimental animals do not remember the experience a few hours after learning.

"Our study reveals that activity in cerebellar interneurons drives fear memory formation via a learning-specific increase in intrinsic excitability," Liu concludes. "This highlights the importance of moving beyond traditional synaptic plasticity-focused investigations of memory formation and suggests a novel therapeutic approach for the treatment of PTSD."

https://www.sciencedaily.com/releases/2023/09/230913122754.htm

Inflammatory signs for adolescent depression differ between boys and girls

September 13, 2023

Science Daily/King's College London

New research led by the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King's College London has found that depression and the risk of depression are linked to different inflammatory proteins in boys and girls.

When inflammation occurs in the body a host of proteins are released into the blood called cytokines. Previous research has shown that higher levels of cytokines are associated with depression in adults, but little is known about this relationship in adolescence.

Researchers investigated sex-differences in the relationship between inflammatory proteins and depression. Published in the Journal of Affective Disorders, the study found that different cytokines were implicated in depression risk and severity in boys compared to girls. The research was part of the IDEA (Identifying Depression Early in Adolescence) project funded by MQ Mental Health Research.

To assess inflammation, researchers measured the blood cytokine levels in 75 adolescent boys and 75 adolescent girls (aged 14-16 years) from Brazil. The 150 participants had been recruited into three groups with equal numbers (50 participants in each group: 25 girls and 25 boys). The groups were those at low-risk for depression and not depressed, those at high risk of depression and not depressed, and those currently experiencing major depressive disorder (MDD).

The findings indicated that there are sex differences between the individual inflammatory proteins that are associated with depression in adolescents. Higher levels of the cytokine interleukin-2 (IL-2) were associated with both increased risk for depression and the severity of depressive symptoms in boys, but not in girls. However, higher levels of IL-6 were associated with severity of depression in girls, but not boys. In boys the levels of IL-2 were higher in the high-risk than the low-risk group and even higher in the group diagnosed with depression, indicating that in boys IL-2 levels in the blood could help indicate the onset of future depression.

Dr Zuzanna Zajkowska, Postdoctoral Researcher at King's IoPPN and first author of the study, said,

"This is the first study to show differences between boys and girls in the patterns of inflammation that are linked to the risk and development of adolescent depression. We found that the severity of depressive symptoms was associated with increased levels of the cytokine interleukin-2 in boys, but interleukin-6 in girls. We know more adolescent girls develop depression than boys and that the disorder takes a different course depending on sex so we hope that our findings will enable us to better understand why there are these differences and ultimately help develop more targeted treatments for different biological sexes."

Researchers recruited adolescents from public schools in Brazil. Risk of depression was assessed by a composite risk score for depression based on 11 sociodemographic variables that had been developed as part of the IDEA project. Adolescents completed several questionnaires, self-reporting their emotional difficulties, relationships, experiences, and mood. They also completed a clinical assessment with a child and adolescent psychiatrist.

Senior author on the study Professor Valeria Mondelli, Clinical Professor of Psychoneuroimmunology at King's IoPPN and theme-lead for Psychosis and Mood Disorders at the NIHR Maudsley BRC, said,

"Our findings suggest that inflammation and biological sex may have combined contribution to the risk for depression. We know that adolescence is a key time when many mental disorders first develop and by identifying which inflammatory proteins are linked to depression and how this is different between boys and girls we hope that our findings can pave the way to understanding what happens at this critical time in life. Our research highlights the importance of considering the combined impact of biology, psychology, and social factors to understand the mechanisms underlying depression."

The study is part of the Identifying Depression Early in Adolescence (IDEA) project, led by Professor Valeria Mondelli at King's IoPPN and funded by MQ Mental Health Research. The IDEA project is investigating how cultural, social, genetic and environmental factors lead to the development of depression in 10-24-year-olds across the UK, Brazil, Nigeria, Nepal, New Zealand and USA.

https://www.sciencedaily.com/releases/2023/09/230913122709.htm

How education, work and motherhood shape women's life 'pathways'

September 13, 2023

Science Daily/North Carolina State University

A new study from North Carolina State University and Duke University offers insights into the ways that education, work and motherhood shape the lives of women in the United States. In a longitudinal study of more than 8,100 women, the researchers found seven "pathways" that illustrate the way major life events can have long-term ripple effects.

"Our goal here was to examine how family, work and education influence each other in the lives of women, rather than viewing education as a separate process from work and family," says Anna Manzoni, co-author of a paper on the study and an associate professor of sociology at NC State. "Our approach highlights the fluidity of education in many women's lives, and challenges the idea that completing one's education and transitioning from school to a full-time job are essential elements of how we define adulthood."

For the study, researchers examined data from 8,101 women who participated in the National Longitudinal Study of Adolescent to Adult Health, which is a nationally representative panel study that followed people in the United States from youth through adulthood.

The researchers then conducted analyses of these data to find patterns and subgroups among study participants, which helped them identify distinct pathways or commonalities among subgroups. The researchers also assessed the extent to which these pathways related to the race and socioeconomic class of the study participants.

"We found that women's lives tend to take one of seven pathways, with six of those pathways broadly defined by when or if women become parents," Manzoni says. "These pathways really underscore the extent to which specific life events, opportunities or constraints can shape later patterns in women's lives. However, it's important to recognize that there are notable nuances in the way women's lives end up unfolding in more ways than one."

The first three pathways all include women who became parents between the ages of 18 and 25:

• Early Mothers with High School Interrupted (making up 13.29% of participants);

• Early Mothers with Limited Education (13.01%), which refers to women who obtained a high school diploma or GED;

• Early Mothers with Continuing Education (19.31%).

The second three pathways include women who got college degrees by the time they were 25:

• College then Work Focused (11.95%);

• College then Family Focused (8.97%); and

• Graduate Degree Professionals (13.31%).

The seventh pathway was Independents with Continuing Education (20.17%), which is largely made up of women who pursue education at community colleges and vocational schools into adulthood and are unlikely to marry or have children until they are in their 30s and 40s.

"These groups are based on various longitudinal patterns that we observe across the life course," says Jane Bo-Hyeong Lee, co-author of the paper and a research associate in Duke University's Center for Health Policy & Inequalities Research. "For example, about 24% of women in the Early Mothers with Limited Education pathway went on to get associate's degrees by the time they were in their late 30s or early 40s. However, this pattern is very different from that of women who postponed starting a family until they'd completed an advanced degree."

"Much of this is informed by socioeconomic background and the resources that women have access to," says Manzoni. "For example, the three college-centered pathways largely reflect the experiences of women who come from privileged socioeconomic backgrounds.

"This work is important because it provides a structured way of understanding the ways in which family, work and education influence each other in the lives of women," Manzoni says.

"Our work builds on previous research, many of which use qualitative methods or cross-sectional data," Lee adds. "We have the advantage of using a nationally representative dataset that followed these women for many years."

https://www.sciencedaily.com/releases/2023/09/230913122644.htm

Older adults with digestive diseases experience higher rates of loneliness, depression

September 12, 2023

Science Daily/Michigan Medicine - University of Michigan

A team of gastroenterologists and hepatologists examine psychosocial factors in older Americans with gastrointestinal conditions.

While life expectancy rates for older Americans are rising, nearly 40% of adults report living with a digestive disease of some kind.

"Many people don't realize that these conditions are very common in ambulatory care," said Michigan Medicine gastroenterologist Shirley Ann Cohen-Mekelburg, M.D., who specializes in conditions like inflammatory bowel disease, Crohn's disease and ulcerative colitis.

"Ultimately, this creates an excess in health care spending in the United States. Not only are these conditions debilitating for the millions of people living with them, but they're also very expensive to treat."

Cohen-Mekelburg says that in recent years, there has been a greater emphasis among providers in detecting why so many Americans are developing digestive diseases.

However, she notes that current approaches often fail to consider how things like psychosocial factors contribute to these conditions.

"As physicians, it's important for us to pay attention to psychosocial factors involved in the lives of our patients, but they often go overlooked," she said.

"These factors have the potential to significantly impact gastrointestinal health, and they also play a crucial role in the overall wellbeing of our patients."

This notion inspired Cohen-Mekelburg and a team of fellow gastroenterologists and hepatologists to examine the rates of loneliness, depression and social isolation in older adults both with and without digestive diseases.

Their findings were recently published in Clinical Gastroenterology and Hepatology.

Cohen-Mekelburg notes that the team also "wanted to quantify these numbers with self-reported rates of poor health."

"Our research involved analyzing data from 2008 to 2016 from the University of Michigan Health and Retirement Study.

This is a longitudinal panel study that involves a representative sample of approximately 20,000 individuals in the U.S. who are 50 years and older, as well as their spouses," she said.

"It's important to note that loneliness refers to the subjective distressed feeling of being alone or lacking companionship. The correlation between loneliness and depression is well established."

However, Cohen-Mekelburg adds that social isolation refers to the "objective physical separation from other people, which is independent of psychological well-being."

"Therefore, there are people who live in isolation but are well-adapted, not lonely and report high psychological wellbeing. But on the other hand, there are also people who are socially connected, yet suffer from low psychological wellbeing and loneliness. This, despite having a strong social network."

Out of a pool of 7,110 participants, the team identified 56% of individuals with a digestive disease and 44% without one.

"Overall, 60.4% and 55.6% of respondents with and without digestive diseases reported loneliness, while 12.7% and 7.5% reported severe depression, and 8.9% and 8.7% reported social isolation, respectively," said Cohen-Mekelburg.

"We found that individuals with a digestive disease were more likely to report 'poor-or-fair' health when compared to those without one. And among patients with a digestive disease, loneliness, as well as moderate to severe depression, were associated with greater odds of self-reporting 'poor-or-fair' health."

Cohen-Mekelburg says that she hopes these findings eventually empower gastroenterologists to "screen patients for depression and loneliness," in addition to their physical symptoms. "By doing this, providers can better establish care pathways for mental health treatment for their patients, which is hugely important," she said.

"Our research shows that gastroenterologists are in a unique position to help their patients achieve good overall health. If you're a clinician who also happens to treat older adults, even better. Being aware of the link between loneliness, depressive symptoms and digestive diseases can really benefit your patients from a holistic perspective."

https://www.sciencedaily.com/releases/2023/09/230912165720.htm

Your body's own cannabinoid molecules calm you during stress

Scientists discover how stress activates the same receptors as THC

September 12, 2023

Science Daily/Northwestern University

When you are under stress, your brain may release its own cannabinoid molecules to calm you down, activating the same brain receptors as THC derived from cannabis plants.

But the brain activity patterns and neural circuits that are regulated by these brain-derived cannabinoid molecules were not well known.

A new Northwestern Medicine study in mice has discovered that a key emotional brain center, the amygdala, releases endogenous (the body's own) cannabinoid molecules under stress, and these molecules dampen the incoming stress alarm from the hippocampus, a memory and emotion center in the brain. These results provide more support for the hypothesis that these endogenous cannabinoid molecules are a body's natural coping response to stress.

Stress exposure heightens risk for the development or worsening of psychiatric disorders from generalized anxiety and major depression to post-traumatic stress disorder (PTSD).

"Understanding how the brain adapts to stress at the molecular, cellular and circuit level could provide critical insight into how stress is translated into mood disorders and may reveal novel therapeutic targets for the treatment of stress-related disorders," said corresponding study author Dr. Sachi Patel, chair of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine and a Northwestern Medicine psychiatrist.

The study could indicate that impairments in this endogenous cannabinoid signaling system in the brain could lead to a greater susceptibility to developing stress-related psychiatric disorders including depression and PTSD, although this remains to be determined in humans, Patel said.

The study will be published Sept. 12 in Cell Reports.

For the study, Northwestern scientists used a new protein sensor that can detect the presence of these cannabinoid molecules at specific brain synapses in real time to show that specific high-frequency patterns of amygdala activity can generate these molecules. The sensor also showed that these molecules were released as a result of several different types of stress in mice.

When scientists removed the target of these cannabinoids, the cannabinoid receptor type 1, it resulted in poorer ability to cope with stress and motivational deficits in the mice. Specifically, when the receptor target of these endogenous cannabinoids was removed at hippocampal-amygdala synapses, mice adopted more passive and immobile responses to stress and had a lower preference to drink a sweetened sucrose water after stress exposure. The latter finding may relate to anhedonia, or the decrease in pleasure, often experienced by patients with stress-related disorders such as depression and PTSD.

One of the leading signaling systems that has been identified as a prominent drug-development candidate for stress-related psychiatric disorders is the endocannabinoid system, Patel said.

"Determining whether increasing levels of endogenous cannabinoids can be used as potential therapeutics for stress-related disorders is a next logical step from this study and our previous work," said Patel, also the Lizzie Gilman Professor of Psychiatry and Behavioral Sciences. "There are ongoing clinical trials in this area that may be able to answer this question in the near future."

Other Northwestern authors include Farhana Yasmin, Amanda Morgan and Keenan Johnson.

The title of the article is "Endocannabinoid release at ventral hippocampal-amygdala synapses regulates stress-induced behavioral adaptation."

https://www.sciencedaily.com/releases/2023/09/230912113528.htm

Large amounts of sedentary time linked with higher risk of dementia in older adults

September 12, 2023

Science Daily/University of Southern California

Researchers have used machine learning to explore the links between sedentary behavior and dementia, finding that the total time spent sedentary matters for brain aging.

Adults aged 60 and older who spend more time engaging in sedentary behaviors like sitting while watching TV or driving may be at increased risk of developing dementia, according to a new study by USC and University of Arizona researchers.

Their study showed the risk of dementia significantly increases among adults who spend over 10 hours a day engaging in sedentary behaviors like sitting -- a notable finding considering the average American is sedentary for about 9.5 hours each day.

The study, published on Tuesday, September 12 in JAMA, also revealed the way sedentary behavior is accumulated over the course of the day didn't matter as much as the total time spent sedentary each day. Whether spent in extended periods spanning several hours or spread out intermittently throughout the day, total sedentary behavior had a similar association with dementia according to study author David Raichlen.

"Many of us are familiar with the common advice to break up long periods of sitting by getting up every 30 minutes or so to stand or walk around. We wanted to see if those types of patterns are associated with dementia risk. We found that once you take into account the total time spent sedentary, the length of individual sedentary periods didn't really matter," said Raichlen, professor of biological sciences and anthropology at the USC Dornsife College of Letters, Arts and Sciences.

Researchers used data from the U.K. Biobank, a large-scale biomedical database of participants across the United Kingdom, to investigate possible links between sedentary behavior and dementia risk.

As part of a U.K. Biobank sub-study, over 100,000 adults agreed to wear accelerometers, wrist-worn devices for measuring movement, for 24 hours per day for one week. The researchers focused on a sample of approximately 50,000 adults from this sub-study over the age of 60 who did not have a diagnosis of dementia at the start of the study.

The researchers then applied a machine-learning algorithm to analyze the large dataset of accelerometer readings and classify behaviors based on different intensities of physical activity. The algorithm was able to discern between different types of activity such as sedentary behavior versus sleeping. The accelerometer data, combined with advanced computing techniques, provided researchers with an objective measure of the time spent engaging in different types of sedentary behaviors.

After an average of six years of follow-up, the researchers used inpatient hospital records and death registry data to determine dementia diagnosis. They found 414 cases positive for dementia.

Then, the team adjusted their statistical analysis for certain demographics (e.g., age, sex, education level, race/ethnicity, chronic conditions, genetics) and lifestyle characteristics (physical activity, diet, smoking and alcohol use, self-reported mental health) that could affect brain health.

Total time spent sedentary each day drives dementia risk

While high amounts of sedentary behavior were linked with increased risk of dementia, the researchers found that there were certain amounts of sedentary behavior that were not associated with dementia.

"We were surprised to find that the risk of dementia begins to rapidly increase after 10 hours spent sedentary each day, regardless of how the sedentary time was accumulated. This suggests that it is the total time spent sedentary that drove the relationship between sedentary behavior and dementia risk, but importantly lower levels of sedentary behavior, up to around 10 hours, were not associated with increased risk," said study author Gene Alexander, professor of psychology and psychiatry at the Evelyn F. McKnight Brain Institute at the University of Arizona and Arizona Alzheimer's Disease Research Center.

"This should provide some reassurance to those of us with office jobs that involve prolonged periods of sitting, as long we limit our total daily time spent sedentary," said Raichlen.

The study builds on their previous research, which used self-reported health data to investigate how certain types of sedentary behavior, like sitting and watching TV, affect dementia risk more than others.

"Our latest study is part of our larger effort to understand how sedentary behavior affects brain health from multiple perspectives. In this case, wearable accelerometers provide an objective view of how much time people dedicate to sedentary behavior that complements our past analyses," said Raichlen.

More research is needed to establish causality and whether physical activity can mitigate the risk of developing dementia, the authors said.

https://www.sciencedaily.com/releases/2023/09/230912113525.htm

Healthy lifestyle can help prevent depression -- and new research may explain why

September 11, 2023

Science Daily/University of Cambridge

A healthy lifestyle that involves moderate alcohol consumption, a healthy diet, regular physical activity, healthy sleep and frequent social connection, while avoiding smoking and too much sedentary behaviour, reduces the risk of depression, new research has found.

In research published today in Nature Mental Health, an international team of researchers, including from the University of Cambridge and Fudan University, looked at a combination of factors including lifestyle factors, genetics, brain structure and our immune and metabolic systems to identify the underlying mechanisms that might explain this link.

According to the World Health Organization, around one in 20 adults experiences depression, and the condition poses a significant burden on public health worldwide. The factors that influence the onset of depression are complicated and include a mixture of biological and lifestyle factors.

To better understand the relationship between these factors and depression, the researchers turned to the UK Biobank, a biomedical database and research resource containing anonymised genetic, lifestyle and health information about its participants.

By examining data from almost 290,000 people -- of whom 13,000 had depression -- followed over a nine-year period, the team was able to identify seven healthy lifestyle factors linked with a lower risk of depression. These were:

• moderate alcohol consumption

• healthy diet

• regular physical activity

• healthy sleep

• never smoking

• low-to-moderate sedentary behaviour

• frequent social connection

Of all of these factors, having a good night's sleep -- between seven and nine hours a night -- made the biggest difference, reducing the risk of depression, including single depressive episodes and treatment-resistant depression, by 22%.

Frequent social connection, which in general reduced the risk of depression by 18%, was the most protective against recurrent depressive disorder.

Moderate alcohol consumption decreased the risk of depression by 11%, healthy diet by 6%, regular physical activity by 14%, never smoking by 20%, and low-to-moderate sedentary behaviour by 13%.

Based on the number of healthy lifestyle factors an individual adhered to, they were assigned to one of three groups: unfavourable, intermediate, and favourable lifestyle. Individuals in the intermediate group were around 41% less likely to develop depression compared to those in the unfavourable lifestyle, while those in the favourable lifestyle group were 57% less likely.

The team then examined the DNA of the participants, assigning each a genetic risk score. This score was based on the number of genetic variants an individual carried that have a known link to risk of depression. Those with the lowest genetic risk score were 25% less likely to develop depression when compared to those with the highest score -- a much smaller impact than lifestyle.

In people at high, medium, and low genetic risk for depression, the team further found that a healthy lifestyle can cut the risk of depression. This research underlines the importance of living a healthy lifestyle for preventing depression, regardless of a person's genetic risk.

Professor Barbara Sahakian, from the Department of Psychiatry at the University of Cambridge, said: "Although our DNA -- the genetic hand we've been dealt -- can increase our risk of depression, we've shown that a healthy lifestyle is potentially more important.

"Some of these lifestyle factors are things we have a degree control over, so trying to find ways to improve them -- making sure we have a good night's sleep and getting out to see friends, for example -- could make a real difference to people's lives."

To understand why a healthy lifestyle might reduce the risk of depression, the team studied a number of other factors.

First off, they examined MRI brain scans from just under 33,000 participants and found a number of regions of the brain where a larger volume -- more neurons and connections -- was linked to a healthy lifestyle. These included the pallidum, thalamus, amygdala and hippocampus.

Next, the team looked for markers in the blood that indicated problems with the immune system or metabolism (how we process food and produce energy). Among those markers found to be linked to lifestyle were the C-reactive protein, a molecule produced in the body in response to stress, and triglycerides, one of the primary forms of fat that the body uses to store energy for later.

These links are supported by a number of previous studies. For example, exposure to stress in life can affect how well we are able to regulate blood sugar, which may lead to a deterioration of immune function and accelerate age-related damage to cells and molecules in the body. Poor physical activity and lack of sleep can damage the body's ability to respond to stress. Loneliness and lack of social support have been found to increase the risk of infection and increase markers of immune deficiency.

The team found that the pathway from lifestyle to immune and metabolic functions was the most significant. In other words, a poorer lifestyle impacts on our immune system and metabolism, which in turn increases our risk of depression.

Dr Christelle Langley, also from the Department of Psychiatry at the University of Cambridge, said: "We're used to thinking of a healthy lifestyle as being important to our physical health, but it's just as important for our mental health. It's good for our brain health and cognition, but also indirectly by promoting a healthier immune system and better metabolism."

Professor Jianfeng Feng, from Fudan University and Warwick University, added: "We know that depression can start as early as in adolescence or young adulthood, so educating young people on the importance of a healthy lifestyle and its impact on mental health should begin in schools."

https://www.sciencedaily.com/releases/2023/09/230911141148.htm

'Night owls' more likely than 'early birds' to develop diabetes

September 11, 2023

Science Daily/Brigham and Women's Hospital

A new study has an important message for people who consider themselves night owls. Investigators from Brigham and Women's Hospital, a founding member of the Mass General Brigham healthcare system, found that people with later sleep and wake times had less healthy lifestyles and were at greater risk of developing diabetes than those with early-bird sleep habits.

Investigators found evening 'chronotype,' or going to bed late and waking up late, was associated with a 19 percent increased risk of diabetes after accounting for lifestyle factors

A new study has an important message for people who consider themselves night owls. Investigators from Brigham and Women's Hospital, a founding member of the Mass General Brigham healthcare system, found that people with later sleep and wake times had less healthy lifestyles and were at greater risk of developing diabetes than those with early-bird sleep habits. Their results are published in the Annals of Internal Medicine.

"Chronotype, or circadian preference, refers to a person's preferred timing of sleep and waking and is partly genetically determined so it may be difficult to change," said corresponding author Tianyi Huang, MSc, ScD, an associate epidemiologist in the Brigham's Channing Division of Network Medicine. "People who think they are 'night owls' may need to pay more attention to their lifestyle because their evening chronotype may add increased risk for type 2 diabetes."

The researchers previously found that people with more irregular sleep schedules are at higher risk of developing diabetes and cardiovascular disease and that people with evening chronotypes are more likely to have irregular sleep patterns. For this study, they wanted to understand the relationship between chronotype and diabetes risk and looked at the role of lifestyle factors as well.

The team analyzed data from 63,676 female nurses from the Nurses' Health Study II collected from 2009-2017 and included self-reported chronotype (the extent to which participants perceived themselves to be an evening person or a morning person), diet quality, weight and body mass index, sleep timing, smoking behaviors, alcohol use, physical activity, and family history of diabetes. The team determined diabetes status from the participants' self-reports and medical records.

The Nurses' Health Study II, a joint effort between the Brigham's Channing Division of Network Medicine and Harvard T.H. Chan School of Public Health, is among the largest investigations into risk factors for major chronic diseases in women. One of the study's strengths is its regular follow-up of study participants and repeated assessment of health and lifestyle factors.

Approximately 11 percent of participants reported having a 'definite evening' chronotype and about 35 percent reported having 'definite morning' chronotype. The remaining population, around half, were labeled as 'intermediate,' meaning they either identified as being neither a morning nor evening type or as being only slightly more one than the other.

The evening chronotype was associated with a 72 percent increased risk for diabetes before accounting for lifestyle factors. After accounting for lifestyle factors, evening chronotype was associated with a 19 percent increased risk of diabetes. Among those in the study with the healthiest lifestyles, only 6 percent had evening chronotypes. Among those with the unhealthiest lifestyles 25 percent were evening chronotypes.

Those with evening chronotypes were found to be more likely to drink alcohol in higher quantities, have a low-quality food diet, get less hours of sleep per night, currently smoke, and have weight, BMI, and physical activity rates in the unhealthy range.

"When we controlled for unhealthy lifestyle behaviors, the strong association between chronotype and diabetes risk was reduced but still remained, which means that lifestyle factors explain a notable proportion of this association," said first author Sina Kianersi, DVM, PhD, a postdoctoral research fellow in the Brigham's Channing Division of Network Medicine.

They also found the association between evening chronotype and diabetes risk only in those nurses who worked day shifts and not those who worked overnight shifts.

"When chronotype was not matched with work hours we saw an increase in type 2 diabetes risk," said Huang. "That was another very interesting finding suggesting that more personalized work scheduling could be beneficial."

The Nurses' Health Study is comprised mainly of white female nurses -- future investigations will be needed to determine if the patterns detected here are consistent across populations. The study's results point to associations but cannot determine causality -- it's possible that other factors may contribute to a person's chronotype, propensity for unhealthy habits and risk of diabetes.

Next, the researchers plan to investigate genetic determinants of chronotype and its association with cardiovascular disease, in addition to diabetes, in larger, more diverse populations.

"If we are able to determine a causal link between chronotype and diabetes or other diseases, physicians could better tailor prevention strategies for their patients," says Kianersi.

https://www.sciencedaily.com/releases/2023/09/230911191004.htm

Hobbies linked to lower depression levels among older people

September 11, 2023

Science Daily/University College London

A new study aimed to see if the benefits of hobbies were consistent in different national settings, and looked at data from 93,263 people aged 65 or over who had enrolled in five existing longitudinal studies in England, Japan, United States, China and 12 European countries.

Having a hobby is linked to fewer depressive symptoms and higher levels of happiness, self-reported health and life satisfaction among people aged 65 and over, and this holds true across 16 countries on three continents, according to a new study led by UCL (University College London) researchers.

The study, published in the journal Nature Medicine, aimed to see if the benefits of hobbies were consistent in different national settings, and looked at data from 93,263 people aged 65 or over who had enrolled in five existing longitudinal studies in England, Japan, United States, China and 12 European countries.

Analysing data from participants spanning four to eight years, the researchers found that having a hobby was also linked to subsequent decreases in depressive symptoms and increases in happiness and life satisfaction, suggesting there might be a causal effect, although as an observational study it could not prove causality.

These results remained after adjusting for other factors such as partnership status, employment and household income.

The study found the benefits of having a hobby were relatively universal, with only small differences between countries.

Lead author Dr Karen Mak (UCL Institute of Epidemiology & Health Care) said: "Our study shows the potential of hobbies to protect older people from age-related decline in mental health and wellbeing. This potential is consistent across many countries and cultural settings.

"Of the four outcomes, life satisfaction was most strongly linked to hobby engagement. Hobbies may contribute to life satisfaction in our later years through many mechanisms, including feeling in control of our minds and bodies, finding a purpose in life, and feeling competent in tackling daily issues.

"Theoretical work suggests the relationship between hobbies and wellbeing may cut both ways -- that people with better mental health may be more likely to take up a hobby, and persisting with a hobby may help us to retain improved life satisfaction.

"Our research also supports policymakers in promoting access to hobbies among older people as a way to enhance their wellbeing and health."

Hobbies, defined as activities people engage in during their leisure time for pleasure, might range from volunteering or being part of a club to reading, gardening, playing games, and arts and crafts.

The researchers found the proportion of people who said they had a hobby varied considerably between countries, with 51% of study participants in Spain reporting having a hobby, compared to 96% in Denmark, 95.8% in Sweden and 94.4% in Switzerland.

China had the lowest level of hobby engagement, at 37.6%, but researchers cautioned that study respondents in China were asked only about social hobbies, not hobbies in general.

In countries with better life expectancy and national happiness levels, more people reported having a hobby, and also the link between wellbeing and having a hobby was stronger in those countries.

The five longitudinal studies were: the English Longitudinal Study of Ageing (ELSA), the Japan Gerontological Evaluation Study (JAGES), US Health and Retirement Study (HRS), Survey of Health, Ageing and Retirement in Europe (SHARE), and China Health and Retirement Longitudinal Study (CHARLS). In ELSA, JAGES, and HRS, participants were asked about hobbies and the word was not defined; in SHARE and CHARLS, participants were asked if they engaged in a specific list of hobbies.

https://www.sciencedaily.com/releases/2023/09/230911141131.htm