Depressed or anxious teens risk heart attacks in middle age

August 26, 2020

Science Daily/European Society of Cardiology

Depression or anxiety in adolescence is linked with a 20% greater likelihood of having a heart attack mid-life, according to research released today at ESC Congress 2020.1

In a warning to parents, study author Dr. Cecilia Bergh of Örebro University in Sweden, said: "Be vigilant and look for signs of stress, depression or anxiety that is beyond the normal teenage angst: seek help if there seems to be a persistent problem (telephone helplines may be particularly helpful during the COVID-19 pandemic). If a healthy lifestyle is encouraged as early as possible in childhood and adolescence it is more likely to persist into adulthood and improve long-term health."

There are indications that mental well-being is declining in young people. This study investigated whether conditions like depression in adolescence (age 18 or 19) are associated with a higher risk of cardiovascular disease in adulthood. The researchers also examined the possible role of stress resilience (ability to cope with stress in everyday life) in helping to explain any associations.

The study included 238,013 men born between 1952 and 1956 who underwent extensive examinations in late adolescence (as part of their assessment for compulsory military service) and were then followed into middle age (up to the age of 58 years). The assessments at the age of 18 or 19 years included medical, psychiatric, and physical examinations by physicians and psychologists.

Stress resilience was measured by an interview with a psychologist and a questionnaire, and based on familial, medical, social, behavioural and personality characteristics.

A total of 34,503 men were diagnosed with a non-psychotic mental disorder (such as depression or anxiety) at conscription. Follow-up for cardiovascular disease was through hospital medical records.

The study found that a mental disorder in adolescence was associated with the risk of having a myocardial infarction (heart attack) by middle age. Compared to men without a mental illness in adolescence, the risk of myocardial infarction was 20% higher among men with a diagnosis -- even after taking into account other characteristics in adolescence such as blood pressure, body mass index, general health, and parental socioeconomic status.

The association between mental illness and heart attack was partly -- but not completely -- explained by poorer stress resilience and lower physical fitness in teenagers with a mental illness. "We already knew that men who were physically fit in adolescence seem less likely to maintain fitness in later years if they have low stress resilience," said Dr. Bergh. "Our previous research has also shown that low stress resilience is also coupled with a greater tendency towards addictive behaviour, signalled by higher risks of smoking, alcohol consumption and other drug use."

Dr. Bergh said: "Better fitness in adolescence is likely to help protect against later heart disease, particularly if people stay fit as they age. Physical activity may also alleviate some of the negative consequences of stress. This is relevant to all adolescents, but those with poorer wellbeing could benefit from additional support to encourage exercise and to develop strategies to deal with stress."

https://www.sciencedaily.com/releases/2020/08/200826083017.htm

Brain networks come 'online' during adolescence to prepare teenagers for adult life

Brain networks come 'online' during adolescence to prepare teenagers for adult life

January 29, 2020

Science Daily/University of Cambridge

New brain networks come 'online' during adolescence, allowing teenagers to develop more complex adult social skills, but potentially putting them at increased risk of mental illness, according to new research published in the Proceedings of the National Academy of Sciences (PNAS).

Adolescence is a time of major change in life, with increasing social and cognitive skills and independence, but also increased risk of mental illness. While it is clear that these changes in the mind must reflect developmental changes in the brain, it has been unclear how exactly the function of the human brain matures as people grow up from children to young adults.

A team based in the University of Cambridge and University College London has published a major new research study that helps us understand more clearly the development of the adolescent brain.

The study collected functional magnetic resonance imaging (fMRI) data on brain activity from 298 healthy young people, aged 14-25 years, each scanned on one to three occasions about 6 to 12 months apart. In each scanning session, the participants lay quietly in the scanner so that the researchers could analyse the pattern of connections between different brain regions while the brain was in a resting state.

The team discovered that the functional connectivity of the human brain -- in other words, how different regions of the brain 'talk' to each other -- changes in two main ways during adolescence.

The brain regions that are important for vision, movement, and other basic faculties were strongly connected at the age of 14 and became even more strongly connected by the age of 25. This was called a 'conservative' pattern of change, as areas of the brain that were rich in connections at the start of adolescence become even richer during the transition to adulthood.

However, the brain regions that are important for more advanced social skills, such as being able to imagine how someone else is thinking or feeling (so-called theory of mind), showed a very different pattern of change. In these regions, connections were redistributed over the course of adolescence: connections that were initially weak became stronger, and connections that were initially strong became weaker. This was called a 'disruptive' pattern of change, as areas that were poor in their connections became richer, and areas that were rich became poorer.

By comparing the fMRI results to other data on the brain, the researchers found that the network of regions that showed the disruptive pattern of change during adolescence had high levels of metabolic activity typically associated with active re-modelling of connections between nerve cells.

Dr Petra Vértes, joint senior author of the paper and a Fellow of the mental health research charity MQ, said: "From the results of these brain scans, it appears that the acquisition of new, more adult skills during adolescence depends on the active, disruptive formation of new connections between brain regions, bringing new brain networks 'online' for the first time to deliver advanced social and other skills as people grow older."

Professor Ed Bullmore, joint senior author of the paper and head of the Department of Psychiatry at Cambridge, said: "We know that depression, anxiety and other mental health disorders often occur for the first time in adolescence -- but we don't know why. These results show us that active re-modelling of brain networks is ongoing during the teenage years and deeper understanding of brain development could lead to deeper understanding of the causes of mental illness in young people."

Measuring functional connectivity in the brain presents particular challenges, as Dr František Váša, who led the study as a Gates Cambridge Trust PhD Scholar, and is now at King's College London, explained.

"Studying brain functional connectivity with fMRI is tricky as even the slightest head movement can corrupt the data -- this is especially problematic when studying adolescent development as younger people find it harder to keep still during the scan," he said. "Here, we used three different approaches for removing signatures of head movement from the data, and obtained consistent results, which made us confident that our conclusions are not related to head movement, but to developmental changes in the adolescent brain."

The study was supported by the Wellcome Trust.

https://www.sciencedaily.com/releases/2020/01/200129104705.htm

Your nose knows when it comes to stronger memories

New research points to value of unpleasant smells in strengthening recall

June 19, 2019

Science Daily/New York University

Memories are stronger when the original experiences are accompanied by unpleasant odors, a team of researchers has found. The study broadens our understanding of what can drive Pavlovian responses and points to how negative experiences influence our ability to recall past events.

"These results demonstrate that bad smells are capable of producing memory enhancements in both adolescents and adults, pointing to new ways to study how we learn from and remember positive and negative experiences," explains Catherine Hartley, an assistant professor in New York University's Department of Psychology and the senior author of the paper, which appears in the journal Learning and Memory.

"Because our findings spanned different age groups, this study suggests that aversive odors might be used in the future to examine emotional learning and memory processes across development," adds Alexandra Cohen, an NYU postdoctoral fellow and the paper's lead author.

The impact of negative experiences on memory has long been shown -- and is familiar to us. For example, if you are bitten by a dog, you may develop a negative memory of the dog that bit you, and your negative association may also go on to generalize to all dogs. Moreover, because of the trauma surrounding the bite, you are likely to have a better recollection of it than you would other past experiences with dogs.

"The generalization and persistence in memory of learned negative associations are core features of anxiety disorders, which often emerge during adolescence," notes Hartley.

In order to better understand how learned negative associations influence memory during this stage of development, the researchers designed and administered a Pavlovian learning task to individuals aged 13 to 25. Mild electrical shocks are often used in this type of learning task. In this study, the researchers used bad smells because they can be ethically administered in studying children.

The task included the viewing of a series of images belonging to one of two conceptual categories: objects (e.g., a chair) and scenes (e.g., a snow-capped mountain). As the study's participants viewed the images, they wore a nasal mask connected to an olfactometer. While participants viewed images from one category, unpleasant smells were sometimes circulated through the device to the mask; while viewing images from the other category, unscented air was used. This allowed the researchers to examine memory for images associated with a bad smell as well as for generalization to related images. In other words, if the image of a chair was associated with a bad smell, would memory be enhanced only for the chair or for objects in general?

What constitutes a "bad" odor is somewhat subjective. In order to determine which odors the participants found unlikable, the researchers had the subjects -- prior to the start of the experiment -- breathe in a variety of odors and indicate which ones they thought were unpleasant. The odors were blends of chemical compounds provided by a local perfumer and included scents such as rotting fish and manure.

As the subjects viewed the images, the scientists measured perspiration from the palm of the subjects' hands as an index of arousal -- a common research technique used to confirm the creation of a negative association (in this case, of a bad smell). A day later, researchers tested participants' memory for the images.

Their findings showed that both adolescents and adults showed better memory specifically for images paired with the bad smell 24 hours after they saw these images. They also found that individuals with larger arousal responses at the point when they might experience either a bad smell or clean air while viewing the image, regardless of whether or not a smell was actually delivered, had better memory 24 hours later. This suggests that unpredictability or surprise associated with the outcome leads to better memory.

https://www.sciencedaily.com/releases/2019/06/190619085701.htm