Sitting still linked to increased risk of depression in adolescents

February 11, 2020

Science Daily/University College London

Too much time sitting still -- sedentary behaviour -- is linked to an increased risk of depressive symptoms in adolescents, finds a new UCL-led study.

The Lancet Psychiatry study found that an additional 60 minutes of light activity (such as walking or doing chores) daily at age 12 was associated with a 10% reduction in depressive symptoms at age 18.

"Our findings show that young people who are inactive for large proportions of the day throughout adolescence face a greater risk of depression by age 18. We found that it's not just more intense forms of activity that are good for our mental health, but any degree of physical activity that can reduce the time we spend sitting down is likely to be beneficial," said the study's lead author, PhD student Aaron Kandola (UCL Psychiatry).

"We should be encouraging people of all ages to move more, and to sit less, as it's good for both our physical and mental health."

The research team used data from 4,257 adolescents, who have been participating in longitudinal research from birth as part of the University of Bristol's Children of the 90s cohort study. The children wore accelerometers to track their movement for at least 10 hours over at least three days, at ages 12, 14 and 16.

The accelerometers reported whether the child was engaging in light activity (which could include walking or hobbies such as playing an instrument or painting), engaging in moderate-to-physical activity (such as running or cycling), or if they were sedentary. The use of accelerometers provided more reliable data than previous studies which have relied on people self-reporting their activity, which have yielded inconsistent results.

Depressive symptoms, such as low mood, loss of pleasure and poor concentration, were measured with a clinical questionnaire. The questionnaire measures depressive symptoms and their severity on a spectrum, rather than providing a clinical diagnosis.

Between the ages of 12 and 16, total physical activity declined across the cohort, which was mainly due to a decrease in light activity (from an average of five hours, 26 minutes to four hours, five minutes) and an increase in sedentary behaviour (from an average of seven hours and 10 minutes to eight hours and 43 minutes).

The researchers found that every additional 60 minutes of sedentary behaviour per day at age 12, 14 and 16 was associated with an increase in depression score of 11.1%, 8% or 10.5%, respectively, by age 18. Those with consistently high amounts of time spent sedentary at all three ages had 28.2% higher depression scores by age 18.

Every additional hour of light physical activity per day at age 12, 14 and 16 was associated with depression scores at age 18 that were 9.6%, 7.8% and 11.1% lower, respectively.

The researchers found some associations between moderate-to-vigorous activity at earlier ages and reduced depressive symptoms, although they caution that their data was weaker due to low levels of activity of such intensity in the cohort (averaging around 20 minutes per day), so the findings do not clarify whether moderate-to-vigorous activity is any less beneficial than light activity.

While the researchers cannot confirm that the activity levels caused changes to depressive symptoms, the researchers accounted for potentially confounding factors such as socioeconomic status, parental history of mental health, and length of time wearing the accelerometer, and avoided the possibility of reverse causation by adjusting their analysis to account for people with depressive symptoms at the study outset.

"Worryingly, the amount of time that young people spend inactive has been steadily rising for years, but there has been a surprising lack of high quality research into how this could affect mental health. The number of young people with depression also appears to be growing and our study suggests that these two trends may be linked," Kandola added.

The study's senior author, Dr Joseph Hayes (UCL Psychiatry and Camden and Islington NHS Foundation Trust), said: "A lot of initiatives promote exercise in young people, but our findings suggest that light activity should be given more attention as well."

"Light activity could be particularly useful because it doesn't require much effort and it's easy to fit into the daily routines of most young people. Schools could integrate light activity into their pupils' days, such as with standing or active lessons. Small changes to our environments could make it easier for all of us to be a little bit less sedentary," he added.

https://www.sciencedaily.com/releases/2020/02/200211193051.htm

Study takes a stand against prolonged sitting

Solutions to lower health risks for students and faculty include stretch breaks, more open classrooms

February 6, 2020

Science Daily/University of California - Los Angeles

A new study shows classrooms remain overlooked when it comes to the health risks of sitting still for too long. Researchers found most students don't realize the health risks can't be counteracted by later exercise, and perhaps unsurprisingly, students feel it is socially unacceptable to take a walk while the professor is still leading class. The researchers have solutions like building open classrooms and offering instructor-led stretch breaks.

In many workplaces, standing desks and walking meetings are addressing the health dangers of sitting too long each day, but for universities, the natural question is how to make such adjustments for classrooms.

The question appealed to emerita dance professor Angelia Leung from the UCLA Department of World Arts & Cultures/Dance. Sitting too long was never an issue for Leung's students. But for most college students, desk time is more common than dance time. In an unusual collaboration between the arts and sciences, Leung partnered with Burt Cowgill, an assistant adjunct professor with the UCLA Fielding School of Public Health, to find ways to help students stand up.

The team's research, published in the Journal of American College Health on Feb. 6, hit upon solutions that students and faculty can agree on. However, all the solutions, the researchers said, would work best if joined with an effort to raise awareness about the health risks of extended sitting, aimed at shifting cultural expectations and norms about classroom etiquette.

Studies have linked prolonged sitting with health concerns such as heart disease, cancer, depression, diabetes and obesity. Research shows that breaking up long periods of sitting with movement at least once an hour reduces those risks, while regular exercise at other times of day does not. Despite those risks, the UCLA research found that more than half of students interviewed considered it socially unacceptable to stand up and stretch in the middle of class, and nearly two-thirds felt the same about doing so during smaller discussion sections.

"A cultural change has to take place -- that it's OK to take a stretch break, to stand up during a lecture, to fidget when needed -- it's 'good' for health's sake," Leung said. "My students have an advantage because dance classes naturally involve movement, but we can extend these benefits to any class on campus with something as simple as short stretching breaks -- no dancing required."

Some of the recommendations are simple: Take hourly breaks to stand and stretch during long classes; include more small-group activities that require moving to switch desks; and create more open classrooms with space to walk without squeezing past fellow students and room to install standing desk areas.

To overcome social stigma, the researchers emphasized that professors and instructors will have to take the lead in offering group breaks at specific times rather than suggesting students can get up any time they wish. They also recommended that professors encourage students to get up and move during their breaks; and suggested that university administrators establish policies that call for building more open classrooms and adding features such as adjustable desks.

The research was funded by the Semel Healthy Campus Initiative Center at UCLA, a campuswide effort to make the healthy choice the easy choice, and to promote wellness through education and research. For the study, moderators conducted eight focus-group interviews and guided discussions with 66 UCLA students, roughly half undergraduates and half graduate students. The researchers also interviewed eight faculty members. The researchers looked at how much students and faculty knew about the health risks of sitting, investigated whether the participants could avoid prolonged sitting in class, and gathered ideas for feasible solutions.

"We need to change the way we teach so that we can offer more standing breaks, create opportunities for in-class movement, and even change the built environment so that there's more room for moving around," Cowgill said.

But even though the study found that students and faculty were broadly supportive of making changes, Cowgill said he doubts people will, ahem, stand up against the status quo if there isn't also an effort to raise awareness about the health risks. Social norms and the physical classroom environment are barriers, but awareness is the biggest obstacle.

Cowgill said he was surprised to learn that many of the participants were not aware of the health problems that prolonged sitting can cause, even for people who are otherwise active. "Many people thought they would be fine if they also squeezed in a 30-minute jog, and that's just not what research shows us."

The researchers expect the study will shed light on misconceptions about the health risks of extended sitting, and help faculty and students learn the ways they can work together to stand up and stretch.

https://www.sciencedaily.com/releases/2020/02/200206132339.htm