|
 Researchers used activity trackers to see how much physical activity
children got, then interviewed kids and their parents to assess
whether kids had symptoms of depression.
When kids got more moderate to vigorous physical activity at ages 6
and 8, they were less likely to have symptoms of major depressive
disorder two years later, the study found.
“Our results indicate that increasing physical activity in children
may prevent depression,” said study leader Dr. Tonje Zahl, of the
Norwegian University of Science and Technology in Trondheim.
While plenty of research has documented the potential for exercise
to boost mood and help with depression for adults, less is known
about the ways activity may influence mental health in young
children. Often, depression and other mental health disorders don’t
emerge until adolescence or early adulthood.
The study included a sample of children from Trondheim. Researchers
surveyed parents to assess children’s mental health at age 6, then
did follow-up interviews with parents and kids at age 8 and 10 to
determine whether they had symptoms of depression.
Altogether, they had data on 795 kids at age 6, 699 at age 8 and 702
at age 10.
At ages 6 and 8, children were asked to wear accelerometers to track
their movements for one week, removing the devices only to bathe.
The accelerometers showed that at age 6, kids typically got about
1.19 hours a day of moderate to vigorous physical activity and had
8.58 hours of sedentary time.
At age 8, active time was 1.18 hours a day on average with 9.22
hours of sedentary time.
By age 10, active time dipped to 1.09 hours on a typical day with
9.94 hours of sedentary time.
Researchers assessed kids for nine different symptoms of depression
and found on average, kids had 0.52 symptoms at ages 6 and 10, with
0.46 at age 8.
Higher levels of moderate-to-vigorous physical activity at 6 and 8
predicted fewer symptoms of major depressive disorder two years
later, with every extra hour of such activity linked with a moderate
decrease in symptoms.
The study didn’t find an association between inactivity and symptoms
of depression, however.
One limitation of the study is that symptoms of depression don’t
necessarily mean children would have a clinical diagnosis of
depression, the authors note in Pediatrics.
[to top of second column] |
In fact, only a few children had diagnoses of major depressive
order: 0.3 percent of participants at age six, and 0.4 percent by
age eight.
The study is also observational, and can’t show how any amount of
exercise might cause kids to become depressed.
Even so, there are many possible biological explanations for why
exercise might make depression less likely in kids, said Dr. Gary
Goldfield, a psychology researcher at the University of Ottawa in
Canada who wasn’t involved in the study.
For one thing, exercise releases several chemicals in the brain that
can improve mood or reduce feelings of depression including
endorphins, serotonin and dopamine, Goldfield said. Physical
activity can also lead to lower levels of the stress hormone
cortisol.
“Physical activity can also reduce depression through many
psychosocial processes such as reduced stress, increased social
interaction, improved cognition, learning and academic performance
as well as increased self-esteem, body image and quality of life
which can positively impact mood,” Goldfield added by email.
The study results suggest that children, like adults, can get
lasting benefits from regular exercise, said Dr. Larry Rosen,
professor emeritus of psychology at California State University,
Dominguez Hills.
“The message seems clear,” Rosen, who wasn’t involved in the study,
said by email. “Exercise now keeps you feeling better later.”
SOURCE: http://bit.ly/2j6TCbx Pediatrics, online January 11, 2017
[© 2017 Thomson Reuters. All rights
reserved.] Copyright 2017 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.
 |
