"When we are down we tend to choose to do things that cheer us up, and when we are up we may take on activities that will tend to bring us down. However, in our current situation with COVID-19, lockdowns and social isolation, our choice of activity is very limited," said study co-author Guy Goodwin, a professor emeritus of psychiatry at the University of Oxford.
Goodwin and his colleagues looked at more than 58,000 people in low-, middle- and high-income countries and compared those with low mood or a history of depression to those with high mood.
The study assessed how people regulate their mood through their choice of everyday activities and found that this ability (mood homeostasis) is impaired in people with low mood and may be absent in people with a history of depression.
One in 5 people will develop major depression in their lifetime, and pandemic lockdown measures could result in even more cases of depression, according to the researchers.
"By training people to increase their own mood homeostasis, how someone naturally regulates their mood via their choices of activities, we might be able to prevent or better treat depression," said study lead author Maxime Taquet, academic foundation doctor at Oxford.
"This is likely to be important at times of lockdown and social isolation when people are more vulnerable to depression and when choices of activities appear restricted," Taquet said in an Oxford news release.
"Our research findings open the door to new opportunities for developing and optimizing treatments for depression and this could potentially be well-adapted to treatments in the form of smartphone apps, made available to a large population which sometimes lack access to existing treatments," he said.
The study was published April 22 in the journal JAMA Psychiatry.