Physical activity may reduce depression symptoms

The study found that physical activity can improve mood afterward.Pilin_Petunyia / iStock / Thinkstock

Physical activity can help improve your health and quality of life. Not getting enough physical activity can increase your risk for diabetes, heart disease, cancers, and mental health disorders.

Current theories about depression suggest that sleep problems, a lack of energy, and physical inactivity can result from a depressed mood. To investigate the relationship between mood disorders and these factors, a team led by Dr. Kathleen Merikangas at NIH’s National Institute of Mental Health (NIMH) and Dr. Vadim Zipunnikov at John Hopkins University collected real-time measures of physical activity and sleep.

The scientists enrolled 54 adults with bipolar disorder, which involves episodes of depression; 91 with major depressive disorder; and 97 with no history of mood disorders. The study was supported in part by NIMH. Results were published online on December 12, 2018, in JAMA Psychiatry.

For two weeks, the researchers monitored participants’ physical activity using mobile monitoring devices worn around the wrist. They collected minute-by-minute physical activity data and used this information to estimate how long participants slept. Participants also completed diary entries of their mood and energy levels four times a day for two weeks. At each assessment, participants were asked to rate the degree to which they felt “very happy” to “very sad” and “very tired” to “very energetic.”

The researchers found that physical activity affected the participants’ mood afterward, but mood didn’t affect the amount of physical activity they engaged in later. Physical activity also affected how energetic participants felt and how long they slept. These relationships went both ways: energy levels and sleep also affected how much physical activity participants later engaged in.

Among those with bipolar disorder, 25 had a more severe form called bipolar I. The relationships among physical activity, sleep, mood, and energy were substantially stronger in people with this disorder than in other participants, suggesting that people with bipolar-I disorder may react more strongly to changes in these areas of day-to-day life.

The results suggest that physical activity may play a central role in mood regulation, and thus might be an effective target for interventions to change mood states.

“The research team and I are currently conducting additional studies to understand these complex interactions better—repeating the assessments to study the generalizability of these findings over longer periods of time,” Merikangas says.