Exercise can reduce risk for depression, research shows

Jan. 24 (UPI) -- New research suggests that people who get more physical activity have lower levels of depression.

People who wore motion-detecting sensors called accelerometers on their wrists to monitor their exercise fought off depression better than people who self-reported their physical activity, according to findings published Wednesday in JAMA Psychiatry.

"Using genetic data, we found evidence that higher levels of physical activity may causally reduce risk for depression," Karmel Choi, a researcher of the Psychiatric and Neurodevelopmental Genetics Unit in the MGH Center for Genomic Medicine and study lead author, said in a news release. "Knowing whether an associated factor actually causes an outcome is important, because we want to invest in preventive strategies that really work."

The self-reporters may have been unable to stave off depression because they misreported their actual physical activity to save face or due to bad memories, suggesting they didn't work out as much as the monitored group.

"On average, doing more physical activity appears to protect against developing depression," Choi said. "Any activity appears to be better than none. Our rough calculations suggest that replacing sitting with 15 minutes of a heart-pumping activity like running, or with an hour of moderately vigorous activity, is enough to produce the average increase in accelerometer data that was linked to a lower depression risk."

Now the researchers will see what genetic differences may play a factor in the connection between exercise and lower depression levels.

Choi said more work is required to determine whether and how much exercise can help different groups of patients, and how to tailor prescriptions of physical activity for each patient.

"Of course, it's one thing to know that physical activity could be beneficial for preventing depression," Choi said. "It's another to actually get people to be physically active."