People who engage in at least several hours of exercise per week are less likely to be diagnosed with a new episode of depression, even in the face of high genetic risk for the disorder, according to a new study at Massachusetts General Hospital (MGH).
“Our findings strongly suggest that, when it comes to depression, genes are not destiny and that being physically active has the potential to neutralize the added risk of future episodes in individuals who are genetically vulnerable,” says Karmel Choi, PhD, of MGH and the Harvard T.H. Chan School of Public Health, and lead author of the study.
“On average, about 35 additional minutes of physical activity each day may help people to reduce their risk and protect against future depression episodes.”
Drawing on health recordsfrom nearly 8,000 participants in the Partners Healthcare Biobank, the study is the first to show how physical activity can influence depression despite genetic risk.
The researchers tracked patients who had completed a survey about their lifestyle habits (including physical activity) when they enrolled in the Biobank. The team analyzed millions of electronic health record data points over the next two years and identified people who received diagnoses related to depression.
They also calculated genetic risk scores for each participant, combining information across the entire genome into a single score that reflects a person’s inherited risk for depression.
The results show that people with higher genetic risk were more likely to be diagnosed with depression over the next two years. Significantly, however, those who were more physically active at baseline were less likely to develop depression, even after accounting for genetic risk.
In fact, greater levels of physical activity were protective for people even with the highest genetic risk scores for depression.
The findings show that both high-intensity forms of activity, such as aerobic exercise, dance and exercise machines, and lower-intensity forms, including yoga and stretching, were linked to a reduced risk of depression.
Overall, individuals could see a 17 percent reduction in odds of a new episode of depression for each added four-hour block of activity per week.
“In general, our field has been lacking actionable ways of preventing depression and other mental health conditions,” said senior author Jordan Smoller, M.D. “I think this research shows the value of real-world health care data and genomics to provide answers that can help us to reduce the burden of these diseases.”
Beyond physical activity, the MGH team continues to leverage the Partners Biobank and other large-scale studies to explore modifiable ways that individuals might reduce their risk of depression.
“We provide promising evidence that primary care and mental health providers can use to counsel and make recommendations to patients that here is something meaningful they can do to lower their risk even if they have a family history of depression,” Choi said.
