BOSTON — Exercise may be just as beneficial for the mind as it is for the body. Increasing physical activity levels can significantly reduce one’s chances of developing depression, even for those genetically predisposed to the mental condition. That was the main finding of a study by researchers at Massachusetts General Hospital (MGH).
According to the study, individuals who spent several hours per week exercising were less likely to be diagnosed with a new depressive episode. The results held true for those who also had a high genetic risk for the disorder.
“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 Dr. Karmel Choi, of the Harvard T.H. Chan School of Public Health, in a media release. “On average, about 35 additional minutes of physical activity each day may help people to reduce their risk and protect against future depression episodes.”
Researchers examined health data taken from about 8,000 participants in the Partners Healthcare Biobank, a long-term research project focused on how genes influence health. Participants completed surveys about their lifestyle habits, including exercise, when they initially enrolled in the project. Then, researchers used millions of electronic health record data points to identify studied participants who had received diagnoses related to depression and depressive episodes.
According to the team, this study is the first to prove how physical activity can curb depression in spite of genetic predisposition.
To calculate genetic risk, the researchers combined information from across the entire genome into an index score that reflected each individual’s inherited risk for depression.
Dr. Choi’s team found that people with a higher genetic risk were more likely to be diagnosed with depression over the next two years. However, those who reported being more physically active were less likely to develop the condition, even after accounting for genetic factors. Similarly, higher levels of physical activity were found to be protective for even those with the highest genetic risk indicators for depression.
Both high-intensity activities, such as running and other aerobic exercises, and low-intensity activities like yoga, were identified as successful in lowering the odds of a depression diagnosis. By the authors’ calculations, individuals can reduce their risk of a new depressive episode by 17% for each additional four-hour physical activity block per week.
“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,” says Choi.
“In general our field has been lacking actionable ways of preventing depression and other mental health conditions. I think this research shows the value of real-world healthcare data and genomics to provide answers that can help us to reduce the burden of these diseases,” adds senior author Dr. Jordan Smoller.
The study is published in the scientific journal Depression and Anxiety.