Major depressive disorder is a common mental health condition around the world. It is shaped by childhood experiences, lifestyle choices, and genetics. A new study shows that staying physically active can help reduce the impact of genetic risk on how severe a person’s depression symptoms are.
Researchers at the University of Texas at San Antonio published the study in Nature Mental Health. They analyzed long-term data from fitness trackers, health records, and genetic profiles for 23,517 adults in the National Institutes of Health’s All of Us Research Program.
Lead author Qiliang He explained that earlier studies often used short-term or self-reported exercise data, which can be unreliable. By using Fitbit records over about 1.6 years per person, the team got a much clearer view of daily habits, including step counts and time spent in moderate or vigorous activity.
To study how biology and behavior are connected, the scientists calculated polygenic risk scores to estimate each person’s genetic risk for depression. As expected, people with higher genetic risk were more likely to be diagnosed with depression.
But when the researchers looked at how severe symptoms were, they found something important. People with the highest genetic risk for depression benefited the most from regular physical activity. Those who stayed active had much less severe symptoms than less active people, no matter their genetic risk.
Although this study is observational, the team hopes that this kind of wearable data will help lead to more personalized medicine.
In the future, doctors might be able to recommend specific types and amounts of exercise based on a person’s genetic profile. The researchers also plan to see if similar lifestyle changes can help protect against severe anxiety disorders.