The idea that exercise may confer both physical and psychological benefits on those who engage in it on a regular basis is hardly new and has been extensively covered in scientific literature.
Now, however, a new study conducted by Harvard researchers at the Massachusetts General Hospital (MGH) shows that even small amounts of daily exercise can significantly lower the risk of a new episode of depression, even in those at high genetic risk.
In the study, the authors drew on genomic and electronic health record data from almost 8,000 participants in the Partners Healthcare Biobank, and identified those who have received depression diagnoses over the next two years based on millions of data points available to them.
Furthermore, by combining information across the entire genome, the research team had also determined each participant’s genetic risk score for major depressive disorder (MDD) and correlated that with their self-reported habits related to exercise.
The results showed that physical activity was effective at slashing the risk of depression across all risk categories, and – at higher levels – was beneficial even in people who were the most likely to be diagnosed with MDD based on their genetic score.
“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,” said Karmel Choi of MGH and the Harvard T.H. Chan School of Public Health, the lead author of the study.
On average, each four-hour block of additional exercise per week – or about 35 minutes per day – reduced the chances of a new episode of depression by about 17 per cent. Both high- and low-intensity exercise was found to be roughly as effective.
Choi is optimistic about using real-world healthcare data and genomics to reduce the burden of mental illness as there are likely many complex and varied factors that come into play to determined one’s level of resilience, or else susceptibility to mental disorders.
The study was published in the journal Depression and Anxiety.