Depression is different from the fluctuations in mood that people experience as a part of normal life. Temporary emotional responses to the challenges of everyday life do not constitute depression.

Likewise, even the feeling of grief resulting from the death of someone close is not itself depression if it does not persist. Depression can, however, be related to bereavement – when depression follows a loss, psychologists call it a “complicated bereavement.”

Depression often results in significant economic and health burdens on society. One factor that contributes to this burden is the challenge in successful treatment of depression. Research indicates that nearly half of patients do not respond to initial treatment and one-third remain depressed even after multiple treatment attempts. While this indicates a need for more effective ways to treat people with depression, many researchers are also examining strategies to prevent depression.

Now, a recent study published in the American Journal of Psychiatry indicates that exercise may also be one way to prevent depression. The researchers who conducted this study found that 1-2 hours of exercise per week is enough to significantly reduce the risk of depression. People who reported no exercise were 44 percent more likely to be depressed in the future compared to those who exercised for 1-2 hours per week.

While 1-2 hours per week may sound like a daunting goal for someone who doesn’t exercise, so it is even more encouraging that the results suggest that as little as 30 minutes of exercise per week may be beneficial. Also, the researchers found that the intensity of the exercise did not impact the preventive effect. So, one 30-minute walk per week may be enough to help prevent depression.

While the results of this study are encouraging, more research in this area is needed. We need to develop effective interventions to increase exercise among persons at risk for depression and we need to understand the biology of how exercise prevents depression. With a greater understanding of these issues, we can hopefully reduce the burden caused by depression.

source: http://www.acsm.org/public-information/acsm-blog/2017/10/10/physical-activity-depression-prevention