Regular exercise protects against future depression
Regardless of intensity, exercising regularly during leisure time is protective against future depression but not anxiety, according to a recent study.
Individuals who underwent regular leisure-time exercise were more likely to have decrease incidence of future depression but not anxiety. This protective effect usually occurred at low levels of exercise and was observed in any intensity.
With the assumption of a causal relationship, the population attributable fraction suggested that 12 percent of future cases of depression could have been prevented if all participants had engaged in at least 1 hour of physical activity weekly after adjustment for confounders.
A small proportion of the protective effect could be explained by the social and physical health benefits of exercise. On the other hand, it appeared that previously proposed biological mechanisms, such as alterations in parasympathetic vagal tone, had no role in explaining the protective effect against depression, according to the authors.
“Relatively modest changes in population levels of exercise may have important public mental health benefits and prevent a substantial number of new cases of depression,” they said.
The present study aimed to determine whether exercise provides protection against new-onset depression and anxiety, the intensity and amount of exercise needed to achieve protection, and the mechanisms that bring about any association.
The authors prospectively followed for 11 years a “healthy” cohort of 33,908 adults, selected based on having no symptoms of common mental disorder or limiting physical health conditions. They collected validated measures of exercise, depression, anxiety and a range of potential confounding and mediating factors.