Physical activity and common mental disorders
S. B Harvey,
Previous studies have suggested that physical activity may have
antidepressant and/or anti-anxiety effects.
To examine the bidirectional relationship between physical activity and
common mental disorders and establish the importance of context, type and
intensity of activity undertaken.
A clinical examination of 40 401 residents of Norway was undertaken.
Participants answered questions relating to the frequency and intensity of
both leisure-time and workplace activity. Depression and anxiety were measured
using the Hospital Anxiety and Depression Scale (HADS). Biological and social
data were also collected.
There was an inverse relationship between the amount of leisure-time
physical activity and case-level symptoms of depression. This cross-sectional
association was only present with leisure-time (as opposed to workplace)
activity and was not dependent on the intensity of activities undertaken.
Higher levels of social support and social engagement were important in
explaining the relationship between leisure activity and depression.
Biological changes such as alterations to parasympathetic vagal tone (resting
pulse) and changes to metabolic markers had a less important role.
Individuals who engage in regular leisure-time activity of any intensity
are less likely to have symptoms of depression. The context and social
benefits of exercise are important in explaining this relationship.