Bottom Line: On average, more frequent physical activity was associated with fewer depressive symptoms for adults between the ages of 23 and 50 years, while a higher level of depressive symptoms was linked to less frequent physical activity.
Authors: Snehal M. Pinto Pereira, Ph.D., of the University College London, England, and colleagues.
Background: Physical activity can reduce the risk of death, stroke and some cancers, and some studies suggest activity can also lower the risk for depressive symptoms. But the evidence on activity and depression has limitations.
How the Study Was Conducted: The authors examined whether depressive symptoms are concurrent with physical activity levels, as well as whether activity influences the level of symptoms and if the level of symptoms influences activity. The study used data from about 11,000 participants in a 1958 British birth cohort where participants were followed to age 50 years. Information on depressive symptoms or physical activity frequency was available at 23, 33, 42, or 50 years of age.
Results: More activity frequency predicted a lower number of depressive symptoms (per higher frequency of activity per week, symptoms were lower by 0.06 at age 50 years). Among those inactive at any age, increasing activity from 0 to 3 times per week five years later reduced the odds of depression by 19 percent. Higher levels of depressive symptoms were related to less frequent physical activity. Across all ages, those participants with depression were less active by 0.27 times per week. For example, among 23 year old participants who were not depressed, their average increase in activity five years later was 0.63 times per week but 0.36 times per week for those with depression.
Discussion: "Findings suggest that activity may alleviate depressive symptoms in the general population and, in turn, depressive symptoms in early adulthood may be a barrier to activity."