Above-moderate physical activity reduces both incident and persistent late-life depression in rural Koreans.

Objective: To investigate the natural course of depressive symptoms among community-dwelling elderly over 5 years. Rates and correlates of the incidence and the persistence of late-life depression were examined.

Methods: A total of 701 elderly people 65 years of age or older without dementia at baseline were included in this study. The association between categorically defined late-life depression (score of ≥ 8 on the Korean version of the Geriatric Depression Scale-Short Form) and possible lifestyle and clinical risk factors, including physical activity assessed with a modified Korean version of the International Physical Activity Questionnaire (IPAQ) and transformed into weekly Metabolic Equivalent Task (MET) values, was longitudinally investigated using multiple logistic regression analyses. Adjustment was done with sociodemographic variables, chronic medical illnesses, and cognitive dysfunction.

Results: During the 5-year follow-up, 74 (26.5%) of the non-depressed elderly developed depression, whereas 30 (49.2%) of the depressed elderly experienced persistent depression. Above-moderate baseline physical activity was independently associated with decreased incidence and persistence rates of late-life depression (adjusted odds ratio (AOR) = 0.44, 95% confidence interval (CI) = 0.22-0.85; AOR = 0.17, 95% CI = 0.03-0.92, respectively), whereas mild physical activity was not. Conversely, poorer executive function also predicted 5-year incident depression (AOR = 0.93, 95% CI = 0.89-0.98) but not persistent depression.

Conclusion: This study suggests that a minimum of moderate physical activity is related to both emergent and persistent depression in elderly individuals. Research with an extended follow-up period and a shorter inter-assessment interval is needed to confirm this result.