a1 Department of Clinical and Biomedical Sciences, Barwon Health, The University of Melbourne, Geelong, Australia
a2 School of Psychology, Deakin University, Geelong, Australia
Background: Regular physical activity is generally associated with psychological well-being, although there are relatively few prospective studies in older adults. We investigated habitual physical activity as a risk factor for de novo depressive and anxiety disorders in older men and women from the general population.
Methods: In this nested case-control study, subjects aged 60 years or more were identified from randomly selected cohorts being followed prospectively in the Geelong Osteoporosis Study. Cases were individuals with incident depressive or anxiety disorders, diagnosed using the Structured Clinical Interview for DSM-IV-TR (SCID-I/NP); controls had no history of these disorders. Habitual physical activity, measured using a validated questionnaire, and other exposures were documented at baseline, approximately four years prior to psychiatric interviews. Those with depressive or anxiety disorders that pre-dated baseline were excluded.
Results: Of 547 eligible subjects, 14 developed de novo depressive or anxiety disorders and were classified as cases; 533 controls remained free of disease. Physical activity was protective against the likelihood of depressive and anxiety disorders; OR = 0.55 (95% CI 0.32–0.94), p = 0.03; each standard deviation increase in the transformed physical activity score was associated with an approximate halving in the likelihood of developing depressive or anxiety disorders. Leisure-time physical activity contributed substantially to the overall physical activity score. Age, gender, smoking, alcohol consumption, weight and socioeconomic status did not substantially confound the association.
Conclusion: This study provides evidence consistent with the notion that higher levels of habitual physical activity are protective against the subsequent risk of development of de novo depressive and anxiety disorders.
(Received July 15 2010)
(Revised August 03 2010)
(Revised August 06 2010)
(Accepted August 08 2010)
(Online publication September 24 2010)
c1 Correspondence should be addressed to: Associate Professor Julie A. Pasco, Epidemiology and Biostatistics Unit, Department of Clinical and Biomedical Sciences: Barwon Health, The University of Melbourne, PO Box 281, Geelong 3220, Australia. Phone: +61 3 5226 7393; Fax: +61 3 5246 5165. Email: email@example.com.