title: Longitudinal association between habitual physical activity and depressive symptoms in older people.
abstract: OBJECTIVE
  Prevention of depressive symptoms is an essential issue with regard to the promotion of healthy lifestyles in older people. To date, few studies have examined the relation between fluctuations in physical activity and depression among older individuals. We thus conducted a longitudinal survey of older adults to examine the effect of long-term fluctuating physical activity on the incidence of depressive symptoms.
  
  
  METHODS
  A 3-year prospective cohort study was performed in a community-based environment. A total of 680 individuals (291 men and 389 women) aged 65 years and over at the baseline assessment participated. The 15-item Geriatric Depression Scale was used to assess depressive symptoms, with scores of ≥6 indicative of depression. Participants were categorized into the following four groups based on change in physical activity status between 2002 and 2003: sedentary, cessation, initiation, and maintenance.
  
  
  RESULTS
  The incidence of depressive symptoms was 16.9% (16.8% in men and 17.0% in women) at the 3-year follow up (in 2006). Multiple logistic regression analyses showed that physical activity maintenance (odds ratio, 0.50; 95% confidence interval, 0.30-0.83) only reduced the incidence of depressive symptoms at the 3-year follow up after adjusting for confounding variables.
  
  
  CONCLUSIONS
  Continuous physical activity may be a valuable and simple way to prevent depressive symptoms in community-dwelling older people. Therefore, it is necessary to implement interventions that teach older adults how to integrate physical activity into their daily lives.
authors.affiliation: Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yoshida
authors.affiliation: Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.|Department of Public Health, Fukushima Medical University School of Medicine, Fukushima, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Iwasa
authors.affiliation: University of Human Arts and Sciences, Saitama, Japan.
authors.forename: Shu
authors.initials: S
authors.lastname: Kumagai
authors.affiliation: National Center for Geriatrics and Gerontology, Aichi, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Shuichi
authors.initials: S
authors.lastname: Awata
authors.affiliation: Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
authors.forename: Hideyo
authors.initials: H
authors.lastname: Yoshida
mesh_terms: D000368:Aged; D000375:Aging / Q000523:psychology*; D003863:Depression / Q000453:epidemiology* / Q000517:prevention & control; D015444:Exercise; D005260:Female; D006184:Habits; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D009043:Motor Activity; D011446:Prospective Studies
keywords: community-dwelling older adults; depression symptoms; longitudinal study; physical activity