title: The longitudinal effect of depression on functional limitations and disability in older adults: an eight-wave prospective community-based study.
abstract: BACKGROUND
  The temporal relationship between depression and adverse functional outcomes in older adults is ambiguous. In the present eight-wave prospective community-based study, the longitudinal effect of depression on functional limitations and disability (in terms of disability days and bed days) was studied, thereby taking into account the role of chronic physical diseases.
  
  
  METHODS
  The study is based on a sample which at the outset consisted of 325 non-depressed and 327 depressed persons (55-85 years) drawn from a larger random community based sample in the Netherlands. Generalized estimating equations time-lag models were used to examine the longitudinal relation between depression and both functional limitations and disability.
  
  
  RESULTS
  Functional limitations were very persistent over time, whereas disability days and bed days were more fluctuating functional outcomes. Only in the presence of chronic physical diseases, there was a significant longitudinal association between depression at the previous measurement and functional limitations, disability days and bed days at the next measurement. The effect on functional limitations was small, which was probably partly due to their persistent nature.
  
  
  CONCLUSIONS
  The finding of a longitudinal relationship between depression and functional outcomes in older adults with a compromised health status provides a rationale for treatment of chronic physical diseases as well as depression in depressed chronically ill elderly, in order to prevent a spiralling decline in psychological and physical health.
authors.affiliation: Department of Psychiatry and the Institute for Research in Extramural Medicine (EMGO), Free University, Amsterdam, The Netherlands.
authors.forename: S W
authors.initials: SW
authors.lastname: Geerlings
authors.forename: A T
authors.initials: AT
authors.lastname: Beekman
authors.forename: D J
authors.initials: DJ
authors.lastname: Deeg
authors.forename: J W
authors.initials: JW
authors.lastname: Twisk
authors.forename: W
authors.initials: W
authors.lastname: Van Tilburg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003156:Community Mental Health Services; D003865:Major Depressive Disorder / Q000453:epidemiology* / Q000523:psychology*; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012720:Severity of Illness Index; D017678:Sex Distribution