title: [Frailty; a fragile concept].
abstract: BACKGROUND
  Frailty can be regarded as a condition in which the reserve capacity of various physical systems has sunk to a critical low, at which point minor disturbances can develop into serious health problems.
  
  
  OBJECTIVE
  To review the various operationalisations of the concept of frailty and describe the relationship between frailty and psychopathology.
  
  
  METHODS
  We searched the literature up to October 2010 using PubMed, PsycINFO and CINAHL.
  
  
  RESULTS
  We found 35 operationalisations of the concept of frailty; 4 single measurements as a proxy for frailty (e.g. muscle strength), 18 syndrome diagnoses which can be subdivided into single (n = 5) and multiple syndrome diagnoses (n = 13) and 13 dimensional operationalisations for which measurement instruments were used. Only 6 studies reported the relationship between frailty and psychopathology. The studies revealed an association between depression and psychopathology. An important finding was the association between depression and frailty, but the direction of the association is unknown.
  
  
  CONCLUSIONS
  No consensus has been reached regarding the operationalisation of the concept of frailty. For the purpose of gerontopsychiatric research we recommend the inclusion of a syndrome diagnosis based on physical criteria (physical frailty) because this should make it possible to unravel the relationship between psychopathology and underlying ageing mechanisms.
authors.affiliation: Psychiatrie, Nijmegen. r.collard@psy.umcn.nl
authors.forename: R M
authors.initials: RM
authors.lastname: Collard
authors.forename: R C
authors.initials: RC
authors.lastname: Oude Voshaar
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology / Q000502:physiology* / Q000523:psychology*; D016330:Frail Elderly / Q000523:psychology*; D005852:Geriatric Psychiatry; D006801:Humans; D013577:Syndrome