title: The relationship between depression and frailty syndrome: a systematic review.
abstract: OBJECTIVE
  Frailty is a geriatric syndrome characterised by the clinical presentation of identifiable physical alterations such as loss of muscle mass and strength, energy and exercise tolerance, and decreased physiological reserve. Frailty and depressive symptoms are common issues facing older adults and may be associated. It is not clear if the depression facilitates the appearance of frailty syndrome or vice versa or these two coexist independently in the same individuals.
  
  
  METHODS
  We performed searches in several databases (Embase, PubMed, CINAHL, Scopus, and PsycINFO) papers published between November 2003 to February 2014 about frailty syndrome and depression in people aged 65 and older published and the reference lists of from the articles retrieved were pearled in order to identify any which may have been missed in the initial search. Two independent reviewers extracted descriptive information on the prevalence and co-occurrence of frailty and depression in older individuals and of frailty criteria among depressed patients.
  
  
  RESULTS
  Depression and frailty occur in a significant proportion of frail older individuals. Common pathophysiological alterations and biomarkers in the two syndromes have been recently described.
  
  
  CONCLUSIONS
  Studies on the causal relationship between the two syndromes are clearly necessary in the future.
authors.affiliation: a Department of Nursing , University of Valencia , Valencia , Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Buigues
authors.forename: Celia
authors.initials: C
authors.lastname: Padilla-Sánchez
authors.forename: Julio Fernández
authors.initials: JF
authors.lastname: Garrido
authors.forename: Rut
authors.initials: R
authors.lastname: Navarro-Martínez
authors.forename: Vicente
authors.initials: V
authors.lastname: Ruiz-Ros
authors.forename: Omar
authors.initials: O
authors.lastname: Cauli
mesh_terms: D000368:Aged; D015897:Comorbidity; D003863:Depression / Q000453:epidemiology*; D016330:Frail Elderly / Q000523:psychology; D006801:Humans
keywords: biological markers; depression; mental health