title: Factor structure of the Geriatric Depression Scale and relationships with cognition and function in Alzheimer's disease.
abstract: OBJECTIVE
  No study to date has systematically explored whether the Geriatric Depression Scale (GDS) measures symptoms of apathy and dysphoria in patients with Alzheimer's disease (AD) or related these constructs to cognitive and functional status.
  
  
  METHODS
  Exploratory factor analysis (EFA) was used to identify factors of the GDS in a sample of 569 patients with probable AD. Two-way ANOVAs were used to determine the relationship of apathy and dysphoria to neuropsychological and functional measures.
  
  
  RESULTS
  The EFA yielded four factors associated with apathy, dysphoria, social withdrawal and cognitive impairment. Apathy was associated with greater impairments in verbal memory, motor speed, and functional abilities.
  
  
  CONCLUSIONS
  Apathy, but not dysphoria, was associated with some cognitive and functional variables. Results suggest that the GDS may be used as a screening measure for symptoms of apathy in AD.
authors.affiliation: Department of Psychology, University of Houston, Houston, TX 77204-5502, USA. whitney.havins@gmail.com
authors.forename: Whitney N
authors.initials: WN
authors.lastname: Havins
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Massman
authors.forename: Rachelle
authors.initials: R
authors.lastname: Doody
mesh_terms: D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications* / Q000523:psychology*; D057565:Apathy; D001288:Attention / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000523:psychology; D003863:Depression / Q000209:etiology* / Q000523:psychology*; D056344:Executive Function / Q000502:physiology; D005260:Female; D006801:Humans; D007802:Language; D008297:Male; D008568:Memory / Q000502:physiology; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011597:Psychomotor Performance / Q000502:physiology; D012919:Social Behavior