title: Neuropsychiatric Symptoms Predict Functional Status in Alzheimer's Disease.
abstract: BACKGROUND
  Cognitive deficits are presumed to be the primary driver of functional impairment in Alzheimer's disease (AD); however, functional impairment is likely multifactorially determined.
  
  
  OBJECTIVE
  Our objective was to determine the relative contribution of neuropsychiatric symptoms in predicting ratings of functional status.
  
  
  METHODS
  A total of 223 patients received routine neurological and neuropsychological evaluations and met criteria of probable AD dementia based on the McKhann criteria. Demographic, cognitive, and neuropsychiatric variables were entered in a hierarchical linear regression analysis to predict functional status as measured by the Functional Activities Questionnaire (FAQ).
  
  
  RESULTS
  The total model explained 29.7% of the variance (p <  0.001) in FAQ. Importantly, neuropsychiatric variables explained 12.7% of the unique variance, with apathy and sleep as significant contributors.
  
  
  CONCLUSIONS
  Two neuropsychiatric variables, apathy and changes in sleep/nighttime behaviors, predicted ratings of functional status in AD patients independent of age, global cognition, memory and executive function measures, and depressive symptoms. These results highlight the importance of neuropsychiatric symptoms in understanding and potentially treating the functional limitations so prevalent in AD.
authors.affiliation: Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA.
authors.forename: S Christine
authors.initials: SC
authors.lastname: You
authors.affiliation: Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Walsh
authors.affiliation: AbbVie Inc., North Chicago, IL, USA.
authors.forename: Louis A
authors.initials: LA
authors.lastname: Chiodo
authors.affiliation: Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Robin
authors.initials: R
authors.lastname: Ketelle
authors.affiliation: Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Miller
authors.affiliation: Department of Neurology, Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA.
authors.forename: Joel H
authors.initials: JH
authors.lastname: Kramer
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology*; D057565:Apathy; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009460:Neurologic Examination; D009483:Neuropsychological Tests; D011379:Prognosis; D012890:Sleep; D012893:Sleep Wake Disorders / Q000503:physiopathology
keywords: Alzheimer’s disease; apathy; neuropsychology; sleep disorders