title: Four components describe behavioral symptoms in 1,120 individuals with late-onset Alzheimer's disease.
abstract: OBJECTIVE
  To investigate behavioral components of Alzheimer's disease (AD) and to analyze behavioral components in relation to disease severity, apolipoprotein E genotype (APOE), sex, years of education, age at onset, and cognitive impairment.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Data were collected from community-dwelling individuals and those residing in nursing homes.
  
  
  METHODS
  A total of 1,120 individuals meeting National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association criteria for late-onset probable AD.
  
  
  METHODS
  Behavioral symptoms were assessed using the Neuropsychiatric Inventory. First-order polychoric correlations, controlling for disease severity, between the 12 symptom domain scores were estimated, and the resulting matrix underwent principal components analysis.
  
  
  RESULTS
  Four interpretable components were identified: behavioral dyscontrol (euphoria, disinhibition, aberrant motor behavior, and sleep and appetite disturbances), psychosis (delusions and hallucinations), mood (depression, anxiety, and apathy), and agitation (aggression and irritability). Scores on the four components were associated with severity of cognitive impairment. Higher behavioral dysfunction, agitation, and mood component scores were associated with lower age at onset. Behavioral dysfunction and mood component scores were associated with sex. None of the components were associated with age at assessment, years of education, or number of APOE epsilon4 alleles.
  
  
  CONCLUSIONS
  Four behavioral components were identified that were comparable with those observed previously. Future analysis of these components will strengthen understanding of the underlying pathology of behavioral symptoms and AD.
authors.affiliation: Department of Psychological Medicine, Cardiff University School of Medicine, Heath Park, Cardiff, United Kingdom.
authors.forename: Paul
authors.initials: P
authors.lastname: Hollingworth
authors.forename: Marian L
authors.initials: ML
authors.lastname: Hamshere
authors.forename: Valentina
authors.initials: V
authors.lastname: Moskvina
authors.forename: Kimberley
authors.initials: K
authors.lastname: Dowzell
authors.forename: Pamela J
authors.initials: PJ
authors.lastname: Moore
authors.forename: Catherine
authors.initials: C
authors.lastname: Foy
authors.forename: Nicola
authors.initials: N
authors.lastname: Archer
authors.forename: Aoibhinn
authors.initials: A
authors.lastname: Lynch
authors.forename: Simon
authors.initials: S
authors.lastname: Lovestone
authors.forename: Carol
authors.initials: C
authors.lastname: Brayne
authors.forename: David C
authors.initials: DC
authors.lastname: Rubinsztein
authors.forename: Brian
authors.initials: B
authors.lastname: Lawlor
authors.forename: Mike
authors.initials: M
authors.lastname: Gill
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Owen
authors.forename: Julie
authors.initials: J
authors.lastname: Williams
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology / Q000235:genetics / Q000523:psychology*; D001057:Apolipoproteins E / Q000235:genetics; D001526:Behavioral Symptoms / Q000175:diagnosis / Q000209:etiology*; D003072:Cognition Disorders / Q000209:etiology; D003430:Cross-Sectional Studies; D004522:Educational Status; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012720:Severity of Illness Index; D012737:Sex Factors
chemical_list: D001057:Apolipoproteins E