title: Cognitive and behavioral determinants of psychotic symptoms in Alzheimer's disease.
abstract: OBJECTIVE
  To investigate the relationship between psychotic symptoms and cognitive impairment in Alzheimer's disease (AD).
  
  
  METHODS
  A total of 108 subjects affected by AD were subdivided into subjects without delusions (ND), subjects with paranoid delusions (PD), subjects with delusional misidentifications (DM), subjects with both DM and PD (DM+PD), subjects with visual hallucinations (v-HALL), and subjects without visual hallucinations (N-HALL).
  
  
  RESULTS
  PD and ND subjects performed similarly on neuropsychological tests, while DM patients performed significantly worse than PD and ND patients. v-HALL patients performed worse than N-HALL patients on memory, visuospatial, and executive functions. As for behavioral features, DM and v-HALL subjects reported higher scores on the abnormal motor behavior subscale of the neuropsychiatric inventory (NPI); PD subjects reported higher scores on the disinhibition subscale of the NPI. The severity of PD was predicted by the severity of disinhibition (B = 0.514; p = 0.016) but not by neuropsychological performances. The severity of DM was predicted by age (B = 0.099; p = 0.048) and MMSE (B = -0.233; p = 0.001). The severity of v-HALL was predicted by age (B = 0.052; p = 0.037) and scores on an immediate visual memory task (B = -0.135; p = 0.007).
  
  
  CONCLUSIONS
  The occurrence of PD may require the relative sparing of cognitive functions and be favored by frontal lobe dysfunction, while DM is associated with the overall level of cognitive impairment. Finally, v-HALL are associated with the impairment of visuospatial abilities.
authors.affiliation: Research Center for Neuropsychology, Institute of Neurology, Catholic University, Rome, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Quaranta
authors.forename: Maria Gabriella
authors.initials: MG
authors.lastname: Vita
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bizzarro
authors.forename: Carlo
authors.initials: C
authors.lastname: Masullo
authors.forename: Chiara
authors.initials: C
authors.lastname: Piccininni
authors.forename: Guido
authors.initials: G
authors.lastname: Gainotti
authors.forename: Camillo
authors.initials: C
authors.lastname: Marra
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology / Q000523:psychology*; D003072:Cognition Disorders / Q000523:psychology; D003430:Cross-Sectional Studies; D003702:Delusions / Q000209:etiology*; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006212:Hallucinations / Q000209:etiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D009483:Neuropsychological Tests; D011618:Psychotic Disorders / Q000209:etiology*; D012720:Severity of Illness Index