title: Neuropsychiatric disturbances in Parkinson's disease clusters in five groups with different prevalence of dementia.
abstract: OBJECTIVE
  To investigate the inter-relationship of neuropsychiatric disturbances in Parkinson's disease (PD) by cluster analysis and describe the properties of the clusters.
  
  
  METHODS
  A total of 139 patients were assessed using the neuropsychiatric inventory (NPI). A cluster-analysis was used to investigate the inter-relationship of NPI items. The clusters were profiled regarding dementia (PDD) and major depression.
  
  
  RESULTS
  A total of 39 patients showed no neuropsychiatric symptoms. The remaining 100 patients (43% PDD) were divided in to five clusters. The largest group (42, 31% PDD) showed symptoms of mild depression, followed by a group (29, 79.3% PDD) with hallucinations and mild other symptoms. The third group (14, 7.1% PDD) had sleep disturbances exclusively. The fourth group (8, 25% PDD) showed apathy, anxiety and depression. The smallest group (7, 57.1% PDD) had high scores on several NPI items.
  
  
  CONCLUSIONS
  Our PD sample can be divided in to clusters based on the NPI, with different prevalence of dementia and depression.
authors.affiliation: Section of Geriatric Psychiatry, Stavanger University Hospital, Helse Stavanger, Norway. kobr@sir.no
authors.forename: K
authors.initials: K
authors.lastname: Bronnick
authors.forename: D
authors.initials: D
authors.lastname: Aarsland
authors.forename: J P
authors.initials: JP
authors.lastname: Larsen
mesh_terms: D000328:Adult; D000368:Aged; D016000:Cluster Analysis; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology*; D003704:Dementia / Q000175:diagnosis* / Q000453:epidemiology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis* / Q000209:etiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000453:epidemiology*; D015995:Prevalence; D011570:Psychiatry / Q000379:methods*; D011795:Surveys and Questionnaires