title: [Psychosis in Parkinson's disease].
abstract: BACKGROUND
  Psychosis is common in Parkinson's disease, and occurs with increasing frequency as the disease progresses. Assessment and treatment are often complicated and involve several clinical specialists in addition to the general practitioner. We describe the prevalence, form, causes and treatment of psychosis in Parkinson's disease.
  
  
  METHODS
  The article is based on a literature search in PubMed for controlled pharmacological treatment studies and a discretionary selection of articles based on the authors' clinical and research experience.
  
  
  RESULTS
  About 1 % of patients with newly diagnosed Parkinson's disease have psychotic symptoms. In later stages, complicated by dementia, these symptoms occur in about half of the patients. A false sense of presence, optical illusions and visual hallucinations occur most frequently, but delusions and hallucinations involving other senses have been reported. Various theories to explain the underlying etiology and pathology are explored. A further medical assessment is recommended when psychotic symptoms occur. Clozapine is still the only antipsychotic drug documented effective against psychotic symptoms in Parkinson's disease.
  
  
  CONCLUSIONS
  The prevalence of psychotic symptoms in various stages of Parkinson''s disease has been thoroughly documented. Non-pharmacological treatment is often effective, but the documentation is inadequate. Pharmacological treatment with clozapine has proved effective against psychosis in Parkinson's disease, but new drugs that are easier to administer are needed.
authors.affiliation: Seksjon for alderspsykiatri, Klinikk for psykisk helsevern, Haugesund sykehus, Norway. arvid.rongve@helse-fonna.no
authors.forename: Arvid
authors.initials: A
authors.lastname: Rongve
authors.forename: Eirik
authors.initials: E
authors.lastname: Auning
authors.forename: Uwe
authors.initials: U
authors.lastname: Ehrt
authors.forename: Dag
authors.initials: D
authors.lastname: Arsland
mesh_terms: D014150:Antipsychotic Agents / Q000627:therapeutic use; D006801:Humans; D010300:Parkinson Disease / Q000150:complications* / Q000188:drug therapy / Q000523:psychology; D011618:Psychotic Disorders / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology* / Q000628:therapy
chemical_list: D014150:Antipsychotic Agents