title: The psychosis of schizophrenia: prevalence, response to atypical antipsychotics, and prediction of outcome.
abstract: BACKGROUND
  Psychosis is a defining feature of schizophrenia consisting of formal thought disorder, delusions, and hallucinations. Although psychosis is present in the majority of patients with schizophrenia, the prevalence, responsiveness to atypical antipsychotic drug therapy, and prediction of outcome of individual psychotic symptoms in a population of well-diagnosed patients with schizophrenia have not been conclusively established.
  
  
  METHODS
  This paper examined the prevalence, responsiveness to the atypical antipsychotic olanzapine, and relationship to outcome of individual psychotic symptoms using data from a previously reported large multicenter, double-blind clinical trial of olanzapine (mean daily dose at endpoint = 13.6 +/- 6.9 mg/day).
  
  
  RESULTS
  The most frequently reported psychotic symptoms at baseline were delusions (65%), conceptual disorganization (50%), and hallucinations (52%), and the majority of patients (68%) experienced from one to three symptoms. Additionally, with olanzapine treatment there were significant improvements (p < .001) in baseline to endpoint Positive and Negative Symptom Scale (PANSS) psychotic item scores, with the largest effect sizes observed for hallucinatory behavior, unusual thought content, suspiciousness/persecution, and delusions. During the acute phase of the trial, quality of life was correlated significantly with baseline conceptual disorganization (p = .038) and unusual thought content (p = .023), and time spent in the hospital was correlated with unusual thought content (p = .005).
  
  
  CONCLUSIONS
  The implications of these for the clinical management of schizophrenia are discussed.
authors.affiliation: Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, Indiana 46285, USA.
authors.forename: A
authors.initials: A
authors.lastname: Breier
authors.forename: P H
authors.initials: PH
authors.lastname: Berg
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use*; D001569:Benzodiazepines; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D000077152:Olanzapine; D010890:Pirenzepine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D015995:Prevalence; D011379:Prognosis; D011618:Psychotic Disorders / Q000188:drug therapy* / Q000453:epidemiology* / Q000523:psychology; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D001569:Benzodiazepines; D010890:Pirenzepine; D000077152:Olanzapine