title: Diagnostic stability four years after a first episode of psychosis.
abstract: OBJECTIVE
  The objective of this study was to determine the stability of a diagnosis of psychosis four years after the first-episode diagnosis.
  
  
  METHODS
  The study was a prospective four-year follow-up study (1995 to 1999) of 147 patients with schizophrenia, affective disorder, and other psychoses who presented with a first episode of psychosis in an epidemiologic catchment area in Ireland. All diagnoses were made on the basis of the Structured Clinical Interview for DSM-IV.
  
  
  RESULTS
  One quarter of the patients evidenced a change in diagnosis at follow-up. The most common change was to a diagnosis of schizophrenia. The positive predictive values of schizophrenia and bipolar affective disorder were 97 percent and 80 percent, respectively. Fewer years spent in education, lower levels of initial psychopathology, and presence of comorbid alcohol or substance abuse were associated with change in diagnosis at follow-up.
  
  
  CONCLUSIONS
  Among the diagnoses studied, schizophrenia was the most stable diagnosis after four years. The greatest instability occurred in the categories of drug-induced psychosis and psychosis not otherwise specified.
authors.affiliation: Stanley Research Unit, Cluain Mhuire Family Centre, Newtownpark Avenue, Blackrock, County Dublin, Ireland.
authors.forename: Peter
authors.initials: P
authors.lastname: Whitty
authors.forename: Mary
authors.initials: M
authors.lastname: Clarke
authors.forename: Orfhlaith
authors.initials: O
authors.lastname: McTigue
authors.forename: Stephen
authors.initials: S
authors.lastname: Browne
authors.forename: Moyaad
authors.initials: M
authors.lastname: Kamali
authors.forename: Conall
authors.initials: C
authors.lastname: Larkin
authors.forename: Eadbhard
authors.initials: E
authors.lastname: O'Callaghan
mesh_terms: D000328:Adult; D000341:Affective Disorders, Psychotic / Q000175:diagnosis / Q000453:epidemiology; D000437:Alcoholism / Q000175:diagnosis / Q000453:epidemiology; D015897:Comorbidity; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology; D003937:Diagnosis, Differential; D039721:Diagnostic and Statistical Manual of Mental Disorders; D004522:Educational Status; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011594:Psychometrics / Q000706:statistics & numerical data; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000453:epidemiology; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology