title: Lifetime prevalence of psychotic and bipolar I disorders in a general population.
abstract: BACKGROUND
  Recent general population surveys of psychotic disorders have found low lifetime prevalences. However, this may be owing to methodological problems. Few studies have reported the prevalences of all specific psychotic disorders.
  
  
  OBJECTIVE
  To provide reliable estimates of the lifetime prevalences of specific psychotic disorders.
  
  
  METHODS
  General population survey.
  
  
  METHODS
  A nationally representative sample of 8028 persons 30 years or older was screened for psychotic and bipolar I disorders using the Composite International Diagnostic Interview, self-reported diagnoses, medical examination, and national registers. Those selected by the screens were then re-interviewed with the Structured Clinical Interview for DSM-IV. Best-estimate DSM-IV diagnoses were formed by combining the interview and case note data. Register diagnoses were used to estimate the effect of the nonresponders.
  
  
  METHODS
  Diagnosis of any psychotic or bipolar I disorder according to the DSM-IV criteria.
  
  
  RESULTS
  The lifetime prevalence of all psychotic disorders was 3.06% and rose to 3.48% when register diagnoses of the nonresponder group were included. Lifetime prevalences were as follows: 0.87% for schizophrenia, 0.32% for schizoaffective disorder, 0.07% for schizophreniform disorder, 0.18% for delusional disorder, 0.24% for bipolar I disorder, 0.35% for major depressive disorder with psychotic features, 0.42% for substance-induced psychotic disorders, and 0.21% for psychotic disorders due to a general medical condition. The National Hospital Discharge Register was the most reliable of the screens (kappa = 0.80). Case notes supplementing the interviews were essential for specific diagnoses of psychotic disorders.
  
  
  CONCLUSIONS
  Multiple sources of information are essential for accurate estimation of lifetime prevalences of psychotic disorders. The use of comprehensive methods reveals that their lifetime prevalence exceeds 3%.
authors.affiliation: Department of Mental Health and Alcohol Research, National Public Health Institute, University of Helsinki, Mannerheimintie 166, 0300 Helsinki, Finland. jonna.perala@ktl.fi
authors.forename: Jonna
authors.initials: J
authors.lastname: Perälä
authors.forename: Jaana
authors.initials: J
authors.lastname: Suvisaari
authors.forename: Samuli I
authors.initials: SI
authors.lastname: Saarni
authors.forename: Kimmo
authors.initials: K
authors.lastname: Kuoppasalmi
authors.forename: Erkki
authors.initials: E
authors.lastname: Isometsä
authors.forename: Sami
authors.initials: S
authors.lastname: Pirkola
authors.forename: Timo
authors.initials: T
authors.lastname: Partonen
authors.forename: Annamari
authors.initials: A
authors.lastname: Tuulio-Henriksson
authors.forename: Jukka
authors.initials: J
authors.lastname: Hintikka
authors.forename: Tuula
authors.initials: T
authors.lastname: Kieseppä
authors.forename: Tommi
authors.initials: T
authors.lastname: Härkänen
authors.forename: Seppo
authors.initials: S
authors.lastname: Koskinen
authors.forename: Jouko
authors.initials: J
authors.lastname: Lönnqvist
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology*; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005387:Finland / Q000453:epidemiology; D006304:Health Status; D006306:Health Surveys; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods; D008875:Middle Aged; D015995:Prevalence; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology*; D012042:Registries; D012107:Research Design; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires