title: Specificity of childhood psychotic symptoms for predicting schizophrenia by 38 years of age: a birth cohort study.
abstract: BACKGROUND
  Childhood psychotic symptoms have been used as a subclinical phenotype of schizophrenia in etiological research and as a target for preventative interventions. However, recent studies have cast doubt on the specificity of these symptoms for schizophrenia, suggesting alternative outcomes such as anxiety and depression. Using a prospective longitudinal birth cohort we investigated whether childhood psychotic symptoms predicted a diagnosis of schizophrenia or other psychiatric disorders by 38 years of age.
  
  
  METHODS
  Participants were drawn from a birth cohort of 1037 children from Dunedin, New Zealand, who were followed prospectively to 38 years of age (96% retention rate). Structured clinical interviews were administered at age 11 to assess psychotic symptoms and study members underwent psychiatric assessments at ages 18, 21, 26, 32 and 38 to obtain past-year DSM-III-R/IV diagnoses and self-reports of attempted suicides since adolescence.
  
  
  RESULTS
  Psychotic symptoms at age 11 predicted elevated rates of research diagnoses of schizophrenia and posttraumatic stress disorder (PTSD) and also suicide attempts by age 38, even when controlling for gender, social class and childhood psychopathology. No significant associations were found for persistent anxiety, persistent depression, mania or persistent substance dependence. Very few of the children presenting with age-11 psychotic symptoms were free from disorder by age 38.
  
  
  CONCLUSIONS
  Childhood psychotic symptoms were not specific to a diagnosis of schizophrenia in adulthood and thus future studies of early symptoms should be cautious in extrapolating findings only to this clinical disorder. However, these symptoms may be useful as a marker of adult mental health problems more broadly.
authors.affiliation: MRC Social Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, UK. helen.2.fisher@kcl.ac.uk
authors.forename: H L
authors.initials: HL
authors.lastname: Fisher
authors.forename: A
authors.initials: A
authors.lastname: Caspi
authors.forename: R
authors.initials: R
authors.lastname: Poulton
authors.forename: M H
authors.initials: MH
authors.lastname: Meier
authors.forename: R
authors.initials: R
authors.lastname: Houts
authors.forename: H
authors.initials: H
authors.lastname: Harrington
authors.forename: L
authors.initials: L
authors.lastname: Arseneault
authors.forename: T E
authors.initials: TE
authors.lastname: Moffitt
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D015897:Comorbidity; D006801:Humans; D009520:New Zealand / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011618:Psychotic Disorders / Q000453:epidemiology*; D012559:Schizophrenia / Q000453:epidemiology*; D013313:Stress Disorders, Post-Traumatic / Q000453:epidemiology; D013406:Suicide, Attempted / Q000706:statistics & numerical data; D055815:Young Adult