title: Exposure to stressful life events during pregnancy predicts psychotic experiences via behaviour problems in childhood.
abstract: BACKGROUND
  Exposure to stressful life events during pregnancy has been associated with later schizophrenia in offspring. We explore how prenatal stress and neurodevelopmental abnormalities in childhood associate to increase the risk of later psychotic experiences.
  
  
  METHODS
  Participants from the Mater University Study of Pregnancy (MUSP), an Australian based, pre-birth cohort study were examined for lifetime DSM-IV positive psychotic experiences at 21 years by a semi-structured interview (n = 2227). Structural equation modelling suggested psychotic experiences were best represented with a bifactor model including a general psychosis factor and two group factors. We tested for an association between prenatal stressful life events with the psychotic experiences, and examined for potential moderation and mediation by behaviour problems and cognitive ability in childhood.
  
  
  RESULTS
  Prenatal stressful life events predicted psychotic experiences indirectly via behaviour problems at child age five years, and this relationship was not confounded by maternal stressful life events at child age five. We found no statistical evidence for an interaction between prenatal stressful life events and behaviour problems or cognitive ability.
  
  
  CONCLUSIONS
  The measurable effect of prenatal stressful life events on later psychotic experiences in offspring manifested as behaviour problems by age 5. By identifying early abnormal behavioural development as an intermediary, this finding further confirms the role of prenatal stress to later psychotic disorders.
authors.affiliation: School of Population Health, University of Queensland, Brisbane, Australia. Electronic address: kim.betts@uqconnect.edu.au.
authors.forename: Kim S
authors.initials: KS
authors.lastname: Betts
authors.affiliation: School of Population Health, University of Queensland, Brisbane, Australia. Electronic address: g.williams@sph.uq.edu.au.
authors.forename: Gail M
authors.initials: GM
authors.lastname: Williams
authors.affiliation: School of Social Science and Population Health, University of Queensland, Brisbane, Australia. Electronic address: j.najman@uq.edu.au.
authors.forename: Jakob M
authors.initials: JM
authors.lastname: Najman
authors.affiliation: The University of Queensland Centre for Clinical Research and Metro North Mental Health, Royal Brisbane and Women's Hospital, Brisbane, Australia. Electronic address: james.scott@health.qld.gov.au.
authors.forename: James
authors.initials: J
authors.lastname: Scott
authors.affiliation: School of Public Health and Centre for Youth Substance Abuse Research, University of Queensland, Brisbane, Australia. Electronic address: r.alati@sph.uq.edu.au.
authors.forename: Rosa
authors.initials: R
authors.lastname: Alati
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008016:Life Change Events; D008297:Male; D008423:Maternal Age; D008962:Models, Theoretical; D011237:Predictive Value of Tests; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000503:physiopathology*; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000209:etiology* / Q000523:psychology*; D013315:Stress, Psychological / Q000150:complications*; D055815:Young Adult
keywords: Behavioural problems; Cognitive ability; Mediation; Neurodevelopment; Prenatal stressful life events; Psychotic experiences