title: Adversity, cannabis use and psychotic experiences: evidence of cumulative and synergistic effects.
abstract: BACKGROUND
  There is robust evidence that childhood adversity is associated with an increased risk of psychosis. There is, however, little research on intervening factors that might increase or decrease risk following childhood adversity.
  
  
  OBJECTIVE
  To investigate main effects of, and synergy between, childhood abuse and life events and cannabis use on odds of psychotic experiences.
  
  
  METHODS
  Data on psychotic experiences and childhood abuse, life events and cannabis use were collected from 1680 individuals as part of the South East London Community Health Study (SELCoH), a population-based household survey.
  
  
  RESULTS
  There was strong evidence that childhood abuse and number of life events combined synergistically to increase odds of psychotic experiences beyond the effects of each individually. There was similar, but weaker, evidence for cannabis use (past year).
  
  
  CONCLUSIONS
  Our findings are consistent with the hypothesis that childhood abuse creates an enduring vulnerability to psychosis that is realised in the event of exposure to further stressors and risk factors.
authors.affiliation: Craig Morgan, PhD, Ulrich Reininghaus, PhD, NIHR Biomedical Research Centre and Section of Social Psychiatry, Health Service and Population Research Department, Institute of Psychiatry, King's College London, UK; Abraham Reichenberg, PhD, Department of Psychiatry, Mount Sinai School of Medicine, New York, USA; Souci Frissa, PhD, Matthew Hotopf, MBBS, PhD, Stephani L. Hatch, PhD, Psychological Medicine, Department, Institute of Psychiatry, King's College London, UK.
authors.forename: Craig
authors.initials: C
authors.lastname: Morgan
authors.forename: Ulrich
authors.initials: U
authors.lastname: Reininghaus
authors.forename: Abraham
authors.initials: A
authors.lastname: Reichenberg
authors.forename: Souci
authors.initials: S
authors.lastname: Frissa
authors.forename: Matthew
authors.initials: M
authors.lastname: Hotopf
authors.forename: Stephani L
authors.initials: SL
authors.lastname: Hatch
mesh_terms: D000293:Adolescent; D000328:Adult; D054523:Adult Survivors of Child Abuse / Q000523:psychology*; D005260:Female; D006801:Humans; D008016:Life Change Events; D008297:Male; D002189:Marijuana Abuse / Q000150:complications* / Q000523:psychology; D008385:Marijuana Smoking / Q000009:adverse effects* / Q000523:psychology; D008875:Middle Aged; D011618:Psychotic Disorders / Q000209:etiology* / Q000523:psychology; D011795:Surveys and Questionnaires; D055815:Young Adult