title: Interplay between childhood physical abuse and familial risk in the onset of psychotic disorders.
abstract: BACKGROUND
  Childhood abuse is considered one of the main environmental risk factors for the development of psychotic symptoms and disorders. However, this association could be due to genetic factors influencing exposure to such risky environments or increasing sensitivity to the detrimental impact of abuse. Therefore, using a large epidemiological case-control sample, we explored the interplay between a specific form of childhood abuse and family psychiatric history (a proxy for genetic risk) in the onset of psychosis.
  
  
  METHODS
  Data were available on 172 first presentation psychosis cases and 246 geographically matched controls from the Aetiology and Ethnicity of Schizophrenia and Other Psychoses study. Information on childhood abuse was obtained retrospectively using the Childhood Experience of Care and Abuse Questionnaire and occurrence of psychotic and affective disorders in first degree relatives with the Family Interview for Genetic Studies.
  
  
  RESULTS
  Parental psychosis was more common among psychosis cases than unaffected controls (adjusted OR = 5.96, 95% CI: 2.09-17.01, P = .001). Parental psychosis was also associated with physical abuse from mothers in both cases (OR = 3.64, 95% CI: 1.06-12.51, P = .040) and controls (OR = 10.93, 95% CI: 1.03-115.90, P = .047), indicative of a gene-environment correlation. Nevertheless, adjusting for parental psychosis did not measurably impact on the abuse-psychosis association (adjusted OR = 3.31, 95% CI: 1.22-8.95, P = .018). No interactions were found between familial liability and maternal physical abuse in determining psychosis caseness.
  
  
  CONCLUSIONS
  This study found no evidence that familial risk accounts for associations between childhood physical abuse and psychotic disorder nor that it substantially increases the odds of psychosis among individuals reporting abuse.
authors.affiliation: MRC Social Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK; helen.2.fisher@kcl.ac.uk.
authors.forename: Helen L
authors.initials: HL
authors.lastname: Fisher
authors.affiliation: MRC Social Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, King's College London, London, UK;
authors.forename: Peter
authors.initials: P
authors.lastname: McGuffin
authors.affiliation: Psychosis Studies, Institute of Psychiatry, King's College London, London, UK;
authors.forename: Jane
authors.initials: J
authors.lastname: Boydell
authors.affiliation: Department of Psychiatry, Trinity College Dublin, Dublin, Ireland;
authors.forename: Paul
authors.initials: P
authors.lastname: Fearon
authors.affiliation: Health Services & Population Research, Institute of Psychiatry, King's College London, London, UK;
authors.forename: Thomas K
authors.initials: TK
authors.lastname: Craig
authors.affiliation: Psychosis Studies, Institute of Psychiatry, King's College London, London, UK; National Institute of Health Research Biomedical Research Centre for Mental Health, London, UK;
authors.forename: Paola
authors.initials: P
authors.lastname: Dazzan
authors.affiliation: Department of Psychology, University of Westminster, London, UK;
authors.forename: Kevin
authors.initials: K
authors.lastname: Morgan
authors.affiliation: Division of Psychiatry, University of Nottingham, Nottingham, UK;
authors.forename: Gillian A
authors.initials: GA
authors.lastname: Doody
authors.affiliation: Department of Psychiatry, University of Cambridge, Cambridge, UK;
authors.forename: Peter B
authors.initials: PB
authors.lastname: Jones
authors.affiliation: Mental Health Sciences, University College London, London, UK.
authors.forename: Julian
authors.initials: J
authors.lastname: Leff
authors.affiliation: Psychosis Studies, Institute of Psychiatry, King's College London, London, UK; National Institute of Health Research Biomedical Research Centre for Mental Health, London, UK;
authors.forename: Robin M
authors.initials: RM
authors.lastname: Murray
authors.affiliation: Health Services & Population Research, Institute of Psychiatry, King's College London, London, UK; National Institute of Health Research Biomedical Research Centre for Mental Health, London, UK;
authors.forename: Craig
authors.initials: C
authors.lastname: Morgan
mesh_terms: D000293:Adolescent; D000328:Adult; D002649:Child Abuse / Q000523:psychology*; D005260:Female; D059647:Gene-Environment Interaction; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009034:Mother-Child Relations / Q000523:psychology*; D010290:Parents / Q000523:psychology*; D011618:Psychotic Disorders / Q000209:etiology* / Q000235:genetics; D055815:Young Adult
keywords: family history; gene-environment correlation; gene-environment interaction; liability; schizophrenia; trauma