title: Childhood trauma and psychosis: a case-control and case-sibling comparison across different levels of genetic liability, psychopathology, and type of trauma.
abstract: OBJECTIVE
  The associations of two types of childhood trauma (abuse and neglect) with psychosis symptom domains were investigated in subjects with psychotic illness, high psychosis vulnerability, and average psychosis vulnerability.
  
  
  METHODS
  Childhood trauma was assessed with the Childhood Trauma Questionnaire. Symptoms were assessed with the Positive and Negative Syndrome Scale in the patients (N=272) and with the Structured Interview for Schizotypy-Revised in the patients' siblings (N=258), and healthy comparison subjects (N=227).
  
  
  RESULTS
  Childhood trauma was associated with psychotic disorder in a dose-response fashion in the comparison of patients and healthy subjects (adjusted odds ratio=4.53, 95% CI=2.79-7.35). The comparison of siblings and healthy subjects suggested that siblings shared a degree of trauma with the patients (adjusted odds ratio=1.61, 95% CI=0.95-2.61), but the patient-sibling comparison indicated much greater exposure in patients than in siblings (adjusted odds ratio=2.60, 95% CI=1.78-3.78). Childhood abuse but not neglect was associated with positive but not negative symptoms in a dose-response fashion in all three groups. There was no evidence for moderation by sex.
  
  
  CONCLUSIONS
  Discordance in psychotic illness across related individuals can be traced to differential exposure to trauma. The association between trauma and psychosis is apparent across different levels of illness and vulnerability to psychotic disorder, suggesting true association rather than reporting bias, reverse causality, or passive gene-environment correlation. Positive psychotic symptoms in vulnerable individuals may arise as a consequence of the level and frequency of exposure to abuse rather than neglect, suggesting symptom-specific and exposure-specific underlying mechanisms.
authors.affiliation: Department of Psychiatry and Neuropsychology, European Graduate School of Neuroscience, South Limburg Mental Health Research and Teaching Network, Maastricht, the Netherlands.
authors.forename: Manuela
authors.initials: M
authors.lastname: Heins
authors.forename: Claudia
authors.initials: C
authors.lastname: Simons
authors.forename: Tineke
authors.initials: T
authors.lastname: Lataster
authors.forename: Stefanie
authors.initials: S
authors.lastname: Pfeifer
authors.forename: Dagmar
authors.initials: D
authors.lastname: Versmissen
authors.forename: Marielle
authors.initials: M
authors.lastname: Lardinois
authors.forename: Machteld
authors.initials: M
authors.lastname: Marcelis
authors.forename: Philippe
authors.initials: P
authors.lastname: Delespaul
authors.forename: Lydia
authors.initials: L
authors.lastname: Krabbendam
authors.forename: Jim
authors.initials: J
authors.lastname: van Os
authors.forename: Inez
authors.initials: I
authors.lastname: Myin-Germeys
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002649:Child Abuse / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000175:diagnosis / Q000209:etiology*; D035781:Siblings; D011795:Surveys and Questionnaires