title: Psychotic experiences and risk of self-injurious behaviour in the general population: a systematic review and meta-analysis.
abstract: BACKGROUND
  Recent studies suggest that psychotic experiences (PE) in the general population are associated with an increased risk of self-injurious behaviour. Both the magnitude of this association and the level of adjustment for confounders vary among studies. A meta-analysis was performed to integrate the available evidence. The influence of possible confounders, including variably defined depression, was assessed.
  
  
  METHODS
  A systematic review and meta-analysis was conducted including general population studies reporting on the risk of self-injurious behaviour in individuals with PE. Studies were identified by a systematic search strategy in Pubmed, PsycINFO and Embase. Reported effect sizes were extracted and meta-analytically pooled.
  
  
  RESULTS
  The risk of self-injurious behaviour was 3.20 times higher in individuals with PE compared with those without. Subanalyses showed that PE were associated with self-harm, suicidal ideation as well as suicidal attempts. All studies had scope for considerable residual confounding; effect sizes adjusted for depression were significantly smaller than effect sizes unadjusted for depression. In the longitudinal studies, adjustment for psychopathology resulted in a 74% reduction in excess risk.
  
  
  CONCLUSIONS
  PE are associated with self-injurious behaviour, suggesting they have potential as passive markers of suicidality. However, the association is confounded and several methodological issues remain, particularly how to separate PE from the full range of connected psychopathology in determining any specific association with self-injurious behaviour. Given evidence that PE represent an indicator of severity of non-psychotic psychopathology, the association between PE and self-injurious behaviour probably reflects a greater likelihood of self-injurious behaviour in more severe states of mental distress.
authors.affiliation: Department of Psychiatry and Psychology,South Limburg Mental Health Research and Teaching Network,Maastricht University Medical Centre,Maastricht,The Netherlands.
authors.forename: S
authors.initials: S
authors.lastname: Honings
authors.affiliation: Department of Psychiatry and Psychology,South Limburg Mental Health Research and Teaching Network,Maastricht University Medical Centre,Maastricht,The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Drukker
authors.affiliation: Faculty of Psychology and Neuroscience,Maastricht University,Maastricht,The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Groen
authors.affiliation: Department of Psychiatry and Psychology,South Limburg Mental Health Research and Teaching Network,Maastricht University Medical Centre,Maastricht,The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: van Os
mesh_terms: D003702:Delusions / Q000453:epidemiology*; D006212:Hallucinations / Q000453:epidemiology*; D006801:Humans; D011618:Psychotic Disorders / Q000453:epidemiology*; D012307:Risk Factors; D016728:Self-Injurious Behavior / Q000453:epidemiology*; D059020:Suicidal Ideation; D013406:Suicide, Attempted / Q000706:statistics & numerical data*
keywords: Meta-analyses; non-suicidal self-injury; psychotic experiences; self-injurious behaviour; suicide