Is traumatic brain injury a risk factor for schizophrenia? A meta-analysis of case-controlled population-based studies

Schizophr Bull. 2011 Nov;37(6):1104-10. doi: 10.1093/schbul/sbr091. Epub 2011 Aug 2.

Abstract

Traumatic brain injury (TBI) is known to lead to a range of adverse psychiatric sequelae but the question of whether TBI is a risk factor for psychosis and, in particular, schizophrenia remains unclear. Studies examining this issue have yielded conflicting results. We carried out a systematic review of the literature on TBI and psychosis in order to identify all population-based controlled studies which provide estimates of risk for schizophrenia following TBI. Odds ratios (ORs) were combined using random effects meta-analysis. Our literature search yielded 172 studies which were considered to be potentially relevant. From these, we identified 9 studies that could provide estimates of risk in the form of ORs. The pooled analysis revealed a significant association between TBI and schizophrenia (OR = 1.65; 95% CI = 1.17-2.32), with significant heterogeneity between the studies. Estimates from the family studies (OR = 2.8: 95% CI =1.76-4.47) were higher than those from the cohort/nested case-control studies (OR = 1.42: 95% CI = 1.02-1.97) by a factor of almost 2. There did not appear to be a dose-response relationship between severity of head injury and subsequent risk of schizophrenia. This meta-analysis supports an increased risk of schizophrenia following TBI, with a larger effect in those with a genetic predisposition to psychosis. Further epidemiological and neuroscientific studies to elucidate the mechanisms underlying this association are warranted.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Brain Injuries / complications*
  • Brain Injuries / psychology*
  • Humans
  • Psychotic Disorders / epidemiology
  • Psychotic Disorders / etiology
  • Psychotic Disorders / psychology
  • Research Design
  • Risk Factors
  • Schizophrenia / epidemiology
  • Schizophrenia / etiology*