- Substantial psychological and neurobehavioural evidence is available to support the hypothesis that traumatic brain injury (TBI) is a risk factor for subsequent psychiatric disorders. However, studies utilizing established psychiatric diagnostic schemes to study these outcomes after TBI are scarce, and no studies have included an assessment of personality disorders in addition to the major psychiatric disorders. This study utilizes structured psychiatric interviews to measure the prevalence of DSM-III(R) disorders in a sample of 18 subjects derived from a TBI rehabilitation programme. Results revealed high rates for major depression, bipolar affective disorder, generalized anxiety disorder, borderline and avoidant personality disorders. Co-morbidity was also high. A preliminary study of postulated predictive factors revealed possible roles for sex and for initial severity of injury. The study supports the association between TBI and psychiatric disorder, and suggests the need for monitoring, for prevention, and for treatment of psychiatric disorders after TBI.