Traumatic Brain Injury and Psychosis: What Is the Connection?

Psychotic syndromes occur more frequently in individuals who have had a traumatic brain injury (TBI) than in the general population. Psychotic syndromes following a TBI can present in the period of post-traumatic anmesia, in association with post-traumatic epilepsy, in association with TBI-related mood disorders, and as a chronic, schizophrenia-like syndrome. Individuals with schizophrenia (a chronic psychotic disorder) have a higher frequency of prior TBI than individuals with other psychiatric disorders. These observations suggest an intriguing link between psychosis and TBI. The study of the neuroanatomical and neuropathological substrate of schizophrenia, and of the core symptoms of the disorder ("negative" symptoms, hallucinations, delusions), suggests that abnormalities in the structure and function of certain brain regions play a role in the genesis and maintenance of these core symptoms. The key brain regions include the dorsolateral prefrontal cortex, temporal lobe structures, basal ganglia, thalamus, and cingulate gyrus. These brain regions are commonly injured in many patients with TBI, suggesting a possible mechanism underlying the observed link between TBI and psychosis. This article reviews the literature on TBI and psychosis, and suggests an approach to the evaluation and treatment of individuals with TBI and psychosis.