Psychiatric comorbidity following traumatic brain injury

Primary objective: Survivors of traumatic brain injury (TBI) are at increased risk for development of severe, long-term psychiatric disorders. However, the aetiology of these disorders remains unclear. This article systematically reviews the most current prevalence rates and evidence for causality, in terms of established criteria. Main outcome and results: Psychiatric syndromes are consistently present at an elevated rate following TBI. Survivors of TBI are particularly susceptible to major depression, generalized anxiety disorder and post-traumatic stress disorder. Evidence for a biological gradient is generally lacking, although this criterion may not be appropriate in the case of TBI. The temporal pattern of onset is variable and reliable critical periods for the post-injury development of a psychiatric disorder remain to be identified; however, individuals appear to remain at risk for years following injury. Conclusions: Non-organic factors, including pre-morbid personality traits and post-injury psychological reactions to disability and trauma, are implicated in the generation and maintenance of post-TBI psychiatric disorder. There remains insufficient evidence to conclude what role the neuropathological consequences of TBI play in the development of post-TBI psychiatric disorder.