Can traumatic brain injury cause psychiatric disorders?

Traumatic brain injury (TBI) may cause psychiatric illness. This article reviews the evidence on the basis of an established set of causation criteria. The evidence is convincing for a strong association between TBI and moon and anxiety disorders. Substance abuse and schizophrenia are not strongly associated with TBI and there is little search into the rates of personality disorders after TBI. Evidence for a biologic gradient is lacking, but such a gradient may not be relevant to TBI. Evidence for the correct temporal sequence is present. Preliminary evidence suggests a biologic rationale for TBI causing psychiatric illness. Further and methodologically improved research is supported and required.