Psychiatric disorders following traumatic brain injury: their nature and frequency.

Objectives: To retrospectively establish the nature and frequency of Axis I psychiatric disorders pre- and post-TBI.
Participants: One hundred participants who were 0.5 to 5.5 years post mild to severe TBI and 87 informants, each evaluated at a single time point.
Main Measure: The Structured Clinical Interview for DSM-IV Disorders (SCID-I).
Results: Preinjury, 52% received a psychiatric diagnosis, most commonly substance use disorder (41%), followed by major depressive disorder (17%) and anxiety (13%). Postinjury, 65% received a diagnosis, of which major depression became the most common (45%), followed by anxiety (38%) and substance use disorder (21%). Frequency of depression, generalized anxiety disorder, posttraumatic stress disorder, panic disorder, and phobias rose from preinjury to postinjury. More than two-thirds of postinjury depression and anxiety cases were novel and showed poor resolution rates. Few novel cases of substance use disorder were noted. Psychotic disorders, somatoform disorders, and eating disorders occurred at frequencies similar to those in the general population.
Conclusions: A high frequency of postinjury psychiatric disorders was evident up to 5.5 years postinjury, with many novel cases of depression and anxiety. Individuals with TBI should be screened for psychiatric disorders at various time points post-injury without reliance on history of psychiatric problems to predict who is at risk, so that appropriate intervention can be offered.