Psychiatric Disorders after TBI

April 20, 2016
Samantha J. Peterson

Does traumatic brain injury (TBI) inevitably lead to psychiatric disorders? Research presented at AAN 2016 aimed to quantify the risk of psychiatric illness after TBI.

The long-term consequences of traumatic brain injury (TBI) are profound. The burden of TBI is estimated to be $76 billion annually. Up to 60% of patients are unable to return to work after two years and 43% experience long-term disability.

While it is suspected that trauma plays a role in subsequent psychiatric disorders, the etiology is not well understood and little data exists supporting this hyothesis. Researchers from Weill Cornell Medical College, New York, NY and Columbia University, New York, NY aimed to quantify the risk of psychiatric illness after TBI.

A retrospective study of adult patients hospitalized for TBI at acute care hospitals in California, New York, and Florida between 2005 and 2012 was performed. TBI was defined according to the center for Disease Control’s definitions. Patients discharged home after the emergency department visit were considered to have mild TBI. Moderate TBI patients were those who did not require mechanical ventilation and severe patients required mechanical ventilation. An emergency department visit or hospitalization with a primary psychiatric diagnosis code, excluding those for dementia, served as the definition for psychiatric illness. Psychiatric diagnoses included depression, bipolar disorder, psychosis, personality disorders, substance abuse, anxiety disorders, post-traumatic stress disorder, and conduct disorders. To compare the incidence of psychiatric visits after TBI to patients’ baseline rate before TBI, researchers used Poisson regression with robust standard errors.

A total of 1,236,274 patients with TBI were identified. There were 1,007,494 patients with mild TBI, 202,063 with moderate TBI, and 26,717 with severe TBI. The mean follow-up period was 3.3 (±1.5) years before TBI and 2.8 (±1.5) years after TBI. The incidence rate of psychiatric visits was higher after TBI (incidence rate ratio [IRR], 1.36; 95% confidence interval [CI], 1.34-1.38). Severity of TBI did not significantly change findings: mild TBI (IRR, 1.39; 95% CI, 1.36-1.41), moderate TBI (IRR, 1.25; 95% CI, 1.20-1.30), and severe TBI (IRR, 1.35; 95% CI, 1.22-1.49).

Psychiatric visits after TBI, compared to the patients’ baseline rates, were significantly higher, independent of severity of injury. While not conclusive, findings were consistent with the researchers’ hypothesis that TBI results in adverse psychiatric disorders.

Reference: Merkler A, et al. Risk of Psychiatric Disorders after Traumatic Brain Injury. Poster presentation P3.341, Apr 18, 2016. AAN Annual Meeting, Vancouver, British Columbia.