Risk of Alcohol Use Disorder or Other Drug Use Disorder Among US Service Members Following Traumatic Brain Injury, 2008-2011

Objectives: Evaluate the risk of developing an alcohol use disorder (AUD) or other drug use disorder (ODUD) in U. S. service members (SMs) after incident traumatic brain injury (TBI) in both the deployed and the nondeployed setting. Participants and methods: Retrospective cohort study of U.S. SMs who served on active duty from January 1, 2008 to December 31, 2010. The exposed cohort consisted of SMs who received an incident diagnosis of TBI during the exposure period. The unexposed cohort was populated with a 10% random sample of SMs with any other medical diagnosis over the exposure period. Results: After adjusting for various demographic factors, TBI severity, historic diagnosis of post-traumatic stress disorder (PTSD), comorbid PTSD, and comorbid mental health outcomes, the TBI cohort (n = 53,817) demonstrated elevated incident rate ratio of developing AUD (adjusted incidence rate ratios (IRR) 1.5, 95% confidence interval (CI) 1.4, 1.6, p < 0.0001) as compared to an unexposed cohort (n = 151,776). The TBI cohort did not demonstrate elevated risk of ODUD as compared to the unexposed cohort (adjusted IRR 1.0, 95% CI 1.0, 1.2, p = 0.178). Conclusions: U.S. SMs diagnosed with incident TBI demonstrated increased risk of developing an AUD within 1 year of incident TBI as compared to SMs without diagnosed TBI.