Traumatic Brain Injury and Suicidal Thoughts and Behaviors among Post-9/11 Veterans: Investigating Longitudinal Change and Interactions with Mental Health.

Veterans die by suicide at almost twice the rate of non-veterans, and risks for suicide can be further increased after sustaining traumatic brain injury (TBI). This is notable, given that over 20 % of post-9/11 Veterans are estimated to have experienced TBI. Better understanding risk for suicidal thoughts and behaviors (STBs) would allow for improved screening processes and targeted treatment approaches. In this study, we use data from 823 veterans who served after September 11, 2001 and participated in the VISN 6 MIRECC's Post-Deployment Mental Health Study. In total, 511 (62.1 %) veterans reported at least one TBI during their lifetime and 241 (29.3 %) reporting at least one TBI during military deployment. Veterans had more STBs at baseline if they also reported more lifetime TBIs (β = 0.45, CI [0.18, 0.72], p < .001) or deployment TBI (β = 0.53, CI [0.16, 0.90], p = .005). When examining change over 12 years, veterans showed greater increases in STBs if they reported more lifetime TBIs (β = 0.34, CI [0.12, 0.55], p = .002) or deployment TBI (β = 0.62, CI [0.33, 0.91], p < .001). These associations remained when accounting for baseline mental health conditions (depressive symptoms, posttraumatic stress disorder symptoms, and lifetime trauma burden). All reported results accounted for age, gender, self-reported race/ethnic group, and education. Findings suggest that TBI is associated with increases in STBs and emergence of STBs over time. To better differentiate risk, screening measures and treatment for STBs should consider whether brain injury occurred in combat.