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Abstract
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Suicide in the military represents a significant and multifaceted problem, with complex and interdependent factors contributing to its occurrence. Disentangling the intricate temporal associations between suicide and its numerous risk factors poses a significant challenge. Of the purported risk factors, traumatic brain injury (TBI) has received special focus, given its unfortunate status as the signature injury in active duty service members who served in Operation Enduring Freedom and Operation Iraqi Freedom. The complex interplay between TBI, its potential effects on mental health, and risk of suicide remains a vexing focus of ongoing investigations and academic inquiry.
In this study, Brenner and colleagues1 present a retrospective cohort analysis of active duty service members in the Department of Defense Substance Use and Psychological Injury Combat Study. This large study includes more than 860 000 active duty service members returning from deployment in Afghanistan or Iraq and is bolstered by uniform access to participant records. Of note, 12.6% of the cohort had documentation of at least 1 TBI, but this likely represents an underestimate, given diagnostic difficulty associated with this injury and limits of electronic medical record review.1 Brenner et al1 compared the onset of new behavioral health conditions over time between a matched sample of active duty service members with and without documented, military-identified TBI. Although the cohort was mostly younger men, the striking findings include marked increases in mental health diagnoses, most notably mood (increased 67.7% in active duty service members with TBI vs 37.5% in those without) and substance use disorders (increased 100% in active duty service members with TBI vs 14.5% in those without). Brenner et al1 found that time to suicide was markedly faster among active duty service members with history of TBI compared with those without a history of TBI (21.3% faster; estimate, 0.787; 95% CI, 0.715-0.866), especially among individuals with new-onset substance use disorder (62.8% faster; estimate, 0.372; 95% CI, 0.322-0.433). This study underscores the burden of suicide and multidimensionality of suicide risk among military personnel and veterans.
The findings of this study are bolstered by its large numbers and uniform access to participant records. The data presented build on prior work suggesting that TBI may be facilitatory or causative of chronic disease.
FINDINGS from the National Institute on Disability, Independent Living, and Rehabilitation Research TBI Model System (NIDILRR TBIMS) reported a 9-year shorter life span2 and elevated behavioral health issues after moderate to severe TBI.3 Indeed, in another TBIMS study, Fisher and colleagues4 noted that individuals with TBI are at greater risk for depression and suicidal behavior many years after TBI.4 In a different civilian cohort of more than 9000 persons with TBI and controls, Izzy and colleagues5 demonstrated an enhanced odds ratio of psychiatric and general health disorders, including depression, anxiety, psychosis, and suicidal ideation, following TBI.5 Of interest, the study by Izzy et al5 demonstrated striking time-to-event links to psychiatric comorbidities, with the mild TBI cohort developing depression, anxiety, and alcohol use disorder significantly sooner than those without history of TBI. Together with the work of Brenner and colleagues,1 these studies suggest that an at-risk maladaptive phenotype exists and requires early identification. In addition, a study by Wilder and colleagues6 used a patient claims data set of more than 11 000 participants and noted that 48% were later diagnosed with a mental illness within 3 years following their concussion.6 Although neither Brenner and colleagues1 nor Wilder and colleagues6 corrected for visit frequency bias, Izzy and colleagues5 did do so and suggested that the behavioral health risk associated with TBI was not related to encounter bias. Using the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) data set, Stein and colleagues7 noted high rates of posttraumatic stress disorder (PTSD) and depression at 6-month follow-ups among individuals who presented to the emergency department with mild TBI.7 Critically, using the Injury and Traumatic Stress network, Fisher and colleagues8 noted that PTSD seems to be driving risk for suicidal behavior among individuals with mild TBI. Thus, these interaction terms warrant further examination. Using the same TRACK-TBI study, Nelson and colleagues9 noted marked functional limitations among more than 50% of individuals with mild TBI compared with orthopedic trauma controls at 1 year after injury, suggesting that maladaptation is common after mild TBI...
Language: en |