%0 Journal Article %A Gabrielle F. Miller %A Hong Zhou %A Alexis B. Peterson %A Elizabeth Swedo %A Kristin Holland %A Marcie-jo Kresnow %T Association between traumatic brain injury and suicidality using a mediation approach and MarketScan %D 2022 %R 10.1136/ip-2022-044697 %J Injury Prevention %P ip-2022-044697 %X Introduction Negative outcomes, including suicidal ideation/attempts, are a major public health concern, particularly among individuals who sustain a traumatic brain injury (TBI). TBI is associated with high rates of postinjury substance use, psychiatric disorders, post-traumatic stress disorder and sleep disturbances. This study examines the mediation effects of substance use, psychiatric disorder and sleep disorder on the associations between TBI and suicidal ideation/attempts.Methods A matched case–control study using data from MarketScan databases for private health insurance and Medicaid from October 2015 to December 2018 estimated the association between TBI and suicidal ideation/attempts using a mediation approach. Individuals less than 65 years of age were included.Results In the Medicaid sample, psychiatric disorders mediated 22.4% of the total effect between TBI and suicidal ideation/attempt, while substance use disorders other than opioid use disorder mediated 7.47%. In the private health insurance sample, psychiatric disorders mediated 3.97% of the total effect, opioid use disorders mediated 2.08% of the total effect and sleep disorder mediated 1.25% of the total effect.Conclusions Mediators explained less than 30% of the relationship between TBI and suicidal ideation/attempt. Findings reinforce the importance of primary prevention of TBI and monitoring patients with a TBI for risk of suicide in the first 6–12 months following injury.Data may be obtained from a third party and are not publicly available. Data are available through IBM MarketScan Research. %U https://injuryprevention.bmj.com/content/injuryprev/early/2022/12/04/ip-2022-044697.full.pdf