Suicide-related outcomes in veterans with post-traumatic headache: a retrospective cohort study.

Background: Post-traumatic headache (PTH) is a common sequela of traumatic brain injury (TBI). Although there is a known association between TBI and suicide risk in veterans, the association between PTH and suicide-related outcomes in veterans with TBI is relatively unknown. We aimed to evaluate the association between PTH and suicide-related outcomes in veterans compared to matched controls diagnosed with TBI but no history of headaches. Methods: This retrospective cohort study was conducted with Veterans Health Administration and Department of Defense electronic health record data from fiscal years 2008 through 2020. Veterans with PTH were matched to a control group who had TBI and no headache disorders. Relative risk was estimated using propensity score-weighted log-binomial models that evaluated differences in suicidal ideation, suicide attempts, and suicide death. Findings: Of the 95,224 veterans included in the total sample, 85,730 were male (90.0%) and 9,949 were female (10.0%). The average age of the sample was 45.9 years (SD = 16.6). 73,500 (77.2%) were White, Non-Hispanic, 17,256 (18.1%) were Black, Non-Hispanic, and 4,468 (4.7%) were classified as other or mixed race. Of the 47,612 veterans diagnosed with PTH, 4,618 (9.7%) reported suicidal ideation or suicide attempts compared to 3,162 (6.6%) in the control group. Veterans with PTH had increased risk of suicidal ideation (RR, 1.45; 95% CI, 1.39-1.51) and suicide attempts (RR, 1.66; 95% CI, 1.50-1.83) compared to matched controls. Using inverse probability weighting to adjust for confounding, these results remained significant. When adjusting for potential confounders, as well as prior suicidal ideation or suicide attempts, there was no significant difference in risk of suicide death in veterans with PTH (RR, 0.83; 95% CI, 0.67-1.02) compared to those with TBI without headache. Interpretation: Veterans with PTH have an increased risk of suicidal ideation and suicide attempts compared to veterans with TBI and without headache. There was no difference in suicide mortality between the two groups. Clinicians should be aware of heightened suicide risk among veterans with PTH and be especially diligent in terms of screening for suicide risk and related medical and mental health comorbidities that contribute to increased risk. Funding: This study was supported by the United States Department of Veterans Affairs special purpose medical service funding (SP80DPE.1-0160).