Patterns of Depression Treatment in Medicare Beneficiaries with Depression after Traumatic Brain Injury

There are no clinical guidelines addressing the management of depression after traumatic brain injury (TBI). The objectives of this study were to (1) describe depression treatment patterns among Medicare beneficiaries with a diagnosis of depression post-TBI; (2) compare them with depression treatment patterns among beneficiaries with a diagnosis of depression pre-TBI; and (3) quantify the difference in prevalence of use. We conducted a retrospective analysis of Medicare beneficiaries hospitalized with TBI during 2006-2010. We created two cohorts: beneficiaries with a new diagnosis of depression pre-TBI (n=4841) and beneficiaries with a new diagnosis of depression post-TBI (n=4668). We searched for antidepressant medications in Medicare Part D drug event files and created variables indicating antidepressant use in each 30-day period after diagnosis of depression. We used provider specialty and current procedural terminology to identify psychotherapy in any location. We used generalized estimating equations to quantify the effect of TBI on receipt of depression treatment during the year after diagnosis of depression. Average monthly prevalence of antidepressant use was 42% among beneficiaries with a diagnosis of depression pre-TBI and 36% among those with a diagnosis post-TBI (p<0.001). Beneficiaries with a diagnosis of depression post-TBI were less likely to receive antidepressants compared with a depression diagnosis pre-TBI (adjusted odds ratio [OR] 0.87; 95% confidence interval [CI] 0.82, 0.92). There was no difference in receipt of psychotherapy between the two groups (OR 1.08; 95% CI 0.93, 1.26). Depression after TBI is undertreated among older adults. Knowledge about reasons for this disparity and its long-term effects on post-TBI outcomes is limited and should be examined in future work.