Comorbidity of Headache and Depression after Mild Traumatic Brain Injury

Objective To examine headache and depression over time in individuals who sustained mild traumatic brain injury (mTBI). Prevalence of headache and depression early after mTBI and at 1 year postinjury as well as the relationship between the two are evaluated. Background Headache is the most common physical symptom and depression is among the most common psychiatric diagnosis after traumatic brain injury regardless of severity. Headache and depression have been found to be two independent factors related to poor outcome after mTBI, yet there appears to be a paucity of research exploring the comorbidity of these two conditions after injury. Method/Design Longitudinal survey design over 1 year of 212 participants with mTBI who were admitted to a Level 1 trauma center for observation or other system injuries. Depression was based on a score ≥10 on the Patient Health Questionnaire-9. Headache was based on participant report of new or worse-than-preinjury headache since hospitalization (baseline) or within the previous 3 months at 1 year postinjury. Results The prevalence of headache and depression at baseline was 64% (135/212) and 15% (31/212), respectively. The prevalence of headache and depression at 1 year was 68% (127/187) and 27% (50/187), respectively. The co-occurrence of headache and depression increased from 11% (23/212) at baseline to 25% (46/187) at 1 year. At 1 year, the risk ratio of individuals who had headache to be depressed was 5.43 (95% CI 2.05-14.40) compared to those without headache (P <.001). The corresponding risk ratio at baseline was 1.64 (95% CI.77-3.49; P =.23). Conclusions While prevalence of headache is consistently high over the first year after injury, rate of depression increased over the first year for those who were followed. Given the high rate of comorbidity, those with headache may develop depression over time. Evaluation for possible depression in those with headache after mTBI should be conducted to address both conditions over the year following injury.