Comparison of early and late depression after TBI; (the SHEFBIT study).

Objective: Evaluate the prevalence and risk factors for depression at 1 year after traumatic brain injury (TBI) and contrast against those at 10 weeks.

Methods: Prospective TBI admissions over 2 years to an emergency department were recruited to form a representative TBI population. Depression was recorded at 10 weeks and 1 year by HADS (Hospital Anxiety and Depression Scale) with score>8. Demographic and injury features were analyzed for association with depression.

Results: A total of 774 individuals were recruited of whom 690 attended  1-year follow-up; 38 had died. Only 6% of the cohort was lost to follow-up. The prevalence of depression at 10 weeks was 56.3% [95% CI 52.8-59.8] and at 1 year 41.2% [95% CI 37.6-44.9] A multivariable analysis identified the independent predictors of 1 year depression as an abnormal CT scan, past psychiatric history, alcohol intoxication, and female gender. TBI severity, age, etiology, and medical comorbidity were not significant. By contrast at 10weeks, increasing severity and CT findings were highly significant.

Conclusions: Depression at 1 year post-TBI remains high but injury features are less predictive than early after injury. It is likely that pre-injury personality and coping mechanisms are more important in determining long term outcome. The predictors identified may allow targeting of vulnerable sub-populations.