Changes in depression symptoms over 10 years after TBI; a long-term prospective study.

Objective: Evaluate the prevalence and risk factors associated with depression symptoms at 10 years after traumatic brain injury (TBI) and compare with results at 10 weeks and 1 year.

Methods: A large cohort of prospective admissions with TBI were followed up for 10 years. Depression using HADS (Hospital Anxiety and Depression Scale) score > 8 was measured. Several injury and demographic features were examined for association with depression.

Results: Over 4 years, 1130 individuals were recruited of whom 916 attended at 1 year; after 10 years, 552 attended and 210 had died. 154 (17%) of the cohort was lost to follow-up. The prevalence of depression at 10 weeks was 56.3% [95%CI 52.2-60.5], at 1 year was 42.4% [95%CI 38.3-46.5] and 10 years 38.4% [95%CI 34.3-42.5]. There was considerable change in individual scores over time in both directions. A multivariable analysis identified the independent predictors of 10-year depression score as lower GCS, social deprivation, female gender, past psychiatric history, alcohol intoxication and unemployment. Age, ethnicity, social support, TBI etiology, CT abnormality and medical comorbidity were insignificant.

Conclusions: While the overall level of symptoms at 10-year post-TBI remains high, there is considerable change in individual depression status over time. The predictors identified may allow the targeting of vulnerable sub-populations.