Traumatic Brain Injury and Depression in a Community-Based Sample: A Cohort Study Across the Adult Life Span.

OBJECTIVES: To determine whether self-reported traumatic brain injuries (TBIs) are associated with "cases" of clinically significant depression in the general community. To examine interactions between variables previously linked to depression after a TBI.

SETTING: Population-based community study (Canberra and Queanbeyan, Australia).

PARTICIPANTS AND DESIGN: Three age cohorts: young, middle-aged, and older adults (aged 20-24, 40-44, and 60-64 years at baseline) randomly selected from the electoral roll and followed across 3 waves (4 years apart). A total of 7397, 6621, and 6042 people provided their TBI history in waves 1 to 3.

MEASURES: Lifetime (TBIlifetime: sustained at any time since birth), recent (TBIrecent: in the preceding 4 years), and multiple (TBImultiple: more than 1) TBIs, current depression, and known risk factors for depression (age, sex, marital/employment status, prior history of depression, medical conditions, recent life events, alcohol consumption, social support, physical activity).

RESULTS: Generalized estimating equations demonstrated a significant association between sustaining a TBI and experiencing clinically significant depression (cases), even after controlling for multiple demographic and health/lifestyle factors.

CONCLUSION: There is an enduring association between depression and TBI, suggesting that, following a TBI, individuals should be monitored and supported to optimize their long-term psychological health.