Objective: This study examines the effect of preinjury depressive symptoms on outcomes 3 mos after complicated and uncomplicated cases of mild traumatic brain injury.
Design: Preinjury depressive symptoms, experienced in the 30 days before injury, as measured by retrospective self-report, were assessed within the first 2 wks after injury. The outcome measures assessed at 3 mos after injury included affective/behavioral, cognitive, and physical problems and health-related quality-of-life.
Results: There were 177 patients who completed both the baseline and 3-mo follow-up interviews. The sample was categorized by severity of depressive symptoms in the month before injury as normal, mild, or moderate-severe. Compared with those reporting no preinjury depressive symptoms, persons reporting moderate-severe depressive symptoms had significantly worse outcomes on the Affective and Behavioral and the Cognitive subscales of the Head Injury-Family Interview Problem Checklist and on the 36-item Short-Form Health Survey Mental Component Summary score. The group reporting mild preinjury depressive symptoms scored worse on a measure of cognitive symptoms compared with those with no preinjury depressive symptoms. There was no interaction between preinjury depressive symptoms and severity of the mild traumatic brain injury (complicated or uncomplicated) for any of the outcomes.
Conclusion: Moderate to severe depressive symptoms in the month before injury seems to be a possible risk factor for poor affective/behavioral, cognitive, and mental health-related quality-of-life outcomes at 3 mos after mild traumatic brain injury. Clinicians and researchers should consider the impact of preinjury depression on the recovery process to provide at-risk patients adequate treatment soon after injury.