Background A subset of persons with mild traumatic brain injury (mTBI) experience long-term difficulties. Preinjury stress has been hypothesised to play a role in long-term maintenance of symptoms.

Objective To investigate the predictive ability of preinjury stressful life events and post-traumatic stress symptoms to health-related quality of life and emotional distress after mTBI.

Methods Within 2 weeks of injury, 186 participants with mTBI who were admitted to an emergency centre completed an interview and questionnaires regarding preinjury functioning, including the Stressful Life Events Questionnaire and the Post-Traumatic Stress Disorder Checklist. Outcomes were assessed at 3 months after injury and included the depression and anxiety subscales of the Brief Symptom Inventory, and the physical and mental component scores of the 36-item Short-Form Health Survey (SF-36). The incidence and type of stressful life events were reported. Hierarchical regression analyses were used to determine the predictive utility of Stressful Life Events Questionnaire and Post-Traumatic Stress Disorder Checklist after controlling for age, injury severity (complicated versus uncomplicated mild) and preinjury depression.

Results Several potentially life-altering stressful events were endorsed by at least 25% of participants as having been experienced prior to injury. The incidence of stressful life events was a significant predictor of all four outcome variables. History of post-traumatic stress symptoms was predictive of scores on the SF-36 mental health component.

Conclusions A history of stressful events may predispose persons with mTBI to have poor outcomes. History of stress should be assessed during the early stages after mTBI to help identify those who could benefit from therapies to assist with adjustment and maximise recovery.