Somatic Symptom Disorder After Mild Traumatic Brain Injury.

OBJECTIVE

Mild traumatic brain injury (mTBI) may be a common precipitant of Somatic Symptom Disorder (SSD). This study examined the prevalence, correlates, predictors, and functional impact of SSD after mTBI.

SETTING

Follow up of patients recruited from emergency departments and urgent care centers.

PARTICIPANTS

Adults with mTBI (N = 476).

DESIGN

Secondary analysis of a clinical trial (Clinicaltrials.gov NCT04704037).

MAIN MEASURES: Early illness beliefs (Illness Perceptions Questionnaire-Revised; IPQ-R) were assessed ~2 weeks after mTBI and outcomes were assessed at 6 months post-injury, including SSD symptoms (Somatic Symptom Disorder-B Criteria Scale; SSD-12), post-concussion symptoms (Rivermead Post Concussion Symptoms Questionnaire; RPQ), disability (World Health Organization Disability Assessment Schedule; WHODAS), and psychiatric diagnoses (MINI Neuropsychiatric Inventory). SSD diagnosis was operationalized as having persistent symptoms and SSD-12 ≥ 16 (≥23 in sensitivity analyses).

RESULTS

15-27% of the sample met criteria for SSD at 6 months post-injury. Participants with SSD reported more pain and post-concussion symptoms, and were more likely to have comorbid Major Depressive Disorder (OR = 9.1, 95% CI = 5.3, 16.2) and at least 1 anxiety disorder (OR = 5.6, 95% CI = 3.6-8.8) compared to those without SSD. Early illness beliefs, specifically that mTBI has serious life consequences (OR = 1.2, 95% CI = 1.1-1.3) and causes distress (OR = 1.1, 95% CI = 1.0-1.2), were associated with later SSD. SSD symptoms contributed to prediction of global functional disability (WHODAS) over and above post-concussion symptom severity (RPQ; ΔDeviance = 0.22, P < .001).

CONCLUSIONS

SSD after mTBI is associated with an increased burden of symptoms, comorbidity, and disability. Early identification of at-risk patients appears feasible. SSD may be a useful framework for conceptualizing poor outcome from mTBI in patients with prominent psychological distress and guiding rehabilitation.