Background/objective: The study explored whether premorbid substance use disorder (SUD) predicts acute traumatic brain injury (TBI) outcomes.
Methods: 143 participants with moderate (34.2%) and severe (65.8%) TBI were enrolled at two Level 1 trauma center inpatient brain injury rehabilitation units. Acute outcomes were measured with the Disability Rating Scale (DRS), the FIMTM; self and informant ratings of the Patient Competency Rating Scale (PCRS); self and family rating of the Frontal Systems Behavioral Scale (FrSBe), and the Neurobehavioral Rating Scale-Revised (NRS-R).
Results: Hierarchical linear modeling revealed that SUD history significantly predicted trajectories of PCRS clinician ratings, PCRS self-family and PCRS self-clinician discrepancy scores, and more negative FrSBE family ratings. These findings indicate comparatively greater post-injury executive functions (EF) impairments, particularly self-awareness (SA) of injury-related deficits, for those with SUD history. No significant SUD*time interaction effect was found for FIM or NRS-R scores.
Conclusions: SUD history and TBI are associated with impaired SA and EF but their co-occurrence is not a consistent predictor of acute post-injury functional outcomes. Pre-morbid patient characteristics and rater expectations and biases may moderate associations between SA and recovery after TBI.
Keywords: Traumatic brain injury; rehabilitation; substance use disorder.