Severe Traumatic Brain Injury Outcomes in Patients with Premorbid Psychiatric Illness

Objective: Individuals with psychiatric illnesses (PIs) have increased rates of traumatic brain injury (TBI). Nonetheless, the influence of underlying PI on TBI outcomes is poorly understood. Methods: We analyzed the medical records of 633 adult-severe TBI patients admitted to our institution between 2010 and 2021. We identified patients with premorbid PI (Psych (+) group, n = 129) and a subset with only a substance use disorder (SUD (+) group, n = 60) and compared them to patients without PI (Psych (−) group, n = 480). Outcome measures included discharge Glasgow Coma Scale (GCS), length of stay, in-hospital survival, and Glasgow Outcome Scale-Extended (GOS-E). Results: The Psych (+) group had increased in-hospital survival (69.8% vs. 55.0%, P = 0.003) and fewer patients with severe (3–8) discharge-GCS (28.7% vs. 46.0%, P < 0.001). The SUD (+) group had increased in-hospital survival (70.0% vs. 55.0%, P = 0.028) and fewer patients with severe discharge-GCS (28.3% vs. 46.0%, P = 0.009). However, the Psych (+) (21.0 vs. 10.0 days, P < 0.001) and SUD (+) (16.0 v. 10.0 days, P = 0.011) groups had longer length of stay. The Psych (+) group had a higher mean GOS-E at discharge (2.7 vs. 2.4, P = 0.004), 6-months (3.8 vs. 3.0, P = 0.006) and 1-year (3.4 vs. 2.3, P = 0.027). The SUD (+) group also had a higher mean GOS-E at discharge (2.8 vs. 2.4, P = 0.034), six months (3.8 vs. 3.0, P = 0.035), and one year (3.5 vs. 2.3, P = 0.008). Additionally, there were no significant differences in injury severity or computed tomography scan findings. Conclusions: Individuals with PI and SUD appeared to have better outcomes but more complicated hospital stays following severe TBI. Future studies should investigate the mechanisms underlying these outcomes.