Trauma patients who tested positive for THC were 66% more likely to screen positive for post-traumatic stress symptoms

THC-positive patients were more likely to screen positive on the Posttraumatic Adjustment Scale (19.6% vs. 13.2%, p = 0.001). After adjusting for age, sex, injury severity, assault mechanism, polysubstance use, ICU admission, and complications, THC use remained independently associated with a positive PAS screen (OR 1.66, 95% CI 1.23-2.24).

Retrospective cohort study at a Level 1 trauma center (January 2023 to December 2024). 1,960 adult trauma patients who completed inpatient PAS screening were included. THC use was identified via admission urine drug screen. Multivariable logistic regression adjusted for demographic and clinical confounders.

This raises questions about whether pre-existing cannabis use is a marker for psychological vulnerability to trauma. If THC users are at higher risk for post-traumatic distress, they may benefit from enhanced mental health screening after traumatic injuries.

Cannabis is often discussed as a potential treatment for PTSD, but this study suggests that pre-trauma cannabis use may actually signal heightened vulnerability. The direction of the relationship matters: is cannabis a risk factor, a marker for pre-existing vulnerability, or both?

Retrospective design cannot establish causation. Urine drug screen detects recent use, not use at time of trauma. No information on frequency, dose, or reason for cannabis use. PAS is a screening tool, not a PTSD diagnosis. Single center.