Posttrauma Benzodiazepine Use and Subsequent PTSD: A Population-Wide Analysis Following Extreme Traumatic Exposure.

Objective

To examine whether benzodiazepine use within 30 days after mass trauma increases posttraumatic stress disorder (PTSD) risk and whether timing or persistence of use modifies this association.

Methods

This retrospective cohort study leveraged 3 advantages: large-scale clinical dataset (∼4 million individuals), unprecedented collective exposure to trauma, and novel methodological approach addressing severity bias. Using data from Clalit Health Services (covering ∼54% of the population), we identified 15,570 benzodiazepine-naïve adults who received a new benzodiazepine prescription within 30 days of index date (October 7, 2023). Medication exposure was defined by prescription redemption (none, early ≤7 days, late 8-30 days) and by persistence based on refill behavior. Incident PTSD diagnoses (ICD-10 F43.1) were identified over 12 months. Cox proportional hazards models estimated hazard ratios (HRs), adjusting for demographic characteristics and psychiatric history.

Results

Overall PTSD incidence was 5.0% (773/15,570). Twelve-month risk was 5.2% for nonpurchasers, 4.7% for early purchasers, and 5.0% for late purchasers. Fully adjusted models showed no increased risk with early (HR=0.98, 95% CI=0.80-1.20) or late (HR=1.11, 95% CI=0.94-1.31) purchase. Persistent users had elevated risk (HR=1.60, 95% CI=1.14-2.25 and HR=2.07, 95% CI=1.60-2.68), whereas discontinued users did not. Among Gaza border residents (n=238), both early (HR=0.52, 95% CI=0.31-0.88) and late (HR=0.62, 95% CI=0.38-0.98) purchasers had lower PTSD risk than nonpurchasers.

Conclusions

In this naturalistic setting of mass trauma, short-term benzodiazepine use during 30 days postexposure was not associated with increased 12 month PTSD risk. Among highly trauma-exposed individuals, it was linked to reduced risk at 12 months. These findings challenge current caution against early benzodiazepine use in the immediate aftermath of trauma.