Prescription Patterns in Canadian Operational Stress Injury Clinics

To examine pharmacotherapy prescribing patterns for posttraumatic stress disorder (PTSD) across Canadian operational stress injury (OSI) clinics and evaluate their alignment with guideline-recommended treatment principles. Although prescribing practices for PTSD have been examined in other settings, evidence from Canada's specialized OSI clinic network remains limited. Additionally, little is known about how patient clinical characteristics and complexity influence prescribing decisions within military and veteran populations receiving specialized PTSD care. A 2-part, nationwide survey of psychiatrists practicing in Canadian OSI clinics was conducted. Part 1 assessed prescriber characteristics and factors influencing medication selection. Part 2 captured de-identified patient-level data on demographics, PTSD history, comorbidities, concurrent psychotherapy, and prescribed medications. Descriptive and comparative analyses examined prescribing patterns, polypharmacy, coprescribed medication classes, and variation across clinic sites. Twenty psychiatrists contributed data on 438 patients with PTSD. Patients had long-standing illness (mean duration, 8.2 years), high psychiatric and medical comorbidity, and extensive pharmacotherapy exposure. Nearly all patients (98.6%) were prescribed at least 1 medication for PTSD, with an average of 3 PTSD-related medications per patient. Selective serotonin reuptake inhibitors and serotonin-norepinephrine reuptake inhibitors were commonly prescribed and frequently formed the foundation of treatment, consistent with guideline recommendations. However, adjunctive use of hypnotics, antiadrenergic agents, antipsychotics, and benzodiazepines was common, reflecting symptom-targeted prescribing and frequent polypharmacy. Substantial variability in medication selection and class use was observed across clinic sites. Pharmacotherapy for PTSD in Canadian OSI clinics is characterized by frequent polypharmacy and marked intersite variability, despite general alignment with guideline-recommended first-line agents. These findings highlight the challenges of applying guideline-based care to patients with chronic, complex PTSD and underscore the need for pragmatic, clinician-informed guidance and further research on sequenced and combined pharmacologic strategies. .