Suicide Risk Among Veterans Who Receive Evidence-Based Therapy for Posttraumatic Stress Disorder.

Importance: Suicide rates are increased for veterans with posttraumatic stress disorder (PTSD). To inform Veterans Health Administration (VHA) operations, it is important to assess whether suicide risk for veterans differs by receipt of evidence-based treatments. Objective: To assess suicide risks among veterans in VHA care with new PTSD diagnoses who initiated or received an adequate course of evidence-based psychotherapy (cognitive processing therapy or prolonged exposure [CPT/PE]). Design, Setting, and Participants: This cohort study of veterans in VHA care evaluated suicide risk through 2020 for veterans with initial PTSD diagnoses during 2016-2019. Data collection and analyses were performed from March 22 to November 22, 2023. The population consisted of veterans who received an initial PTSD diagnosis (preceded by at least 12 months without a PTSD diagnosis) in 2016-2019. Exposures: Following the index PTSD diagnosis, receipt of a CPT/PE encounter and receipt of an adequate course of therapy (≥8 CPT/PE encounters). Main Outcome and Measure: Suicide mortality, per death certificate data from the Veterans Affairs/Department of Defense Mortality Data Repository. Results: Of the population-based sample of 847 217 US veterans, most were male (735 974 [86.9%]); the mean (SD) age was 50.1 (16.3) years. From initial PTSD diagnosis through 2020, there were 1552 suicides. Multivariable proportional hazards regression indicated that initiation of CPT/PE treatment was associated with a 23% lower suicide risk compared with those who did not initiate CPT/PE (hazard ratio [HR], 0.77; 95% CI, 0.59-0.99). Receipt of an adequate course was not associated with suicide (HR, 0.80; 95% CI, 0.55-1.18). Similar results were observed when limiting the cohort to those who received any psychotherapy (n = 552 742; CPT/PE initiation: HR, 0.73; 95% CI, 0.56-0.95; adequate course: HR, 0.77; 95% CI, 0.52-1.12). Conclusions and Relevance: The findings of this study suggest that, among veterans in VHA care with new PTSD diagnoses, CPT/PE initiation was associated with lower suicide risk. However, for those who initiated CPT/PE, receipt of 8 or more sessions was not associated with added benefit.