Cognitive behavioral treatments tend to be the most highly efficacious treatments for PTSD. Cognitive Processing Therapy (CPT) is one such treatment that has garnered a significant amount of empirical support, with a recent metaanalysis showing it was the most effective treatment for PTSD, typically yielding a 50% or larger reduction in PTSD symptoms from pre- to posttreatment. Redutions in PTSD symptoms are similar in magnitude when CPT is delivered in a virtual or telehealth format as compared to face-to-face delivery. Long-term follow-up studies conducted in nonmilitary samples also suggest the beneficial effects of CPT endure for up to 10 years posttreatment. Clinical improvement and recovery rates tend to be higher among patients who complete CPT compared to those that drop out of treatment early. Data also suggest that PTSD outcomes are moderated by session frequency, such that CPT sessions spaced closer together yield better effects than CPT sessions that are spaced further apart.

In addition to reducing PTSD symptoms, recent studies indicate CPT is also associated with significant short-term reduction in suicide ideation, potentially due to its effects on PTSD and depression symptom severity. In some studies, suicide ideation increased in severity again several months after the conclusion of therapy, however, suggesting a period of increased vulnerability for suicide. Enhancing CPT with procedures that have been shown to significantly reduce suicidal thoughts and behaviors could serve to further reduce suicide risk during and after treatment completion. One such procedure is the crisis response plan (CRP), a collaborative, patient-centered intervention that is typically handwritten on an index cards and focuses on several key components: (1) warning signs, (2) self-regulatory strategies, (3) reasons for living, (4) sources of social support, and (5) professional and crisis services. In a randomized clinical trial previously conducted by our team, acutely suicidal patients who received a CRP showed significantly faster declines in suicide ideation and were 76% less likely to attempt suicide during the 6-month follow-up as compared to patients who received mental health treatment as usual.

In the present study, the investigators aim to determine if the addition of a CRP with CPT will lead to faster reductions in suicide ideation and prevent the recurrence of suicide ideation during follow-up as compared to the standard provision of CPT. To achieve this, this study includes a two-arm, double blind parallel randomized clinical trial. The investigators will enroll 150 military personnel and veterans who meet full diagnostic criteria for PTSD (i.e., having 4 of 4 symptom criteria at or above threshold levels) or subthreshold PTSD (i.e., having 3 of 4 symptom criteria at or above threshold levels). All participants will receive 10-12 sessions of CPT, administered on a daily basis for two consecutive weeks. The investigators will assess suicide ideation, suicide attempts, and psychological symptom severity for up to one year post-treatment. Our primary hypothesis is that the combination of CRP and CPT will result in larger reductions in suicide ideation than CPT alone.