Flexible Delivery of CPT in First Responders and Veterans: The Role of Explicit Case Formulation

Reginald D.V. Nixon, David Forbes, & Tara E. Galovski

October 7, 2025

Posttraumatic stress disorder (PTSD) is a debilitating and multifaceted disorder often accompanied by co-occurring physical and psychiatric problems. Numerous evidence-based psychotherapies (EBPs), including Cognitive Processing Therapy (CPT; Resick, Monson, & Chard, 2024) a first-line PTSD treatment, exist to treat PTSD. Increasingly, research has focused on how to improve uptake, delivery and effectiveness of first-line PTSD treatments. Currently, response rates to EBPs for PTSD vary (Cusack et al., 2016; Semmlinger et al., 2024), with symptoms remaining at post-treatment for some clients and Semmlinger et al. have estimated a nonresponse rate of 39%; in addition, disengagement rates are not low (~20.9%; Varker et al., 2021). These rates are likely exacerbated by factors that make it challenging for clinicians to identify risk of dropout/disengagement, as well as drift from evidence-based protocols due to perceived inflexibility for ‘real-world’ client comorbidities. Certain subpopulations – active-duty military personnel, veterans, and first responders – experience PTSD at a higher rate to the general population and may face unique barriers to treatment. While these populations respond to EBPs, observable outcomes are often more modest compared to civilian populations. In addition, challenges to optimal therapy outcomes (e.g., avoidance of trauma reminders, including therapy, problematic alcohol use, suicidal ideation and impairment in social functioning) can present further challenges for individual treatment effectiveness.

In response to these clinician and client-level issues, research has focussed on increasing existing PTSD treatment flexibility. Previously, research has augmented CPT to address comorbidities, showing its ability to be both a flexible and effective treatment. Specifically, case formulation has been used within CPT to assist clinicians to deviate from treatment manuals and address client comorbidity (Galovski et al., 2020).

Applying explicit case formulation (CF) with first responders and veterans

Our recent study (Nixon et al., 2025), examined integrating explicit case formulation (CF) into CPT (thus termed CPT-CF). This collaborative approach, enhanced through the use of a therapeutic assessment letter, aimed to boost engagement, clarify treatment goals, and guide deviations from standard CPT to address comorbidity and treatment barriers. 29 participants (meeting DSM-5-TR PTSD diagnostic criteria) – many presenting with comorbid mood, anxiety or substance use disorders – received up to 25 weekly CPT-CF sessions.

23 participants (82%) completed treatment. Results demonstrated significant and substantial reduction in both PTSD (clinician-rated and self-report) and depressive (self-report) symptoms, with marked improvements in quality of life, sleep and trauma-related beliefs. Clinical gains were maintained at 3-month follow-up, with majority meeting good end-stage functioning for PTSD, and no participants meeting the criteria for PTSD. There were moderate-to-major deviations from CPT protocol for seven participants. Protocol deviations included integration of behavioural experiments, substantial behavioural activation for depression, strategies for problematic alcohol use, in-vivo exposure, enhancing motivation, and addressing self-harm and suicidality. Importantly, these participants demonstrated similar outcomes to those who did not require deviations from standard CPT – indicating that judiciously undertaken divergences did not derail treatment and can contribute to successful outcomes, particularly in the presence of comorbidities. Generally, participants also reported an increase in client-clinician working alliance across treatment, and consistent ratings of therapy credibility and usefulness of the CF approach.

Implications and Future Directions

These findings replicate and extend previous research in enhanced CPT for civilian population and are noteworthy given the (a) predominantly male first responder sample, and (b) high exposure to traumatic events (more than 20% of sample reporting 20 or more exposures to sudden or violent death throughout employment). These populations often report an attenuated response to PTSD treatments, including CPT.

The current study suggests that integrating CF into CPT may enhance effectiveness for first responders and veterans by clinically guiding manual deviations where needed. Further, future research should consider examining CF’s potential to identify such deviations earlier in treatment. Together, with prior findings, the current study supports ongoing investigation of CF in CPT, particularly through randomised control trials (see study design by Galovski et al., 2024). More broadly, further evaluation of augmenting or enhancing PTSD treatments for trauma populations is warranted.

Discussion Questions

1. What are the potential ongoing benefits/outcomes to including explicit case formulation in CPT treatment?
2. How does the current study extend our understanding and application of CPT in clinical settings?
3. How might the demonstrated flexibility of CPT-CF influence approaches to other manualised treatments for PTSD?

Reference Article

Read the full article here in Journal of Traumatic Stress: 

Nixon RDV, Forbes D, Galovski TE. Cognitive processing therapy for posttraumatic stress disorder in first responders and veterans: Flexing the approach with explicit case formulation. J Trauma Stress. 2025 Sep 14. doi: 10.1002/jts.70005. Epub ahead of print. PMID: 40947656.

About the Authors

References

Cusack, K., Jonas, D. E., Forneris, C. A., Wines, C., Sonis, J., Middleton, J. C., Feltner, C., Brownley, K. A., Olmsted, K. R., Greenblatt, A., Weil, A., & Gaynes, B. N. (2016). Psychological treatments for adults with posttraumatic stress disorder: A systematic review and meta-analysis. Clinical Psychology Review, 43(1), 128–141. https://doi.org/10.1016/j.cpr.2015.10.003