Background and Significance: Posttraumatic stress disorder (PTSD) and substance use disorder (SUD) comorbidity is common. The Veterans Affairs (VA)/Department of Defense Clinical Practice Guideline for PTSD strongly recommends providing guideline-concurrent care for PTSD alongside SUD treatment, but there is insufficient evidence about which guideline-recommended treatments for PTSD work best in this population. Trauma-focused therapy (TFT) is a frontline treatment approach; yet its effectiveness is less well-established among patients with co-occurring SUD, and TFT dropout rates are uniquely high in this population. Multiple guidelines suggest non-trauma-focused treatment (NTFT) as a second-line treatment approach for PTSD; higher completion rates for some NTFT (e.g., Present Centered Therapy) may make this strategy particularly effective for those with comorbid SUD. Despite providers' desire for an NTFT option for patients with PTSD/SUD, no guideline-recommended NTFTs have been evaluated in those with the comorbidity

Study Aims: Our long-term objective is to improve the lives of patients with co-occurring PTSD and SUD. To meet this objective, we will conduct a pragmatic randomized clinical trial that will yield decisive data regarding the comparative effectiveness of two evidence-based approaches for the treatment of PTSD in this understudied patient population: trauma-focused and non-trauma-focused psychotherapy. The major aims are: (1) Determine whether TFT differs at a clinically-meaningful magnitude from NTFT in its effects on posttreatment PTSD symptoms among patients with co-occurring PTSD and SUD (2) Determine whether patients with co-occurring PTSD and SUD randomized to TFT drop out of PTSD treatment more often than those randomized to NTFT, and (3) Determine if TFT differs at a clinically-meaningful level from NTFT in PTSD symptom reduction and number of PTSD therapy sessions attended in patients with varying (a) levels of baseline SUD severity, (b) classes of misused substances, and (c) treatment preferences.

Study Description: We propose a prospective, pragmatic randomized comparative effectiveness trial at 14 VA Medical Center sites (11 confirmed). Randomization will occur at the patient level and will assign participants to either (1) TFT (Prolonged Exposure or Cognitive Processing Therapy) or 2) NTFT (Present Centered Therapy). All participants will also receive concurrent SUD treatment-as-usual. Participants will complete self-report measures and a clinician-administered interview pretreatment, posttreatment, and six-months posttreatment. 420 participants (210 per arm) will be veterans seeking outpatient SUD treatment in an enrolled clinic who meet DSM-5 criteria for a current SUD and PTSD. The sample will be diverse in sex, race, age, and geography. Main outcomes will be PTSD symptom severity measured by the Clinician Administered PTSD Scale for DSM-5 (CAPS-5), and PTSD treatment dropout (dichotomous indicator of completion of all PTSD treatment sessions). Major Aim 1 will be tested using a linear mixed model using study intervention, assessment point, and their interaction as fixed effects and including random effects for participant, clinician, and study site. Major Aim 2 will be testing using a random effects logistic regression of therapy retention on intervention and baseline CAPS incorporating random effects for clinician and site.