Project Description: The aims of the Parent Grant (4UH3DA051241; PI Witkiewitz) are to conduct a randomized clinical trial to assess the efficacy of two empirically supported interventions: Acceptance and Commitment Therapy for chronic pain and Mindfulness Based Relapse Prevention for opioid use disorder (OUD). Efficacy will be assessed by examining pain interference and opioid use outcomes after three months of active treatment, as well as at 6 and 12 month follow-ups. Secondary outcomes, including depression, pain- related fears, and opioid misuse risk, will also be assessed at these same follow-ups. The study will also examine the relation between within-treatment changes in treatment mechanisms, including pain acceptance, engagement in values-based action, and opioid craving, and changes at post- treatment and follow-up. Data analysis will implement innovative statistical techniques to examine differences between treatment groups on outcome measures using a mixed-effects model with fixed effects of treatment and random effects of time. The results will potential enhance current clinical practice guidelines by developing unique psychosocial treatment that simultaneously addresses pain interference and opioid-related problems in an integrated format. The specific aims of the supplement are to (1) Identify psychosocial correlates of internalized stigma among patients with chronic pain and OUD (n = 160) who are receiving buprenorphine through a VA-based co- occurring disorders clinic; (2) Assess the impact of internalized stigma on treatment adherence among patients with co-occurring chronic pain and OUD; (3) Assess the impact of ACT+MBRP on reducing internalized stigma among patients with co-occurring chronic pain and OUD. These specific aims will identify psychosocial correlates of internalized stigma, evaluate the effects of internalized stigma on treatment adherence, and examine the effects of integrated treatment on reducing internalized stigma.

Project Narrative This study seeks to provide training to Dr. Verlin Joseph to better understand how internalized stigma affects treatment adherence among veterans with chronic pain receiving treatment for opioid use disorder. This supplement will simultaneously train the applicant in integrated treatment for chronic pain and opioid use disorder and in longitudinal statistical modeling techniques. The results from this project will identify biopsychosocial correlates of internalized stigma that may ultimately improve treatment adherence and decrease the public health burden of opioid use disorder.