Open Pilot Trial of Adapted Cognitive Processing Therapy for Comorbid PTSD and Opioid Use Disorder

Inclusion Criteria: * Over the age of 18 * Regular syringe services program attendance (ex. at least 4 visits in the past month) * Meeting DSM-5 opioid use disorder criteria * Having been prescribed a medication for opioid use disorder in the past 30 days at the time of screening * Criterion A event as measured by the Life Events Checklist for DSM-5 (LEC-5) * PTSD symptoms at the level of a PTSD diagnosis as evidenced by a score of 31 or greater on the PTSD Checklist for DSM-5 (PCL-5) * Ability to understand English * Consent to have assessment interviews audio recorded and teletherapy sessions video recorded for research purposes * Ability to provide informed consent Exclusion Criteria: * High risk for suicidal thoughts and/or behaviors that would make participation dangerous, as measured by the Columbia Suicide Severity Rating Scale Lifetime-Recent Screen * Meeting DSM-5 criteria for a current psychotic or bipolar disorder. * Cognitive impairment liable to interfere with completion of study procedures * Currently receiving trauma-focused psychotherapy (i.e. Prolonged Exposure, Cognitive Processing Therapy).