Original ArticlesTreatment for Individuals With Severe Mental Illness Who Use Illicit Drugs While Maintained on Methadone Mindfulness and Modification TherapyWupperman, Peggilee PhD*,†; Burns, Nancy MA, JD*; Pugach, Cameron P. MA‡; Edwards, Emily PhD*,†Author Information *Psychology Department, John Jay College, The Graduate Center at City University of New York, New York, New York †Psychiatry Department, Yale University School of Medicine, New Haven, Connecticut ‡Psychology Department, The University of North Carolina at Greensboro, Greensboro, North Carolina. Send reprint requests to Peggilee Wupperman, PhD, 524 W 59th St, Rm 10.63.20, New York, NY 10019. E-mail: email@example.com. Online date: October 30, 2019 The Journal of Nervous and Mental Disease: December 2019 - Volume 207 - Issue 12 - p 1005-1011 doi: 10.1097/NMD.0000000000001066 Buy Metrics Abstract Substantial research has noted the serious consequences of 1) co-occurring severe mental illness (SMI) and substance use disorders, and 2) use of illicit drugs while maintained on methadone for opioid dependence. However, treatment needs of individuals who meet both of the above criteria remain largely unmet. This pilot study investigated the feasibility and acceptability of a 12-week, transdiagnostic group therapy (mindfulness and modification therapy [MMT]) tailored for opioid-dependent individuals (N = 6) with SMI and illicit drug use. Retention was 83%. At posttreatment and 2-month follow-up, participants rated the treatment as highly helpful (9 of 10; 8.67 of 10, respectively), reported routinely practicing the guided-mindfulness exercises, and reported high confidence that they would continue to practice. Assessments revealed clinically meaningful decreases in reported days of illicit drug use at posttreatment and follow-up, with large effect sizes. Preliminary evidence suggests that MMT may be a feasible and acceptable therapy that may improve treatment engagement in this underserved population. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.