Therapy Dose Mediates the Relationship Between Buprenorphine/Naloxone and Opioid Treatment Outcomes in Youth Receiving Medication for Opioid Use Disorder Treatment.

Abstract

Evidence-based interventions for treating opioid use disorder (OUD) in youth are limited and little is known about specific and general mechanisms of OUD treatments and how they promote abstinence. The present study used data from the NIDA-CTN-0010 trial to evaluate the mediating effects of psychosocial treatment-related variables (therapy dose and therapeutic alliance) on end-of-treatment opioid abstinence in a sample of youth with OUD (n = 152, 40% female, mean age = 19.7 years) randomized to receive either 12-weeks of treatment with Bup/Nal ("Bup-Nal") or up to 2 weeks of Bup/Nal detoxification ("Detox") with both treatment arms receiving weekly individual and group drug counseling ± family therapy. Participants in the Bup-Nal group attended more therapy sessions (16 vs 6 sessions), had increased therapeutic alliance at week-4, and had less opioid use by week-12 compared to those in the Detox group. In both treatment arms, youth who attended more therapy sessions were less likely to have a week-12 opioid positive urine. In a multiple mediator model, therapy dose mediated the association between treatment arm and opioid abstinence. These findings provide preliminary support for a "dose-response" effect of addiction-focused therapy on abstinence in youth OUD. Further, the results identified a mediating effect of therapy dose on the relationship between treatment assignment and opioid treatment outcomes, suggesting that extended Bup-Nal treatment may enhance abstinence, in part, through a mechanism of therapy facilitation, by increasing therapy dose during treatment.