Aims: The 10-site Prescription Opioid Addiction Treatment Study, conducted in the NIDA Clinical Trials Network, examined different lengths of buprenorphine-naloxone (bup-nx) plus medical management, with or without additional counseling, for patients dependent upon prescription opioids. Among patients (N=360) receiving 12 weeks of bup-nx stabilization, 49% achieved successful opioid use outcomes at week 12. The aim of this secondary analysis is to examine the ability to predict outcome (and thus potentially alter the treatment) based on early (weeks 1–4) treatment response. (Source: Drug and Alcohol Dependence)