Active rTMS for Opioid Use Disorder

In this research study the investigators will work with 80-participants with opioid use disorder who are starting treatment with the medication buprenorphine and are trying to quit using opioids. The investigators are trying to learn two things: 1. Can an MRI brain marker be used to predict which participants will be successful in quitting opioids with buprenorphine? 2. Does adjunctive treatment with repetitive Transcranial Magnetic Stimulation (rTMS) help people quit using opioids more than a sham (placebo) version of rTMS? In order to complete the study the investigators will ask participants to: * Complete an MRI within 5-days of starting buprenorphine and again after they are on a full stable dose 1-3 weeks later. * Undergo study-treatment with 50-sessions of either real or placebo rTMS in as little as 1-week (10-sessions-per-day for five days) or as long as over 6-weeks. * Meet with the investigators once per week over the following 12-weeks to see if the participants have been able to quit using opioids over that time.