Delivering Transcutaneous Auricular Neurostimulation to Improve Relapse Prevention in Opioid Use Disorder

This is a prospective, randomized, controlled, multi-center, clinical trial in which participants with a history of dependence on prescriptive or non-prescriptive opioids will be randomized 2:1 into one of four treatment groups during Phase I (acute detoxification, 7 days): 1. Group 1: Active tAN + placebo 2. Group 2: Active tAN + lofexidine 3. Group 3: Sham tAN + placebo 4. Group 4: Sham tAN + lofexidine Phase I will occur during the participant's treatment in a residential detox center. Participants will have the option to continue into Phase II of the trial at the conclusion of their stay in the residential detox treatment program. In Phase II, participants will be re-randomized 1:1 into one of two treatment groups and will return weekly for 90 days: 1. Group 1: Extended-release injectable naltrexone 2. Group 2: Active tAN + extended-release injectable naltrexone