Overview Neurobiology of Opioid Dependence: 4 - 4 Status: Withdrawn Trial end date: 1998-01-01 Target enrollment: 0 Participant gender: All Summary The purpose of this study is to determine the effect of chronic naltrexone pre-treatment on the response to yohimbine in healthy volunteers. Phase: Phase 2Accepts Healthy Volunteers? No Details Lead Sponsor: Yale UniversityCollaborator: National Institute on Drug Abuse (NIDA)Treatments: Analgesics, OpioidNaltrexone Criteria Please contact site for information.