Opioid-Related DisordersBuprenorphineOpiate Substitution TreatmentMethadoneNarcoticsPsychoses, AlcoholicAnalgesics, OpioidAlcoholismNarcotic AntagonistsHeroin DependenceSubstance Abuse Treatment CentersNaloxoneReceptors, Opioid, muReceptors, OpioidNaltrexoneSubstance Withdrawal SyndromeReceptors, Opioid, deltaReceptors, Opioid, kappaOpioid PeptidesTreatment Outcome