Abuse potential Adult 1 Anxiety 1 Article 1 Buprenorphine 1 Craving 1 Female 1 Heroin Dependence 1 Humans 1 Hypoglycemic Agents 1 Male 1 Middle Aged 1 PPAR gamma 1 Pioglitazone 1 Reinforcement (Psychology) 1 Self Administration 1 Single-Blind Method 1 adult 1 antidiabetic agent 1 anxiety 1 association 1 buprenorphine 1 buprenorphine plus naloxone 1 controlled study 1 craving 1 diamorphine 1 drug craving 1 drug effect 1 drug efficacy 1 drug safety 1