title: Randomized trial of prize-based reinforcement density for simultaneous abstinence from cocaine and heroin.
abstract: To examine the effect of reinforcer density in prize-based abstinence reinforcement, heroin/cocaine users (N = 116) in methadone maintenance (100 mg/day) were randomly assigned to a noncontingent control group (NonC) or to 1 of 3 groups that earned prize draws for abstinence: manual drawing with standard prize density (MS) or computerized drawing with standard (CS) or high (CH) density. Probabilities (prizes/draw) were standard (50%) and high (78%); prize density was double blind. Mean prize values were CH, $286; CS, $167; MS, $139; and NonC, $171. Outcomes were % opioid/cocaine-negative urines during the 12-week intervention and then 8 weeks postintervention as well as diagnosis of dependence up to 6 months poststudy. CH had significantly more negative specimens than did NonC during intervention and had more than all groups during postintervention treatment: Mean % negative (95% confidence interval) during postintervention treatment adjusted for baseline drug use and dropout were CH, 55% (14%-90%); CS, 7% (1%-27%); MS, 4% (1%-12%); and NonC, 3% (1%-10%). Current cocaine dependence diagnoses after treatment were significantly lower in contingent compared with noncontingent groups. Computerized drawing with higher-density prizes enhanced reduction of cocaine use; abstinence reinforcement had long-term therapeutic benefits.
authors: Treatment Section, Clinical Pharmacology and Therapeutics Branch, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institute of Health (NIH), MD, USA. ghitzau@intra.nida.nih.gov
authors: Udi E
authors: UE
authors: Ghitza
authors: David H
authors: DH
authors: Epstein
authors: John
authors: J
authors: Schmittner
authors: Massoud
authors: M
authors: Vahabzadeh
authors: Jia-Ling
authors: JL
authors: Lin
authors: Kenzie L
authors: KL
authors: Preston
mesh_terms: D000328:Adult; D019970:Cocaine-Related Disorders / Q000453:epidemiology / Q000534:rehabilitation*; D015897:Comorbidity; D004311:Double-Blind Method; D005260:Female; D006556:Heroin Dependence / Q000453:epidemiology / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008691:Methadone / Q000627:therapeutic use; D008875:Middle Aged; D009042:Motivation; D009294:Narcotics / Q000627:therapeutic use; D012055:Reinforcement Schedule; D012201:Reward; D012984:Software; D013813:Therapy, Computer-Assisted; D014040:Token Economy
chemical_list: D009294:Narcotics; D008691:Methadone