Shaping cocaine abstinence by successive approximation.
Cocaine-using methadone-maintenance patients were randomized to standard contingency management (abstinence group, n = 49) or to a contingency designed to increase contact with reinforcers (shaping group, n = 46). For 8 weeks, both groups earned escalating-value vouchers based on thrice-weekly urinalyses: The abstinence group earned vouchers for cocaine-negative urines only; the shaping group earned vouchers for each urine specimen with a 25% or more decrease in cocaine metabolite (first 3 weeks) and then for negative urines only (last 5 weeks). Cocaine use was lower in the shaping group, but only in the last 5 weeks, when the response requirement was identical. Thus, the shaping contingency appeared to better prepare patients for abstinence. A 2nd phase of the study showed that abstinence induced by escalating-value vouchers can be maintained by a nonescalating schedule, suggesting that contingency management can be practical as a maintenance treatment.
Preston
K L
KL
Intramural Research Program, National Institute on Drug Abuse, Baltimore, Maryland 21224, USA. kpreston@intra.nida.nih.gov
Umbricht
A
A
Wong
C J
CJ
Epstein
D H
DH
D000328:Adult; D001521:Behavior Therapy; D019970:Cocaine-Related Disorders / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D008297:Male; D008691:Methadone / Q000627:therapeutic use; D008875:Middle Aged; D009042:Motivation; D009293:Opioid-Related Disorders / Q000534:rehabilitation; D012055:Reinforcement Schedule; D015813:Substance Abuse Detection; D014040:Token Economy
D008691:Methadone