title: Promoting abstinence from cocaine and heroin with a methadone dose increase and a novel contingency.
abstract: To test whether a combination of contingency management and methadone dose increase would promote abstinence from heroin and cocaine, we conducted a randomized controlled trial using a 2 x 3 (dosexcontingency) factorial design in which dose assignment was double-blind. Participants were 252 heroin- and cocaine-abusing outpatients on methadone maintenance. They were randomly assigned to methadone dose (70 or 100mg/day, double-blind) and voucher condition (noncontingent, contingent on cocaine-negative urines, or "split"). The "split" contingency was a novel contingency that reinforced abstinence from either drug while doubly reinforcing simultaneous abstinence from both: the total value of incentives was "split" between drugs to contain costs. The main outcome measures were percentages of urine specimens negative for heroin, cocaine, and both simultaneously; these were monitored during a 5-week baseline of standard treatment (to determine study eligibility), a 12-week intervention, and a 10-week maintenance phase (to examine intervention effects in return-to-baseline conditions). DSM-IV criteria for ongoing drug dependence were assessed at study exit. Urine-screen results showed that the methadone dose increase reduced heroin use but not cocaine use. The split 100mg group was the only group to achieve a longer duration of simultaneous negatives than its same-dose noncontingent control group. The frequency of DSM-IV opiate and cocaine dependence diagnoses decreased in the active intervention groups. For a split contingency to promote simultaneous abstinence from cocaine and heroin, a relatively high dose of methadone appears necessary but not sufficient; an increase in overall incentive amount may also be required.
authors.affiliation: Treatment Section, Clinical Pharmacology & Therapeutics Branch, Intramural Research Branch of the National Institute on Drug Abuse, 251 Bayview Blvd., Suite 200, Baltimore, MD 21224, USA. depstein@intra.nida.nih.gov
authors.forename: David H
authors.initials: DH
authors.lastname: Epstein
authors.forename: John
authors.initials: J
authors.lastname: Schmittner
authors.forename: Annie
authors.initials: A
authors.lastname: Umbricht
authors.forename: Jennifer R
authors.initials: JR
authors.lastname: Schroeder
authors.forename: Eric T
authors.initials: ET
authors.lastname: Moolchan
authors.forename: Kenzie L
authors.initials: KL
authors.lastname: Preston
mesh_terms: D000328:Adult; D001944:Breath Tests; D019970:Cocaine-Related Disorders / Q000523:psychology / Q000534:rehabilitation* / Q000652:urine; D003376:Counseling; D003627:Data Interpretation, Statistical; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006293:Health Promotion; D006556:Heroin Dependence / Q000523:psychology / Q000534:rehabilitation* / Q000652:urine; D006801:Humans; D008297:Male; D008691:Methadone / Q000008:administration & dosage / Q000627:therapeutic use*; D008875:Middle Aged; D009042:Motivation; D009294:Narcotics / Q000008:administration & dosage / Q000627:therapeutic use*; D011569:Psychiatric Status Rating Scales; D011788:Quality of Life; D012959:Socioeconomic Factors; D015813:Substance Abuse Detection; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D009294:Narcotics; D008691:Methadone