Contingent reinforcement of abstinence with individuals abusing cocaine and marijuana.
Level 4 - case-series / case-control
Small case series / within-subject behavioral intervention study with no control group
PubMed 1797769 · doi:10.1901/jaba.1991.24-657
What was done
Two men diagnosed with cocaine dependence received a behavioral treatment combining contingency management (reinforcement contingent on submitting drug-free urine specimens) and the community reinforcement approach. Treatment proceeded across sequential phases: initial reinforcement contingent on cocaine-free urine paired with twice-weekly behavior therapy; reduced reinforcement magnitude with once-weekly therapy; and a modified contingency requiring specimens to be free of both cocaine and marijuana. Follow-up evaluations occurred at 1 and 5 months.
What was found
Reinforcement contingent solely on cocaine-free urine achieved almost complete cocaine abstinence while regular marijuana use continued. Adding marijuana abstinence to the contingency produced an abrupt increase in marijuana abstinence while maintaining cocaine abstinence. At 1- and 5-month follow-ups, cocaine abstinence continued, but marijuana smoking resumed. The abstract does not report numeric percentages or specimen counts.
Why it matters
This study demonstrates that contingency management reinforcement may be substance-specific in polydrug users, showing that explicit contingencies are needed for each substance rather than abstinence generalizing across drugs.
Limits
The sample size is extremely small (n = 2), both subjects were male, and there was no control group. Long-term abstinence was not sustained for marijuana, and exact quantitative data are absent from the abstract.
Cited by
- supports Psychologist Stephen Higgins pioneered the use of contingency management reinforcement protocols for treating cocaine addiction.