Effect of experimental analogs of contingency management treatment on cocaine seeking behavior

Abstract

Background: Contingency management (CM) treatment is effective for treating cocaine dependence but further mechanistic studies of its efficacy are warranted. This study aimed to determine whether: (a) higher vs. lower predictable money amounts ($3 vs. $1; analogs of standard voucher-based CM) increase cocaine demand elasticity; and (b) probabilistic amounts matched for expected value with the $3-predictable amount (50% chance of $6; 25% chance of $12; and 12.5% chance of $24; analogs of prize CM) similarly affect cocaine choice.

Methods: Each of 15 cocaine-dependent participants first completed a qualifying session to ensure that intranasal cocaine functioned as a reinforcer, then completed a 10-session, within-subject, randomized crossover study. During each of the 10 sessions, the participant responded on a progressive ratio schedule to earn units of cocaine (5-mg or 10-mg) and/or money (five monetary conditions above).

Results: During the reinforcement qualifying session (10-mg vs. 0-mg units; no money alternative), cocaine choice was high. The $3-predictable amount significantly decreased cocaine choice relative to both the $1-predictable amount and the qualifying session. Cocaine-choices in the probabilistic conditions were similar to the $3 predictable condition.

Conclusions: These findings indicate that CM interventions targeted at reducing cocaine self-administration are more likely to succeed with higher value non-drug reinforcement.

Trial registration: ClinicalTrials.gov NCT00946660.

Keywords: Cocaine; Contingency management; Magnitude; Probability; Self-administration.

Conflict of interest statement

Conflict of interest

The authors declare no conflicts of interest in relationship to performing this study.

Copyright © 2014. Published by Elsevier Ireland Ltd.

Figures

Fig. 1

Mean ± 1 SEM choice for cocaine 10-mg units in the reinforcement qualifying session (white bar) and for cocaine 10-mg or 5-mg units in each of the money alternative conditions. Non-shared letters above the error bars indicate significant differences in cocaine responding. Within each unit dose, $3 predictable significantly suppressed cocaine choice relative to $1 predictable amount. Within each unit dose, probabilistic conditions did not significantly differ from the $3 predictable amount.