Contingency Management Incentives for Sobriety

Alcohol Research & Health, Spring, 1999 by Stephen T. Higgins, Nancy M. Petry

Contingency management (CM), the systematic reinforcement of desired behaviors and the withholding of reinforcement or punishment of undesired behaviors, is an effective strategy in the treatment of alcohol and other drug (AOD) use disorders. Animal research provides the conceptual basis for using CM in AOD abuse treatment, and human studies have demonstrated the effectiveness of CM interventions in reducing AOD use; improving treatment attendance; and reinforcing other treatment goals, such as complying with a medication regimen or obtaining employment. KEY WORDS: addiction care; treatment method; intervention; reinforcement; treatment outcome; AOD (alcohol and other drug) abstinence; problematic AOD use; multiple drug use; AOD dependence; treatment goals; treatment research; patient compliance; employment; animal model; literature review

Contingency management (CM) [1] is a strategy used in alcohol and other drug (AOD) abuse treatment to encourage positive behavior change (e.g., abstinence) in patients by providing reinforcing consequences when patients meet treatment goals and by withholding those consequences or providing punitive measures when patients engage in the undesired behavior (e.g., drinking). For example, positive consequences for abstinence may include receipt of vouchers that are exchangeable for retail goods, whereas negative consequences for drinking may include withholding of vouchers or an unfavorable report to a parole officer. The reinforcing or punishing consequences may be contingent on objective evidence of recent AOD use or on another behavior important in the treatment process, such as compliance with a medication regimen or regular clinic attendance. Often, clinicians implement CM procedures through written contracts that derail the desired behavior change, duration of intervention, frequency of monitoring, and pot ential consequences of the patient's success or failure in making the agreed-upon behavior changes.

An extensive body of research supports CM'S efficacy in treating various behavioral disorders, including AOD abuse (Higgins and Silverman 1999; Higgins et al. 1998). This article briefly reviews the conceptual background and empirical research demonstrating the efficacy of CM in AOD abuse treatment.

CONCEPTUAL AND BASIC SCIENCE FOUNDATIONS

The use of reinforcing and punishing consequences to alter the form and frequency of voluntary behavior is known as operant conditioning, a method that provides the conceptual framework for CM. Within the CM framework, AOD use is considered a form of operant behavior--that is, behavior that is maintained in part by the reinforcing biochemical effects of the abused substance and by reinforcing environmental influences (e.g., social reinforcement from peers).

Findings from animal research support the use of CM in the treatment of AOD use disorders. Such research demonstrates, for instance, that animals exhibit consumption patterns indicative of dependence and that researchers can modify animals' AOD intake by using reinforcing and punishing consequences. Generally, laboratory animals voluntarily ingest the same substances that humans abuse (Griffiths et al. 1980). Rats and monkeys, for example, will voluntarily consume large quantities of cocaine, opioids, and alcohol. Neither a prior history of drug exposure nor physical dependence is necessary to support ongoing and stable patterns of AOD use in laboratory animals. Moreover, studies of voluntary AOD consumption by laboratory animals show that once a pattern of heavy consumption has been established, animals will complete cumbersome tasks (e.g., press a lever numerous times) to obtain and consume the desired substance. Additionally, laboratory animals will forgo other reinforcers, including sweet liquids, high-c alorie solutions, and in some cases even basic sustenance, to engage in AOD use (Petry and Heyman 1995). These behavioral patterns are analogous to those exhibited by AOD-dependent humans, who often spend significant amounts of time and money abusing alcohol and recovering from AOD use, and who often give up recreation, employment, and family activities to do so.

These findings--that laboratory animals voluntarily consume many of the same substances that humans abuse and exhibit consumption patterns indicative of dependence--suggest that the necessary neurobiological systems to experience AOD-induced reinforcement and to engage in compulsive AOD use are widely represented across different species. However, laboratory studies also indicate that individual and environmental factors clearly influence susceptibility to AOD use and abuse (Wolffgramm and Heyne 1995). For example, when first exposed to alcohol, rats bred for high alcohol intake will voluntarily consume larger amounts of alcohol than non-selectively bred rats. However, even initially low-alcohol-consuming rats will voluntarily consume large quantities of alcohol under certain conditions. For example, stress, social isolation, and reduced access to food, liquid, or opportunities for exercise all promote AOD use in laboratory animals. Therefore, susceptibility to the reinforcing effects of AODs appears to be a product of normal neurobiological systems common to many species that can be heightened by certain individual and environmental factors.