“Funding for reinforcers and urine tests can be a barrier to implementation. However, this barrier is likely surmountable as cost-effectiveness studies of contingency management in those with and without serious mental illness support the intervention’s cost-savings,” Michael G. McDonell, Ph.D., of Washington State University and colleagues wrote.
McDonell and colleagues randomized 79 outpatients with serious mental illness and alcohol dependence to one of two treatment arms: one group was assigned to 12 weeks of “contingency management,” where participants were eligible to win prizes for EtG-negative urine samples (defined as < 150 ng/mL) and attendance at treatment sessions; participants in the other group were eligible to receive prizes regardless of EtG results or treatment attendance. Participants in both groups provided urine samples three times per week for 12 weeks.
Each time that participants in the contingency management group tested negative for EtG, they drew tokens from a container representing different magnitudes of reinforcement—50% of the tokens read “good job” (no prize), while the other 50% represented prizes ranging in value from $1 to $80. One additional prize draw was earned for each week of continuous alcohol abstinence, and patients received gift cards for attending all ($10.00) or at least one ($5.00) treatment meeting each week.
Noncontingent participants were eligible for prize draws for each urine sample submitted, regardless of EtG results. They did not need to attend addiction treatment to earn gift cards; instead they received gift cards equal to those earned by the contingency management group during the previous week.
On average the longest duration of alcohol abstinence among individuals randomly assigned to contingency management was more than twice as long as the average longest duration for noncontingent participants, with approximately 1.5 additional weeks of abstinence compared with controls. Contingency management participants were 3.13 times more likely to submit an EtG-negative urine sample during the intervention period compared with controls. They also had significantly fewer days of any drinking and drinking to intoxication throughout the intervention period.
“Results of this study strongly support the efficacy of an EtG-based contingency management intervention for alcohol use disorders,” the researchers wrote. “Group differences in alcohol use observed in this study … suggest that contingency management may be a particularly effective intervention for those with co-occurring serious mental illness and substance use disorders, a high-cost and difficult-to-engage population.”
For related information, see the Psychiatric News article “Researchers Identify Gene Variant Linked With Alcohol Preference.”