Effectiveness of Contingency Management in the Treatment of Stimulant Use Disorders

Background and Purpose: Stimulant use disorders (StUDs) are linked to various medical complications, including cardiovascular, neurological, pulmonary issues and susceptibility to infectious diseases (Substance Abuse and Mental Health Services Administration [SAMHSA], 2021). In addition, overdose deaths from stimulants have increased dramatically over the years (Ahmad et al., 2024). Various psychosocial treatment modalities have been utilized to support individuals with StUDs, with contingency management (CM) rising as one of the most prominent approaches. CM is a behavior therapy approach grounded in operant conditioning principles, with the goal of altering behavior through positive reinforcement techniques. In this approach, clients are rewarded upon achieving their treatment goals such as abstaining from substance use. A systematic literature review was conducted to assess the effectiveness of CM in the treatment of StUDs. The primary objective of this review was to evaluate the evidence for substance use outcomes, treatment retention outcomes, and other key morbidity and mortality outcomes associated with using CM for treating stimulant use disorders to assess its strength as an evidence-based practice. Such practices have been emphasized for use in social work interventions.

Methods: Research databases were searched using “(Contingency Management AND (cocaine OR methamphetamine OR amphetamine OR stimulant*)” keyword phrases. Studies were included in full review if they were experimental in design, used primary data, primarily involved participants with stimulant use disorders, and focused on drug use and/or mortality outcomes. Studies focusing on participants with other substance use disorders, or those involving methadone or buprenorphine maintenance clients were excluded. Two reviewers independently screened articles and resolved any discrepancies collaboratively.

Results: Thirty-six studies were eligible for review. Twenty-four studies examined voucher-based CM, ten examined prize-based CM, and two examined abstinence-based housing CM. All of them examined drug use outcomes and thirty-three studies examined retention. Three studies examined morbidity outcomes (e.g., HIV-risk), whereas none of them focused on mortality. Eighteen had follow-up data. Twenty-six studies primarily incentivized abstinence from stimulants; whereas nine incentivized abstinence from the other drugs and/or alcohol in addition to stimulants. One study incentivized treatment attendance only. The majority of the studies found that CM was effective in promoting abstinence, increasing retention in treatment, and reducing risk for HIV. Several studies with follow-up assessment found that the benefits of CM on reducing substance use persisted beyond the treatment duration.

Conclusions and Implications: This review highlights the effectiveness of CM for individuals with stimulant use disorders. The question of how many substances to target for reinforcement incentives remains unanswered, as results did not vary based on the number of substances targeted. Despite the evidence supporting CM, it has not been widely implemented, mainly due to insufficient funding and reluctance towards CM. Further exploration of CM's cost-effectiveness is recommended, as earnings per participant varied based on CM type and reinforced behavior. Long-term longitudinal studies are needed to investigate the potential impact of contingency management on morbidity and mortality outcomes. Given the demonstrated effectiveness of CM in treating StUDs and other SUDs, social workers can benefit from training on the CM model.