Carbidopa/Levodopa Combined With Behavioral Therapy for the Treatment of Cocaine Dependence

Cocaine dependence is a major public health problem and the development of a treatment for this disorder is a priority. To date, treatment interventions based on positive incentive principles have shown the strongest effects for improving substance use outcomes. One such example is contingency management (CM) interventions in which nondrug rewards are used to compete with cocaine. Recent evidence suggests that certain medications improve response to CM interventions, particularly agents that target dopamine reward systems in the brain. A promising dopamine-enhancing medication is levodopa. The study team has observed the strongest effects of levodopa when the medication is administered in the context of CM therapy, perhaps through mechanisms that enhance reward saliency. The proposed study is designed to further evaluate this promising treatment approach. Cocaine dependent outpatients will participate in a randomized, 2-group (levodopa vs. placebo), double-blind clinical trial. CM will be behavioral therapy platform for both treatment groups. The study will test the primary hypothesis that CM+levodopa will be more effective than CM+placebo in reducing cocaine use. This study is expected to validate the usefulness of a new behavioral-pharmacological treatment approach for cocaine dependence.