Pharmacological treatment of cannabis dependence

Cannabis is the most frequently used illegal psychoactive substance in the world. There is a significant increase in the number of treatment admissions for cannabis use disorders in the past few years, and the majority of cannabis-dependent individuals who enter treatment have difficulty in achieving and maintaining abstinence. Thus, there is increased need for medications that can be used to treat this population. So far, no medication has been shown broadly and consistently effective; none has been approved by any national regulatory authority. Medications studied have included those that alleviate symptoms of cannabis withdrawal (e.g., dysphoric mood, irritability), those that directly affect endogenous cannabinoid receptor function, and those that have shown efficacy in treatment of other drugs of abuse or psychiatric conditions. Buspirone is the only medication to date that has shown efficacy for cannabis dependence in a controlled clinical trial. Results from controlled human laboratory studies and small open-label clinical trials suggest that dronabinol, the COMT inhibitor entacapone, and lithium may warrant further study. Recent pre-clinical studies suggest the potential of fatty acid amide hydrolase (FAAH) inhibitors such as URB597, endocannabinoid-metabolizing enzymes, and nicotinic alpha7 receptor antagonists such as methyllycaconitine (MLA). Controlled clinical trials are needed to evaluate the clinical efficacy of these medications and to validate the laboratory models being used to study candidate medications.