Pharmacological Treatment of Cannabis-Related Disorders: A Narrative Review

Background: Cannabis is the most widely used illicit psychoactive substance world-wide, yet no medication is approved for the treatment of intoxication, withdrawal, or cannabis use disorder (CUD). Objective: To comprehensively review the current state of knowledge. Method: Search of the PubMed electronic data base and review of reference lists of relevant articles to identify controlled clinical trials of pharmacological treatment. Results: The search identified 4 trials for specific intoxication symptoms (none for global intoxication), 7 trials for withdrawal, and 12 phase II trials for CUD. One or two trials each suggest that propranolol is effective for some intoxication symptoms, antipsychotics for cannabis-induced psychosis, and dronabinol (synthetic THC) and gabapentin for cannabis withdrawal. Of 10 medications and one medication combination studied in 12 trials for CUD, only two medications were effective (in single trials): gabapentin and N-acetylcysteine (in adolescents). Not effective were dronabinol and several antidepressants, anticonvulsants, and antianxiety medications. Three trials of antidepressants for CUD with comorbid depression gave inconsistent results. A trial of atomoxetine for CUD with comorbid ADHD showed no efficacy. Five trials of second-generation antipsychotics for CUD with comorbid schizophrenia showed none better than any other. Conclusion: Further research is needed to confirm the efficacy of gabapentin for withdrawal and gabapentin and N-acetylcysteine for CUD and to develop new medications for all 3 cannabis-related disorders.