Review of: de Meneses-Gaya C et al, Braz J Psychiatry 2020 (Epub ahead of print)

Cocaine use disorder is notoriously difficult to treat, with no approved pharmacological treatments. Brazil, where this study was done, is said to have one of the highest cocaine consumption rates in the world (Abdalla RR et al, Addict Behav 2014;39(1):297–301), and use of crack-cocaine is disproportionately common, with a one-year prevalence of 2% compared to 0.3% in the US (www.tinyurl.com/asy9ajtj). Prior studies have suggested that cannabinoids may help reduce cocaine craving and consumption, but none of these studies tested pure cannabidiol (CBD) or specifically examined people who use crack-cocaine. The authors designed a randomized, double-blind, placebo-controlled trial of cannabidiol to treat acute craving, anxiety, and depression during withdrawal from crack-cocaine.

The subjects were 31 adult male inpatients with DSM-IV diagnoses of crack-cocaine dependence who were admitted to a psychiatric hospital. Most used at least 5 times a week, and the mean duration of use was 12 years. The subjects were randomly assigned to a treatment group that received 150 mg of CBD twice daily for 10 days, or a control group that received placebo.

Each day, researchers tried to induce cocaine craving by showing participants brief films filled with crack-related content. The level of craving was assessed before and after each showing, using validated scales. Symptoms such as depression, anxiety, and insomnia were assessed as well using the Beck Depression Inventory and Beck Anxiety Inventory.

The completion rate was high: 79% in the treatment group and 82% in the control group. Both groups showed significant improvement over the course of the trial in intensity of craving and saw improvements in anxiety and depression; however, there were no differences on any measure between the active and control groups.

Limitations of the study include the small number of participants, the short trial period, and the relatively low dose of CBD. Importantly, the inpatient setting with its enforced abstinence may have washed out any additional effects of CBD.

CATR’s Take
CBD was no more helpful than placebo for diminishing cocaine cravings in this admittedly small and rather limited research trial, despite promising results from preclinical studies. Hopefully, larger and more flexibly dosed studies will provide more definitive data in the future.