Absence of Evidence for Sustained Effects of Daily Cannabidiol Administration on Anandamide Plasma Concentration in Individuals with Cocaine Use Disorder: Exploratory Findings from a Randomized Controlled Trial

Background: Cannabidiol (CBD) has been proposed to have a therapeutic potential over a wide range of neuropsychiatric disorders, including substance use disorders. Pre-clinical evidence suggests that CBD can increase anandamide (AEA) plasma concentration, possibly mediating some of its therapeutic properties. Whether CBD exerts such an effect on AEA in individuals with cocaine use disorder (CUD) remains unknown.Aims: To explore the sustained effects of daily CBD administration on AEA plasma concentrations compared with placebo in CUD.Methods: We used data from a randomized, double-blind, placebo-controlled trial evaluating CBD's efficacy in CUD. Seventy-eight individuals were randomized to receive a daily oral dose of 800 mg CBD (n = 40) or a placebo (n = 38). Participants stayed in an inpatient detoxification setting for 10 days, after which they were followed in an outpatient setting for 12 weeks. AEA plasma concentration was measured at baseline and at 23-h post CBD ingestion on day 8 and week 4. A generalized estimating equation model was used to assess CBD's effects on AEA, and sensitivity analyses were computed using Bayesian linear regressions.Results: Sixty-four participants were included in the analysis. Similar mean AEA plasma concentrations in both treatment groups (p = 0.357) were observed. At day 8, mean AEA plasma concentrations (+/- standard deviation) were 0.26 (+/- 0.07) ng/mL in the CBD group and 0.29 (+/- 0.08) ng/mL in the placebo group (p = 0.832; Bayes factor [BF] = 0.190). At week 4, they were 0.27 (+/- 0.09) ng/mL in the CBD group and 0.30 (+/- 0.09) ng/mL in the placebo group (p = 0.181; BF = 0.194).Conclusion: While not excluding any potential acute and short-term effect, daily CBD administration did not exert a sustained impact on AEA plasma concentrations in individuals with CUD compared with placebo.Registration: clinicaltrials.gov (NCT02559167).