Effects of cannabidiol on risky decision-making and autonomic function in alcohol use disorder

AIMS: To examine the effects of cannabidiol (CBD) on psychophysiological responding and risky decision-making in individuals with alcohol use disorder (AUD). METHODS: In a double-blind, placebo-controlled crossover trial, 18 participants with AUD completed the Columbia Card Task (CCT) following administration of CBD and placebo. Skin conductance responses (SCR) and high-frequency heart rate variability (HF-HRV) were assessed as indices of autonomic responding during task performance. Risk-taking was indexed by the number of cards selected on the CCT. RESULTS: CBD did not significantly affect SCR (P = .16, pBH = .326) or risky decision-making on the CCT (P > .63, pBH = 0.67). However, CBD significantly increased HF-HRV (β = 0.53, SE = 0.19, P = .005; pBH = 0.020). There was no evidence that the relationships between HF-HRV or SCR and risky decision-making differed between CBD and placebo conditions (drug × HF-HRV: P = .92; drug × SCR: P = .958; both pBH = .958). DISCUSSION: CBD increased HF-HRV but did not significantly alter SCR, risky decision-making, or the relationship between autonomic responses and risky decision-making. These findings suggest that CBD influences autonomic responding during task performance, although the functional significance of this effect remains uncertain. The modest sample size and relatively healthy, non-treatment-seeking sample may have limited the ability to detect broader physiological and behavioural effects.