Reduction of delta 9-THC provoked anxiety | Double-blinded, placebo-controlled clinical trial | Sample: 8 healthy volunteers (six men and two women), aged between 20 and 38 years (average 27) | Each volunteer participated in five experimental sessions, separated by a minimum interval of 1 week. Volunteers received orally one of the following treatments: Delta-9-THC 0.5 mg/kg, 1 mg/kg CBD, a mixture containing 0.5 mg/kg delta 9-THC and 1 mg/kg CBD; 10 mg placebo; 10 mg diazepam as control group | Interviews and spontaneous reports, Spielberger’s state- trait anxiety inventory (STAI), Addiction Research Center Inventory for Marihuana Effects (ARCI-Mu), Analogue Self-Rating Scale for Subjective Feelings; Scale of Bodily Symptoms Radial Artery Pulse Rate was used to assess subject’s anxiety state | CBD treatment blocked the anxiety provoked by delta 9-THC This antagonism does not appear to be caused by a general block of delta 9-THC effects since no change was detected in the pulse-rate measurements | Action of cannabidiol on the anxiety and other effects produced by delta 9-THC in normal subjects; Zuardi et al. [23] |
Modulation of delta 9-THC effects | Randomized, double-blind, placebo-controlled clinical trial | Sample: 40 healthy male volunteers aged between 21 and 34 years | 8 groups of 5 volunteers each received, respectively, placebo, 30 mg of delta 9-THC, 15, 30, and 60 mg of CBD, and mixtures of 30 mg of delta-9-THC plus either 15, 30, or 60 mg of CBD | Pulse rate, time production tasks and psychological logical reactions were measured at several time intervals after drug ingestion | The dose of 15–60 mg of CBD alone provoked no effects CBD blocked most of the effects of delta 9-THC when both drugs were given together CBD also decreased the anxiety component of Ag-THC effects | Cannabidiol modulates the effects of a 9-tetrahydrocannabinol in man [39] |