Psychopharmacology
May 1, 2019
Thomas R. Arkell, Nicholas Lintzeris, Richard C. Kevin et al.
177 citations
Both THC-dominant and THC/CBD equivalent cannabis increased lane weaving during simulated driving but had little effect on other driving measures. Impairment on the Digit Symbol Substitution Task, Divided Attention Task, and Paced Auditory Serial Addition Task occurred with both active cannabis types, with worse performance on the latter two tasks after THC/CBD equivalent cannabis. Subjective feelings of being "stoned" and confidence in driving ability did not differ by CBD content. Peak plasma THC concentrations were higher after THC/CBD equivalent cannabis, suggesting a possible pharmacokinetic interaction. Cannabis with equivalent CBD and THC appears no less impairing than THC-dominant cannabis, and CBD may exacerbate THC-induced impairment in some circumstances.
Addiction Biology
December 22, 2021
Thomas R. Arkell, Richard C. Kevin, Frederick Vinckenbosch et al.
45 citations
Males and females show few differences in their acute responses to a moderate dose of vaporized cannabis containing 13.75 mg THC, with or without 13.75 mg CBD. After controlling for body mass index and plasma THC concentrations, males performed better on a divided attention task and had higher peak plasma levels of a THC metabolite (11-COOH-THC), but no sex differences appeared in subjective drug effects, cardiovascular measures, or plasma concentrations of THC, CBD, or other metabolites. The findings suggest an absence of systematic sex differences at this dose, though differences might emerge with higher THC doses or other routes of administration.
Psychopharmacology
October 13, 2022
Nadia R. P. W. Hutten, Thomas R. Arkell, Frederick Vinckenbosch et al.
36 citations
Vaporized cannabis containing both THC and cannabidiol (CBD) produces less anxiety than THC alone, but this effect depends on a person's baseline anxiety level. In a placebo-controlled trial with 26 healthy recreational cannabis users, THC-dominant cannabis (13.75 mg THC) and THC/CBD-equivalent cannabis (13.75 mg each) both increased self-rated state anxiety compared to placebo, though the combination caused significantly less anxiety than THC alone. When baseline anxiety was low, CBD completely counteracted THC-induced anxiety; when baseline anxiety was high, CBD did not counteract it. Trait anxiety did not influence the results, and objective measures of attention bias showed no effects.