Cannabidiol (CBD) content in vaporized cannabis does not prevent tetrahydrocannabinol (THC)-induced impairment of driving and cognition
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.