INTRODUCTION
verbal episodic memory, tachycardia, verbal episodic memory impairment, memory impairment, attention deficits
DRUG EFFECT
Cannabis is the most commonly used internationally controlled drug in the world and is particularly popular among adolescents. Between 15% and 20% of English 15‐year‐olds [Adolescence is a period during which important biological, neural, psychological, social and personal changes occur [Acutely, cannabis reliably produces an array of transient and dose‐dependent effects including intoxication, euphoria, memory impairment, psychotomimetic effects, anxiogenic effects, attention deficits and tachycardia [Despite the pervasiveness of adolescent cannabis use, only one controlled human experiment has compared the acute effects of cannabis in adolescents under the age of 18 years and adults [More recently, one placebo‐controlled study compared the impact of oral THC (7.5 and 15 mg) in young people 18–20 years old and adults 30–40 years old with limited cannabis experience [In sum, no studies have investigated the combined effects of CBD and THC in adolescents, in whom the impact may be different from adults. Only one controlled experiment to date has compared the acute effects of cannabis in human adolescents under the age of 18 years with adults [To address these limitations, we tested equal numbers of female and male participants, included a combined THC and CBD (‘THC + CBD’) condition as well as THC‐only (‘THC’) and placebo (‘PLA’) conditions, carefully matched cannabis use frequency between the groups and collected pharmacokinetic data. In the largest study of its kind, we aimed to replicate the adolescent versus adult difference in acute effects of cannabis and to explore the modulatory impact of CBD co‐administration in these age groups.First, we hypothesised that, across age‐group, there would be a main effect of drug, such that (i) subjective ‘feel drug effect’, (ii) verbal episodic memory impairment, and (iii) psychotomimetic effects, would be greater on ‘THC’ and ‘THC + CBD’ than placebo. Second, we hypothesised that CBD in ‘THC + CBD’ would reduce the (i) verbal episodic memory impairing, and (ii) psychotomimetic effects, relative to ‘THC’, but (iii) subjective ‘feel drug effect’ would be similar on ‘THC’ and ‘THC + CBD’. Third, we hypothesised there would be an interaction between age‐group and drug, such that the expected difference between the ‘THC’ and ‘PLA’ conditions on measures (i)–(iii) would be greater for adults than for adolescents.