Addiction
February 8, 2023
Will Lawn, Katie Trinci, Claire Mokrysz et al.
36 citations
Adolescent cannabis users are neither more resilient nor more vulnerable than adult cannabis users to the acute psychotomimetic, verbal memory-impairing, or subjective effects of cannabis. In a randomized, double-blind, placebo-controlled crossover experiment with 24 adolescents (16-17 years old) and 24 adults (26-29 years old) who used cannabis 0.5-3 days per week, vaporized THC (8 mg for a 75 kg person) and THC plus CBD (24 mg) both significantly increased subjective drug effect, impaired verbal episodic memory, and increased psychotomimetic effects compared to placebo. There was no evidence that adolescents differed from adults in their responses, and CBD did not modulate the acute effects of THC.
Journal of Psychopharmacology
July 29, 2023
Natalie Ertl, Will Lawn, Claire Mokrysz et al.
17 citations
Regular cannabis use is associated with localized increases in connectivity of the executive control network (ECN), which may reflect adaptive or compensatory changes in response to regular intoxication. Adolescents generally showed weaker connectivity than adults across multiple brain networks, consistent with normal developmental effects. However, there were no significant interactions between age group and cannabis user group, meaning the connectivity changes linked to cannabis use did not differ between adolescents and adults. No associations were found between cannabis use frequency and any connectivity measures.
Psychopharmacology
February 28, 2024
Daniel L. Hall, Will Lawn, Shelan Ofori et al.
5 citations
Acute intoxication with vaporized THC eliminated attentional bias away from cannabis-related cues in both adolescents and adults who used cannabis 0.5–3 days per week. In a randomized, double-blind, placebo-controlled crossover study with 48 participants (24 adolescents aged 16–17 and 24 adults aged 26–29), a weight-adjusted dose of 8 mg THC eliminated the bias, while adding 24 mg CBD did not alter this effect. There was no significant difference in response between age groups. The findings suggest that acute THC intoxication shifts attentional processing of cannabis cues, but CBD does not moderate this effect.
The International Journal of Neuropsychopharmacology
February 1, 2025
Martine Skumlien, Tom P. Freeman, Daniel L. Hall et al.
In weekly cannabis users, cannabis suppresses the brain's anticipatory reward response to money, and cannabidiol (CBD) does not moderate this effect. The adolescent reward circuitry is not differentially sensitive to the acute effects of cannabis on reward anticipation. This double-blind, placebo-controlled, crossover study with 23 adults (26-29 years) and 24 adolescents (16-17 years) used functional magnetic resonance imaging (fMRI) to measure brain activity during a monetary reward anticipation task after inhaling cannabis with tetrahydrocannabinol (THC), THC plus CBD, or placebo. THC acutely reduced reward anticipation activity in the ventral striatum and right insula compared with placebo. THC plus CBD also reduced activity in these regions. The effects were the same in adolescents and adults.