THC produces psychotomimetic effects, but when CBD is coadministered with THC, those effects are reduced. In a double-blind, placebo-controlled crossover trial with 18 cannabis social club members, participants given THC plus CBD reported lower psychotomimetic scores than those given THC alone. CBD alone and placebo showed no psychotomimetic effects. The findings support CBD's antipsychotomimetic properties in real-world settings and link the endocannabinoid system to psychotic-like symptoms, with implications for medical cannabis practice and schizophrenia.
Chronic cannabis users who consumed an extract containing only THC showed lower cognitive empathy than those who consumed only CBD. Participants who consumed only CBD showed higher cognitive theory of mind (the ability to infer others' mental states) compared with placebo. No differences were found on emotional measures of empathy or theory of mind. The study provides evidence that CBD can improve theory-of-mind abilities in chronic cannabis users, suggesting a role for the endocannabinoid system in social cognition and potential relevance for neuropsychiatric disorders such as schizophrenia and autism.