Table 4.

The most important findings in clinical studies on major cannabinoids and their related compounds.

Class	Compounds	Clinical Study	Results	Reference
CBD THC	CBD THC THC + CBD	A 4-way, double-blind, placebo-controlled crossover design study in cannabis users. 48 volunteers, CBD (16 mg), THC (8 mg), THC + CBD (8 mg + 16 mg), and placebo, by inhalation.	CBD improved emotional facial affect recognition at 60% emotional intensity. THC was detrimental to the recognition of ambiguous faces of 40% intensity. THC alone and combined THC+CBD equally increased feelings of being “stoned”.	[145]
CBD	CBD	Double-blind, placebo-controlled trial. 120 children and young adults with the Dravet syndrome and drug-resistant seizures, CBD oral solution, 20 mg/kg of body weight/day or placebo, in addition to standard antiepileptic treatment.	The median frequency of convulsive seizures per month decreased from 12.4 to 5.9 with cannabidiol, as compared with a decrease from 14.9 to 14.1 with placebo. The percentage of patients who had at least a 50% reduction in convulsive seizure frequency was 43% with cannabidiol and 27% with placebo.	[160]
	CBD	Double-blind, randomized clinical trial in 199 children with Dravet syndrome on cannabidiol (10 or 20 mg/kg/d) or matched placebo for 14 weeks.	Convulsive seizure frequency compared with baseline was reduced by 48.7% in the 10 mg/kg/d cannabidiol group and 45.7% in the 20 mg/kg/d cannabidiol group vs. 26.9% in the placebo group.	[161]
	CBD	Double-blind, placebo-controlled trial conducted at 30 clinical centers; we randomly assigned patients with Lennox–Gastaut syndrome. 225 patients were enrolled; 76 patients were assigned to the 20 mg cannabidiol group, 73 to the 10 mg cannabidiol group, and 76 to the placebo group.	The median percent reduction from baseline in drop seizure frequency during the treatment period was 41.9% in the 20 mg cannabidiol group, 37.2% in the 10 mg cannabidiol group, and 17.2% in the placebo group.	[162]
	CBD	Double-blind, placebo-controlled, randomized crossover trial in 39 healthy young subjects. A single dose of cannabidiol e-liquid (0.25 mL, 5% cannabidiol, 12.5 mg cannabidiol) and once placebo for vaping after learning 15 unrelated nouns.	Cannabidiol enhanced verbal episodic memory performance (placebo: 7.03 [2.34]; cannabidiol 7.71 [2.48]).	[163]
	CBDV	Case–control, placebo-controlled, randomized, double-blind, repeated-measures, crossover study on 34 subjects with autism spectrum disorder.	CBDV shifts subcortical levels of the brain’s primary excitatory metabolite glutamate both in the neurotypical and autistic brain; however, there may be significant response variability in ASD.	[142]