Sex differences in the acute effects of intravenous (IV) delta-9 tetrahydrocannabinol (THC).

Background: Cannabis is the most common illicit drug used in the USA and its use has been rising over the past decade, while the historical gap in rates of use between men and women has been decreasing. Sex differences in the effects of cannabinoids have been reported in animal models, but human studies are sparse and inconsistent. We investigated the sex differences in the acute subjective, psychotomimetic, cognitive, and physiological effects of intravenous (IV) delta-9 tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis. Methods: Healthy male and female individuals, with limited exposure to cannabis, participated in a double blind, placebo-controlled study of intravenous (IV) placebo or THC at two doses (0.015 mg/kg and 0.03 mg/kg). Visual analog scale (VAS) was used to measure subjective effects, Psychotomimetic States Inventory (PSI) and the Clinician-Administered Dissociative Symptoms Scale (CADSS) were used to assess the psychotomimetic effects and perceptual alterations, respectively, and Rey Auditory Verbal Learning Task (RAVLT) was used to evaluate cognitive effects. Outcome variables were represented as the peak change from baseline for each variable, except RAVLT which was used only once per the test day after the subjective effects. Results: A total of 42 individuals participated in this study. There were no significant differences between male and female participants in background characteristics. There was a significant main effect of sex on the VAS scores for THC-induced "High" (F_1,38 = 4.27, p < 0.05) and a significant dose × sex interaction (F_2,77 = 3.38, p < 0.05) with female participants having greater "High" scores than male participants at the lower THC dose (0.015 mg/kg). No other sex differences were observed in acute subjective, psychotomimetic, cognitive, or physiological effects of THC. Conclusion: There were significant sex differences in subjective effects of feeling "High" at a lower dose of THC. However, there were no other sex-related differences in the subjective, physiological, or cognitive effects of THC. [ABSTRACT FROM AUTHOR]