Animal studies have shown sex differences in cannabis-induced analgesia, but these studies had not previously been done in humans. A new study explored this issue by assessing the analgesic and subjective effects of cannabis in 42 users, half of whom were male and the other half female. Participants were given cannabis containing either 0 or up to 5.6 percent THC, the psychoactive ingredient in marijuana. Pain levels were then assessed in the cold-pressor test, where participants submerge their hands in cold water and researchers record the time it takes for participants to report pain and to remove the hand. Participants also answered questions designed to assess the subjective effects of cannabis.
Active cannabis increased pain tolerance in both men and women for a short time after smoking, and reduced pain sensitivity in men, but not women. In contrast, active cannabis increased ratings for both sexes in subjective measures of abuse liability (e.g., liking the drug), drug strength, and intoxication ("high"). This suggests that sex-dependent differences should be considered when considering cannabis as a potential therapeutic for pain.
- Cooper, ZD and Haney, M. Sex-dependent effects of cannabis-induced analgesia. Drug and Alcohol Dependence. doi: 10.1016/j.drugalcdep.2016.08.001.