New research sheds light on the pharmacodynamic effects of cannabis-infused food. The findings, which appear in Drug and Alcohol Dependence, indicate that relatively small differences in doses can result in large differences in effects among infrequent cannabis users.
“There have been very few controlled studies done in which cannabis edibles were administered, and most did not explore multiple doses,” said study author Ryan Vandrey, an associate professor of psychiatry and behavioral sciences at Johns Hopkins University.
“Thus, we felt this was an important study to determine the effects of a range of doses in healthy adults to ascertain the safety of edible cannabis products available in retail stores in many places. Another important component of this study was to determine the effect of these single acute doses on drug-testing outcomes.”
In the double-blind study, 17 seventeen healthy adults who had not used cannabis for at least 60 days participated in four experimental sessions scheduled a minimum of one week apart. During each session, they consumed a cannabis-infused brownie that contained either 0, 10, 25, or 50 mg of THC — and then completed various physiological and psychological assessments over the course of the next 9 hours.
The 10 mg dose was not associated with any cognitive impairments. But the 25 and 50 mg doses produced moderate to severe impairments in attention, psychomotor performance, and working memory.
“The effects of ingesting THC-containing food products can vary greatly based on relatively small differences in total dose. Most participants tolerated the 10 mg THC dose well, but many participants reported adverse effects and exhibited impairment on cognitive tests after doses of 25 mg or 50 mg THC,” Vandrey told PsyPost.
“Drug effects occurred much later and lasted longer compared with when cannabis is smoked. Peak drug effects were observed from 1.5 to 3 hours after dosing and lasted 5-8 hours. Also, though the 25 mg and 50 mg doses produced robust impairment, blood THC testing indicated that our participants were below the threshold cut-off commonly used by law enforcement to identify individuals driving under the influence of cannabis.”
The study — like all research — includes some limitations.
“There is so much more research to be done in this area. We need studies of additional doses, cannabis infused into other types of food and beverage formulations, cannabis that varies systematically with respect to chemical composition (e.g. amount of THC, CBD, and other chemical contents of the cannabis plant), repeat dosing studies, and studies with different participant demographics,” Vandrey said.
The study, “Pharmacodynamic dose effects of oral cannabis ingestion in healthy adults who infrequently use cannabis“, was authored by Nicolas J. Schlienz, Tory R. Spindle, Edward J. Cone, Evan S. Herrmann, George E. Bigelow, John M. Mitchell, Ronald Flegel, Charles LoDico, and Ryan Vandrey.
(Image by Eugenio Cuppone from Pixabay)