Research
High-Dose THC Can Produce Psychedelic-Like States, Johns Hopkins Study Finds
A pilot study suggests oral THC may be mistaken for psilocybin under clinical trial conditions, offering a potential active comparator for psychedelic research.
Researchers at Johns Hopkins University School of Medicine found that high oral doses of THC can produce subjective effects similar to psilocybin, with some participants unable to distinguish between the two substances. The findings could help address unblinding in psychedelic clinical trials by using THC as an active control.
High doses of THC from cannabis may produce psychoactive effects that are difficult to distinguish from those caused by the psychedelic psilocybin, according to a new study from the Johns Hopkins University School of Medicine.
The pilot investigation involved four adults who underwent three or four sessions during which they received either 25 milligrams of psilocybin, 25 milligrams of THC, 50 milligrams of THC, or a placebo. The THC was administered either as synthetic dronabinol or as a whole-plant cannabis distillate extract.
Both participants and session facilitators were blinded to what was actually received at the time and were asked to guess afterwards. Every participant correctly identified when they had received a placebo or the real psychedelic, but the 25 mg dronabinol condition was rated as more similar to a classic psychedelic or dissociative than a cannabinoid.
The whole-plant cannabis distillate extract of THC was rated by participants as having a stronger overall subjective drug effect than equivalent doses of synthetic dronabinol. The paper, published in the journal Psychopharmacology, stated that 25 mg of THC in both forms yielded a subjective experience similar to 25 mg psilocybin.
Researchers said the results could have implications for future clinical trials of psychedelics by helping to address the problem of unblinding, where participants are able to tell whether they have received the drug being tested, a placebo, or a comparator substance. An appropriate dose of THC may provide an adequate active comparator condition for ongoing psychedelic clinical trials, they suggested.
The study was designed to mimic the set and setting in which psychedelic research is typically carried out. Participants laid on a couch, wore eye shades, listened to music, and were told to turn inward and be present for whatever arises within consciousness.
The study was funded by the Wana Brand Foundation, which was launched by the CEO of the cannabis company Wana Brands.