Cannabis, especially high-THC varieties, may be able to produce perceptual changes, aversiveness, and mystical experiences similar to those caused by classic psychedelics like psilocybin. Although cannabis is not typically regarded as having psychedelic effects in modern research, historical use alongside psychedelics suggests otherwise. The review finds that recent controlled studies may have failed to observe these effects due to the doses, set, and settings used. Further research is needed to test high doses of THC in therapeutic contexts similar to those used for psychedelics. If cannabis can reliably generate psychedelic experiences, it could be explored as an adjunctive treatment for psychiatric disorders and as an active comparator in clinical trials.
Combining cannabis edibles with alcohol worsens driving impairment more than either substance alone. In a controlled experiment with 25 healthy adults who reported prior co-use, driving performance was significantly impaired under most active drug conditions, including 25 mg THC with alcohol at 0.05% breath alcohol concentration. The legal alcohol intoxication limit of 0.08% may be too high when cannabis has also been consumed. Standard field sobriety tests often failed to detect impairment that was evident in driving measures. The findings suggest a need for better impairment detection and policies that account for co-use.