According to the results of a new study, the intensity of ketamine’s psychedelic effects does not predict its effectiveness in treating alcohol use disorder. The research, published in the peer-reviewed journal Addiction, was conducted by researchers from King’s College London and the University of Exeter, and included 96 adult participants aged 18-64 years diagnosed with moderate-to-severe alcohol use disorder (AUD).

Participants who received three weekly ketamine infusions reported strong psychoactive effects, such as altered reality and dissociation, with little sign of tolerance over time. However, the intensity of these experiences did not explain the treatment’s effectiveness. In addition, the level of subjective drug effects did not predict how many days participants remained abstinent over six months.

The findings of this research suggest that ketamine’s therapeutic effects may be driven by mechanisms other than its psychedelic effects. The analysis draws on data from the KARE clinical trial, which evaluated intravenous ketamine-assisted psychotherapy for moderate to severe AUD. Currently, the exact mechanism by which ketamine exerts its benefits remains unknown. “[Our] results challenge the popular theory that the therapeutic benefits of ketamine are driven by its acute psychoactive or mystical-like effects. Instead, our findings suggest other possible reasons why ketamine prevents relapse, such as its ability to alter networks in the brain related to addiction or stimulate new neural connections to form. More research is needed to directly test these hypotheses,” said Dr Will Lawn, the study’s senior author and Senior Lecturer at the Institute of Psychiatry, Psychology & Neuroscience at King’s College London, in a press release.

“We previously showed that ketamine has promise for helping people with alcohol use disorder remain sober and these new findings demonstrate those receiving intravenous ketamine experience the expected subjective effects from the drug, including feelings of altered reality, bodily dissociation and warped time perception, » he added. “However, our results challenge the popular theory that the therapeutic benefits of ketamine are driven by its acute psychoactive or mystical-like effects. Instead, our findings suggest other possible reasons why ketamine prevents relapse, such as its ability to alter networks in the brain related to addiction or stimulate new neural connections to form. More research is needed to directly test these hypotheses.”