5. CLINICAL APPLICATIONS OF PSYCHEDELICS FOR OPIOID USE DISORDER: CURRENT KNOWLEDGE
Most research on classic psychedelics’ therapeutic effects on OUD has focused on opioid withdrawal. Other benefits like reduced opioid use from pain relief are less studied. Although these psychedelics are seen as having low abuse potential, their addiction risk in this group awaits thorough evaluation.
5.1. LSD
There are two studies from the early phase of psychedelic research that investigate the use of LSD in people with OUD. The first study, conducted in 1965, was an open-label controlled trial that included 70 patients with OUD, who had recently been hospitalized for treatment of opioid withdrawal.12 The study found that orally administered LSD (at doses of 2ug/kg) was generally well tolerated with no participants requiring medications to counteract adverse effects, with only three participants reporting worsening of psychiatric symptoms. The study did not collect data on traditional OUD outcomes, pain, or functioning. The second study, conducted in 1973, was a randomized controlled trial that included 74 participants with OUD at a residential reentry program.11 Participants were randomized to either a treatment (LSD 300ug-450ug) or control arm. The treatment arm consisted of living in a halfway house from four to six weeks and undergoing 24 hours of preparatory therapy over five weeks and one week of integration therapy post-LSD. At 12 months, 9/36 (25%) of treatment arm participants remained abstinent, compared to 2/37 (5%) of the participants the control group. There were no statistically significant group differences on changes in overall functioning. The authors report that 12 of the 13 of participants who had a “psychedelic peak experience” (using an unnamed questionnaire) appeared more likely to have higher “community adjustment scores” at 12 months. The design of this study makes it difficult to interpret the findings, as there was no control for the impact of the residential treatment component in the treatment arm. There are currently no registered studies planned investigating LSD for OUD or for those on LTOT.