Psilocybin-assisted psychotherapy vs. placebo in treatment of alcohol disorder
The comparison condition was psilocybin or diphenhydramine (Benadryl), and both groups got addiction counseling.>Participants correctly guessed their treatment assignment in 93.6% of the first sessions, reporting a mean (SD) certainty of 88.5% (23.2%). In the second session, 94.7% guessed correctly, and mean (SD) certainty was 90.6% (21.5%). Study therapists correctly guessed treatment 92.4% of the time for first sessions and 97.4% for second sessions, and their mean (SD) certainties were 92.8% (16.3%) and 95.4% (2.9%), respectively.This is not a criticism, as these trials are very hard to blind, but as you can see in hindsight they could as well have not bothered with blinding at all. So we need to interpret this as a randomized but unblinded trial.The researchers are well aware of this, and I suspect it will inform the next steps of their research.>Several limitations of the study warrant discussion. First, diphenhydramine was ineffective in maintaining the blind after drug administration, so biased expectancies could have influenced results. Control medications such as methylphenidate,42 niacin,2 and low-dose psilocybin1 likewise did not adequately maintain blinding in past psilocybin trials, so this issue remains a challenge for clinical research on psychedelics.