“Tripping on Nothing: Placebo Psychedelics and Contextual Factors”, 2020-03-07 (; backlinks; similar):
Rationale: Is it possible to have a psychedelic experience from a placebo alone? Most psychedelic studies find few effects in the placebo control group, yet these effects may have been obscured by the study design, setting, or analysis decisions.
Objective: We examined individual variation in placebo effects in a naturalistic environment resembling a typical psychedelic party.
Method: 33 students completed a single-arm study ostensibly examining how a psychedelic drug affects creativity. The 4-h study took place in a group setting with music, paintings, colored lights, and visual projections. Participants consumed a placebo that we described as a drug resembling psilocybin, which is found in psychedelic mushrooms. To boost expectations, confederates subtly acted out the stated effects of the drug and participants were led to believe that there was no placebo control group. The participants later completed the 5-Dimensional Altered States of Consciousness Rating Scale, which measures changes in conscious experience.
Results: There was considerable individual variation in the placebo effects; many participants reported no changes while others showed effects with magnitudes typically associated with moderate or high doses of psilocybin. In addition, the majority (61%) of participants verbally reported some effect of the drug. Several stated that they saw the paintings on the walls “move” or “reshape” themselves, others felt “heavy…as if gravity [had] a stronger hold”, and one had a “come down” before another “wave” hit her.
Conclusion: Understanding how context and expectations promote psychedelic-like effects, even without the drug, will help researchers to isolate drug effects and clinicians to maximise their therapeutic potential.
…In the second sample, before the debriefing, we asked participants to guess whether they had taken a psychedelic, a placebo, or whether they were uncertain. Overall, 35% reported being certain they had taken a placebo, 12% were certain that they had taken a psychedelic, and the rest (53%) were uncertain. In the first sample, we did not ask this question, but the same number of people spontaneously reported being certain that they had taken a psychedelic drug. During the debriefing, when we revealed the placebo nature of the study, many participants appeared shocked. Several gasped and started laughing. One stated, “It’s very funny!”, and another replied, “It’s sad!” One of the participants who had sat with a group near the paintings throughout the study asked, “So we were all sober and just watching these paintings for 45 minutes‽”
[”This is a remarkable study, and probably the most elaborate placebo ever reported. But how well did the trick work? The authors say that after they revealed the truth, some of the participants expressed shock. However, 35% of them said they were “certain” they had taken a placebo when quizzed just before the debriefing. Only 12% were “certain” that they’d taken a real psychedelic drug, which suggests that the deception was only partially successful.
Some of the participants did report very strong effects on a questionnaire of ‘psychedelic effects’. However, I noticed that the effects reported tended to be the more abstract kind, such as “insight” and “bliss”. In terms of actual hallucinogenic effects like ‘complex imagery’ and ‘elementary imagery’ (ie. seeing things), no participants reported effects equal to even a low dose of LSD, let alone a stronger dose. See the rather confusing Figure 2 for details.” —Neuroskeptic]