In a blinded test, psilocybin mushroom microdoses caused felt effects but no lasting boost to well-being, creativity, or thinking beyond placebo
A 2022 study gave healthy adults who were new to microdosing real psilocybin mushroom doses and identical dummy doses, without telling them which was which, to test the effects.
Microdosing means taking psychedelic doses too small to feel like a full trip, and many people say it lifts mood, creativity, and focus. This study put that claim to the test. Thirty-four healthy adults new to microdosing each took a real 0.5-gram dose of dried psilocybin mushrooms and a matching dummy dose, without knowing which was which. The real dose caused some noticeable in-the-moment effects and shifted brain-wave readings, but it did not improve well-being, creativity, or thinking beyond the dummy dose. Tellingly, the stronger felt effects appeared only in people who correctly guessed they had taken the real dose, which points to expectation as part of what is going on.
In a within-subject, double-blind, placebo-controlled design, 34 healthy adults (11 female; mean age 31.3 years) who were beginning to microdose each received both 0.5 g of dried Psilocybe cubensis and a matching placebo. The investigators measured acute and short-term effects on subjective experience, creativity (divergent and convergent thinking), perception, cognition, and EEG brain activity. Reported acute effects were significantly more intense for the active dose than placebo, but only among participants who correctly identified their experimental condition. The active dose was accompanied by reduced EEG theta-band (4–8 Hz) power alongside preserved Lempel-Ziv broadband signal complexity. Creativity and self-reported well-being showed no significant between-condition differences; the only cognitive changes were a few small decrements toward impairment.
The authors caution that their two-doses-per-week design could not capture the cumulative effects of microdosing sustained over longer periods, which is how the practice is generally conducted. They also note the sample was healthy volunteers, so the absence of benefit could reflect ceiling effects, and that using whole mushrooms raises problems of unknown or inconsistent chemical composition. Beyond the authors' own caveats, the sample was small (34 people) and drawn from the general population — healthy adults new to microdosing, not a clinical or veteran group — and outcomes were assessed acutely and short-term, without long-term follow-up. The study was publicly funded (Argentine and Czech science agencies), and the authors declared no competing interests.
In this double-blind placebo-controlled study, the reported acute effects were significantly more intense for the active dose than placebo only among participants who correctly identified their experimental condition (Cavanna et al., 2022).
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