Subscribe
The latest psychology and neuroscience discoveries.
My Account
  • Mental Health
  • Social Psychology
  • Cognitive Science
  • Psychopharmacology
  • Neuroscience
  • About
No Result
View All Result
PsyPost
PsyPost
No Result
View All Result
Home Exclusive Psychopharmacology Psychedelic Drugs Microdosing

Placebo-controlled study suggests that the benefits of psilocybin microdosing can be explained by expectancy effects

by Beth Ellwood
September 6, 2022
in Microdosing, Psilocybin
(Photo credit: Adobe Stock)

(Photo credit: Adobe Stock)

Share on TwitterShare on Facebook

Anecdotal evidence suggests that microdosing with psilocybin mushrooms offers mental health benefits. But a recent experimental study suggests that these purported benefits may be driven by users’ expectations. Findings from the placebo-controlled experiment were published in the journal Translational Psychiatry.

Microdosing, the practice of consuming low, sub-hallucinogenic doses of psychedelics, appears to be growing in popularity among the public. People who engage in microdosing often do so for the potential mental health benefits, hoping the practice will improve their mood, concentration, cognitive function, and even creativity. However, there is currently little experimental research on the effects of microdosing with psychedelics.

In an experimental study, Federico Cavanna and colleagues tested the effects of microdosing with psilocybin — a compound found in psychoactive mushrooms that is commonly used for microdosing. Importantly, the study authors controlled for participant and experimenter expectancy effects, which is when the expectations of participants and researchers influence the results of the study.

The researchers recruited 34 participants (11 women) who were already planning to start a microdosing protocol. The experiment involved two weeks of measurements. During one week, participants were given two doses of 0.5 g of dried psilocybin mushrooms. During another week, participants were given two doses of placebo of the same weight and preparation. The experiment was double-blind, which meant that the conditions were organized by a third party, and neither the experimenters nor the participants knew if subjects were given a placebo or psilocybin capsule.

Participants completed a self-report questionnaire where they reported the acute effects they experienced with the doses (e.g., “My sense of space and size was distorted”) and completed psychological measures including anxiety, positive and negative affect, well-being, and stress. They also completed several tasks assessing creativity, perception, and cognition, and their brain activity was measured with electroencephalography (EEG). Finally, participants reported their expectations for how their mental state might change in various areas (e.g., positive emotion, anxiety).

The results revealed significant effects on the self-report questionnaire, where participants taking psilocybin reported higher acute effects compared to those taking placebo. However, these results were only significant among subjects who had correctly identified which condition they were in — in other words, subjects who correctly identified whether or not they were taking psilocybin. This suggests that the observed subjective effects were driven by participants’ expectations.

While the EEG results revealed altered EEG rhythms, the study failed to reveal any positive impact of psilocybin on subjects’ creativity, cognition, or self-reported mental well-being. By contrast, a trend in the results suggested that the psilocybin may have hindered performance on certain cognitive tasks. The authors note that this trend is in line with past evidence suggesting that stronger doses of serotonergic hallucinogens can be detrimental to cognitive functioning, for example, by impairing attention and decision-making.

Overall, the results did not support previous evidence that microdosing improves well-being, creativity, or cognitive function. However, there were several limitations to the study which may have impacted the findings.

For one, the experiment involved a short-term microdosing schedule of two doses per week. Future studies should test whether microdosing over an extended period may have a stronger effect on mental health. Additionally, the sample was comprised of healthy participants, and it could be that microdosing with psilocybin only produces positive benefits among patients suffering from mental health issues. The authors say additional research is needed to determine whether microdosing truly offers mental health benefits, and to gain a clearer picture of its safety.

The study, “Microdosing with psilocybin mushrooms: a double-blind placebo-controlled study”, was authored by Federico Cavanna, Stephanie Muller, Laura Alethia de la Fuente, Federico Zamberlan, Matías Palmucci, Lucie Janeckova, Martin Kuchar, Carla Pallavicini, and Enzo Tagliazucchi.

TweetSendScanShareSendPin2ShareShareShareShareShare

RELATED

Antidepressants may diminish psilocybin’s effects even after discontinuation
Depression

A single dose of psilocybin might help reduce symptoms in treatment-resistant depression

May 12, 2025

A new open-label study suggests that a single dose of psilocybin, combined with psychological support, may reduce symptoms in people with severe treatment-resistant depression. Improvements were sustained for up to 12 weeks, although effects were weaker in those with PTSD.

Read moreDetails
Psilocybin use has surged in the United States since 2019
Psilocybin

Psilocybin use has surged in the United States since 2019

May 10, 2025

Psilocybin use has surged across the U.S. in recent years, with the biggest increases seen among adults with depression, anxiety, and chronic pain.

Read moreDetails
Microdoses of LSD enhance neural complexity, study finds
Depression

Little-known psychedelic drug shows promise in treating low motivation in depression

May 9, 2025

Researchers investigating the psychedelic drug DOPR discovered that very low doses can enhance motivation in low-performing mice—without triggering behaviors linked to hallucinations. The findings point to the therapeutic potential of psychedelics at doses too low to alter perception.

Read moreDetails
A dose of psilocybin stirred the brain of a barely conscious woman
Neuroimaging

A dose of psilocybin stirred the brain of a barely conscious woman

May 7, 2025

In a groundbreaking case report, scientists administered psilocybin to a woman in a minimally conscious state and observed increased brain complexity and new spontaneous behavior—offering a glimpse into how psychedelics might influence consciousness in severe brain injury patients.

Read moreDetails
Psychedelic users tend to have greater objective knowledge about climate change, study finds
Parkinson's disease

Psilocybin shows promise for improving mood, cognition, and motor symptoms in Parkinson’s disease

May 1, 2025

Psilocybin therapy produced surprising benefits in a small study of people with Parkinson’s disease. Beyond improving mood, the psychedelic treatment was linked to better motor function and cognitive performance.

Read moreDetails
Psilocybin-assisted neurofeedback shows promise in preliminary research
Psilocybin

Psilocybin-assisted neurofeedback shows promise in preliminary research

April 3, 2025

A new study explores combining psilocybin microdosing with neurofeedback. The method appears feasible, though it’s unclear whether it meaningfully improves mental performance.

Read moreDetails
Study finds microdosing LSD is not effective in reducing ADHD symptoms
ADHD

Study finds microdosing LSD is not effective in reducing ADHD symptoms

March 23, 2025

Microdosing LSD has no clear benefit for ADHD, according to a new placebo-controlled clinical trial published in JAMA Psychiatry.

Read moreDetails
LSD reshapes the brain’s response to pain, neuroimaging study finds
LSD

Psychedelics use is linked to lower odds of frequent bad headaches

March 19, 2025

A study of British adults found that those who had used psychedelics were 25% less likely to report frequent bad headaches, adding to growing research on psychedelics’ potential medical benefits.

Read moreDetails

SUBSCRIBE

Go Ad-Free! Click here to subscribe to PsyPost and support independent science journalism!

STAY CONNECTED

LATEST

Neuroscientists challenge “dopamine detox” trend with evidence from avoidance learning

Non-right-handedness is more common across multiple mental health conditions

Withdrawal symptoms are common after stopping antidepressants

Anxious attachment linked to depression spillover in romantic relationships, study finds

Scientists find 16 new Alzheimer’s-linked genes using multi-ancestry genome data

Groundbreaking AI model uncovers hidden patterns of political bias in online news

Gut bacteria can influence how brain proteins are modified by carbohydrates

“Tiger mom” parenting boosts teens’ cognitive skills but undermines emotional development, study suggests

         
       
  • Contact us
  • Privacy policy
  • Terms and Conditions
[Do not sell my information]

Welcome Back!

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In

Add New Playlist

Subscribe
  • My Account
  • Cognitive Science Research
  • Mental Health Research
  • Social Psychology Research
  • Drug Research
  • Relationship Research
  • About PsyPost
  • Contact
  • Privacy Policy