Related Experiment Video
Updated: Jan 12, 2026

Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study
Published on: August 18, 2020
Microdosing psilocybin and its effect on creativity: Lessons learned from three double-blind placebo controlled
Luisa Prochazkova1, Josephine Marschall1, Michiel van Elk1
1Institute of Psychology, Leiden University, Wassenaarseweg 52, 2333, AK, Leiden, the Netherlands.
Background:
Taking very small doses of psychedelics (LSD, truffles) over an extended period became prevalent in Western societies for its alleged cognitive benefit, including enhanced creativity. However, in the absence of robust, double-blind-controlled quantitative studies, such claims remain anecdotal.
Methods:
Here we present results from 3 double-blind placebo-controlled longitudinal trials (one of which pre-registered) assessing the effects of microdosing psilocybin on convergent and divergent creativity in a well-controlled semi-naturalistic setting. To enhance statistical power and generalizability, data from all trials (N = 171) were pooled in a mega-analysis, resulting in one of the most robust laboratory-based studies on microdosing to date.
Results:
We found that active microdosing increased the ratio of original responses (originality/fluency), indicating higher quality of divergent thinking in the active microdosing condition. The unadjusted originality score was significantly more pronounced in the active microdosing condition, but only when relative dosage (dose/weight of participants) was considered. Importantly, these effects survived controlling for dose guess and demographic biases. No effects of active microdosing were found for other divergent-thinking scores or convergent thinking.
Conclusion:
The results suggest that the effects of truffle mirodosing are limited to the quality of divergent thinking. Moreover, our findings highlight the importance of controlling for placebo effects and prior psychedelic experience in assessing the impact of microdosing.
Related Concept Videos
Hallucinogens and Psychedelics
Marijuana, derived from the dried leaves and flowers of the hemp plant, contains...
The Placebo Effect
CNS Stimulants: Psychedelic Agents
Altered States of Awareness
The ingestion of substances like stimulants or hallucinogens leads to chemical alterations in the brain...
Blind Procedures

