Evidence map›Paper›PMID 42593636›Full record

SynthesisCNS drugs2026

Efficacy and Safety of Psychedelic Microdosing on Psychological Outcomes in Healthy Adults: A Systematic Review and Meta-analysis.

Shakila Meshkat, Marco Leung, Sarina Meshkat, Qiaowei Lin, Dillani Wijendran, Amy C Reichelt, Yanbo Zhang, Lisa Burback, Olga Winkler, Andrew Greenshaw and 6 more

Abstract readSystematic ReviewMeta-Analysis
PubMed Publisher
In one paragraph

Synthesis in CNS drugs, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

16 authors.

Shakila MeshkatArtificial Intelligence for Mental Health Program, St. Michael's Hospital, 193 Yonge Street 6-013, Toronto, ON, M5B 1M8, Canada.ORCID http://orcid.org/0000-0002-7010-1785
Marco LeungArtificial Intelligence for Mental Health Program, St. Michael's Hospital, 193 Yonge Street 6-013, Toronto, ON, M5B 1M8, Canada.
Sarina MeshkatArtificial Intelligence for Mental Health Program, St. Michael's Hospital, 193 Yonge Street 6-013, Toronto, ON, M5B 1M8, Canada.
Qiaowei LinArtificial Intelligence for Mental Health Program, St. Michael's Hospital, 193 Yonge Street 6-013, Toronto, ON, M5B 1M8, Canada.ORCID http://orcid.org/0009-0003-1884-4973
Dillani WijendranArtificial Intelligence for Mental Health Program, St. Michael's Hospital, 193 Yonge Street 6-013, Toronto, ON, M5B 1M8, Canada.
Amy C ReicheltDepartment of Physiology and Pharmacology, Western University, London, Canada.ORCID http://orcid.org/0000-0002-0637-0411
Yanbo ZhangDepartment of Psychiatry, University of Alberta, Edmonton, AB, Canada.ORCID http://orcid.org/0000-0002-2421-157X
Lisa BurbackDepartment of Psychiatry, University of Alberta, Edmonton, AB, Canada.ORCID http://orcid.org/0000-0001-9591-4355
Olga WinklerDepartment of Psychiatry, University of Alberta, Edmonton, AB, Canada.ORCID http://orcid.org/0000-0001-7297-1250
Andrew GreenshawDepartment of Psychiatry, University of Alberta, Edmonton, AB, Canada.ORCID http://orcid.org/0000-0002-9097-900X
Candice M MonsonDepartment of Psychology, Toronto Metropolitan University, Toronto, ON, Canada.ORCID http://orcid.org/0000-0001-6179-0788
Eric VermettenDepartment of Psychiatry, Leiden University Medical Center, Leiden, The Netherlands.ORCID http://orcid.org/0000-0003-3040-7162
Rakesh JetlyInstitute of Mental Health Research, University of Ottawa, Ottawa, ON, Canada.ORCID http://orcid.org/0000-0001-6610-9365
Wendy LouDepartment of Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.ORCID http://orcid.org/0000-0001-5590-8719
Richard J ZeifmanDepartment of Psychology, The New School for Social Research, New York, NY, USA.ORCID http://orcid.org/0000-0003-3478-4483
Venkat BhatArtificial Intelligence for Mental Health Program, St. Michael's Hospital, 193 Yonge Street 6-013, Toronto, ON, M5B 1M8, Canada. venkat.bhat@utoronto.ca.ORCID http://orcid.org/0000-0002-8768-1173

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundPsychedelic microdosing has gained increasing popularity for enhancing mood and cognition, yet its effects on psychological outcomes in healthy adults remain unclear. We aim to evaluate the efficacy and safety of psychedelic microdosing on psychological outcomes in healthy/non-clinical adult population.

methodsThis review was registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD420251035294). We searched Embase, MEDLINE, and PsycINFO from inception to February 2026 for original studies in healthy adults using sub-hallucinogenic psychedelic doses on separate days. We included randomized studies, nonrandomized prospective studies, cross-sectional studies, and observational longitudinal designs and stratified meta-analyses by design. Random-effects models were used; safety in randomized controlled trials (RCTs) was pooled as risk differences (RDs). Risk of bias was assessed using the Joanna Briggs Institute (JBI) critical appraisal tools appropriate for each study design.

results24 studies (3,681 participants) met inclusion criteria, 6 contributed to meta-analyses. RCTs of psilocybin and LSD microdosing showed subjective and neurophysiological effects but minimal impact on cognition, creativity, or sustained mood. Psilocybin altered EEG and speech with little behavioral change, while LSD caused transient mood and minor physiological effects without lasting cognitive or personality benefits. Observational studies indicated mood and personality improvements, likely influenced by expectancy or lifestyle factors. Meta-analyses included two parallel RCTs (3 comparisons; n = 117) and three non-RCT studies (n = 1,013). Adverse event analyses included two RCTs (4 comparisons; n = 109). RCTs showed no clear evidence of immediate symptom reduction: depressive symptoms (SMD = -0.19; 95% CI -0.56, 0.19; I

conclusionsMicrodosing does not show consistent immediate benefits for depressive, anxiety, or stress symptoms in healthy adults, and evidence from RCTs remains inconclusive. Although improvements were observed in some studies, these effects were not significantly different from placebo. Larger, well-designed RCTs are needed to clarify the efficacy and safety of psychedelic microdosing beyond placebo.

Indexed as

HallucinogensLysergic Acid DiethylamidePsilocybinAdultAffectCognitionCognitive EnhancementHumansRandomized Controlled Trials as TopicHallucinogensLysergic Acid DiethylamidePsilocybin

Identifiers

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.