Microdosing psychedelic substances: demographics, psychiatric comorbidities, and comorbid substance use.

Rationale: Microdosing psychedelics – the practice of consuming small, sub-hallucinogenic doses of substances
such as LSD or psilocybin – is gaining attention in popular media but remains poorly characterized. Contemporary
studies of psychedelic microdosing have yet to report the basic psychiatric descriptors of psychedelic microdosers.
Objectives: To examine the practices and demographics of a population of psychedelic microdosers – including their
psychiatric diagnoses, prescription medications, and recreational substance use patterns – to develop a foundation on
which to conduct future clinical research.
Methods: Participants (n=909; Mage=26.9, SD=8.6; male=83.2%; White/European=79.1%) recruited primarily from
the online forum Reddit completed an anonymous, online survey. Respondents who reported using LSD, psilocybin,
or both for microdosing were grouped and compared to non-microdosing controls using exploratory odds ratio
testing on demographic variables, rates of psychiatric diagnoses, and past-year recreational substance use.
Results: Of microdosers, most reported using LSD (59.3%; Mdose=13 mcg, or 11.3% of one tab) or psilocybin
(25.9%; Mdose=0.3 g of dried psilocybin mushrooms) on a one-day-on, two-days-off schedule. Compared with
controls, microdosers were significantly less likely to report a history of Substance Use Disorders (OR = 0.17 (95%
CI: 0.05-0.56)) or Anxiety Disorders (OR = 0.61 (95% CI: 0.41-0.91)). Microdosers were also more likely to report
recent recreational substance use compared with controls (OR = 5.2 (95% CI: 2.7-10.8)).
Conclusions: Our population of psychedelic microdosers reported clinically-significant rates of various psychiatric
diagnoses, psychotropic medication prescription, and recreational substance use. Well-designed randomized
controlled trials are needed to evaluate the safety and tolerability of this practice in clinical populations and to test
claims about potential benefits.


Rosenbaum, D., Weissman, C., Hapke, E., Hui, K., Petranker, R., Dinh-Williams, L.-A., & Anderson, T. (2019). Microdosing psychedelic substances: Demographics, psychiatric comorbidities, and comorbid substance use. Manuscript in preparation. Accepted to Journal of Psychopharmacology. Preprint available at

July 10, 2019

Psychedelic microdosing benefits and challenges: an empirical codebook

Background: Microdosing psychedelics is the practice of consuming very low, sub-hallucinogenic doses of a psychedelic substance, such as lysergic acid diethylamide (LSD) or psilocybin-containing mushrooms. According to media reports, microdosing has grown in popularity, yet the scientific literature contains minimal research on this practice. There has been limited reporting on adverse events associated with microdosing, and the experiences of microdosers in community samples have not been categorized.

Methods: In the present study, we develop a codebook of microdosing benefits and challenges (MDBC) based on the qualitative reports of a real-world sample of 278 microdosers.

Results: We describe novel findings, both in terms of beneficial outcomes, such as improved mood (26.6%) and focus (14.8%), and in terms of challenging outcomes, such as physiological discomfort (18.0%) and increased anxiety (6.7%). We also show parallels between benefits and drawbacks and discuss the implications of these results. We probe for substance-dependent differences, finding that psilocybin-only users report the benefits of microdosing were more important than other users report.

Conclusions: These mixed-methods results help summarize and frame the experiences reported by an active microdosing community as high-potential avenues for future scientific research. The MDBC taxonomy reported here informs future research, leveraging participant reports to distil the highest-potential intervention targets so research funding can be efficiently allocated. Microdosing research complements the full-dose literature as clinical treatments are developed and neuropharmacological mechanisms are sought. This framework aims to inform researchers and clinicians as experimental microdosing research begins in earnest in the years to come.

Anderson, T., Petranker, R., Christopher, A., Rosenbaum, D., Weissman, C., Dinh-Williams, L.-A., Hui, K., & Hapke, E. (2019). Psychedelic microdosing benefits and challenges: An empirical codebook. Harm Reduction Journal, 16(1), 43.

January 2, 2019

Microdosing psychedelics: personality, mental health, and creativity differences in microdosers

Rationale: Microdosing psychedelics—the regular consumption of small amounts of psychedelic substances such as LSD or psilocybin—is a growing trend in popular culture. Recent studies on full-dose psychedelic psychotherapy reveal promising benefits for mental well-being, especially for depression and end-of-life anxiety. While full-dose therapies include perception-distorting properties, microdosing may provide complementary clinical benefits using lower-risk, non-hallucinogenic doses.
Objectives: This pre-registered study aimed to investigate whether microdosing psychedelics is related to differences in personality, mental health, and creativity.
Methods: In this observational study, respondents recruited from online forums self-reported their microdosing behaviours and completed questionnaires concerning dysfunctional attitudes, wisdom, negative emotionality, open-mindedness, and mood. Respondents also performed the Unusual Uses Task to assess their creativity.
Results: Current and former microdosers scored lower on measures of dysfunctional attitudes (p < 0.001, r = − 0.92) and negative emotionality (p = 0.009, r = − 0.85) and higher on wisdom (p < 0.001, r = 0.88), open-mindedness (p = 0.027, r = 0.67), and creativity (p < 0.001, r = 0.15) when compared to non-microdosing controls.
Conclusions: These findings provide promising initial evidence that warrants controlled experimental research to directly test safety and clinical efficacy. As microdoses are easier to administer than full-doses, this new paradigm has the exciting potential to shape future psychedelic research.

Anderson, T., Petranker, R., Rosenbaum, D., Weissman, C. R., Dinh-Williams, L.-A., Hui, K., Hapke, E., & Farb, N. A. S. (2019). Microdosing psychedelics: Personality, mental health, and creativity differences in microdosers. Psychopharmacology, 236(2), 731–740.

©2020 by Canadian Centre for Psychedelic Science Inc.