Microdosing psychedelics: personality, mental health, and creativity differences in microdosers
Psychopharmacology January 2, 2019 Thomas Anderson, Rotem Petranker, Daniel Rosenbaum et al. 171 citations
No Summary
Thomas Anderson
Department of Psychology, University of Toronto, Toronto, ON, Canada.
11 papers in the library · 478 citations · publishing 2018-2026
Papers
Psychedelic microdosing benefits and challenges: an empirical codebook
Harm Reduction Journal July 9, 2019 Thomas Anderson, Rotem Petranker, Adam Christopher et al. 130 citations
A mixed-methods study of an active microdosing community categorizes the experiences participants report, identifying high-potential avenues for future scientific research. The resulting taxonomy distills intervention targets from participant reports to help allocate research funding efficiently. Microdosing research complements full-dose psychedelic studies as clinical treatments and neuropharmacological mechanisms are developed. The framework aims to guide researchers and clinicians as experimental microdosing research begins in earnest.
Microdosing psychedelics: Demographics, practices, and psychiatric comorbidities
Journal of Psychopharmacology February 28, 2020 Daniel Rosenbaum, Cory R. Weissman, Thomas Anderson et al. 75 citations
People who microdose psychedelics—taking small, non-hallucinogenic amounts of LSD or psilocybin—are less likely to report a history of substance use disorders or anxiety disorders than non-microdosers, but more likely to report recent recreational substance use. Among 909 participants recruited from Reddit, most microdosers used LSD (59.3%) or psilocybin (25.9%) on a one-day-on, two-days-off schedule. The findings suggest that microdosers differ from non-microdosers in psychiatric and substance-use profiles, and well-designed randomized controlled trials are needed to evaluate safety and potential benefits in clinical populations.
Microdosing psychedelics: Subjective benefits and challenges, substance testing behavior, and the relevance of intention
Journal of Psychopharmacology October 8, 2020 Rotem Petranker, Thomas Anderson, Larissa J. Maier et al. 57 citations
In a large online survey of 6,753 people who had microdosed psychedelics in the past year, most reported enhanced mood, creativity, focus, and sociability, and the most common challenge was 'None'. Contrary to expectations, having an approach-intention—microdosing to achieve a specific goal—predicted fewer rather than more benefits. Most participants did not test their substances. The perceived benefits greatly outweighed the challenges, but double-blind, placebo-controlled experiments are needed to confirm these self-reported effects.
Keeping the promise: a critique of the current state of microdosing research
Frontiers in Psychiatry February 5, 2024 Rotem Petranker, Thomas Anderson, Youval Aberman et al. 14 citations
Microdosing, the practice of taking small, sub-hallucinogenic doses of psychedelics, has become popular, with users reporting benefits like improved mood and creativity. A review of 15 papers published before March 2022 critically analyzed the research practices in this field. The review concludes that it is premature to draw any conclusions about the efficacy or safety of microdosing because the quality of the research is not confirmatory. The authors propose potential causes for this state of the literature and offer suggestions for improvement.
Global Drug Survey
April 12, 2020 Rotem Petranker, Thomas Anderson, Larissa J. Maier et al. 14 citations preprint
A large survey of 6,753 people who microdosed LSD or psilocybin at least once in the past year found that the most commonly reported benefits were enhanced mood, creativity, focus, and sociability, partially replicating earlier findings. Most participants reported no challenges from microdosing, and the majority did not test their substances for purity. Contrary to expectations, microdosing with the intention of approaching a desired goal predicted fewer rather than more benefits. The authors conclude that the reported benefits outweigh the challenges, but emphasize that double-blind, placebo-controlled experiments are needed to confirm these self-reported effects.
Microdosing Psychedelics: Personality, mental health, and creativity differences in microdosers
November 1, 2018 Thomas Anderson, Rotem Petranker, Daniel M. Rosenbaum et al. 11 citations preprint
People who regularly consume small amounts of psychedelics like LSD or psilocybin—a practice called microdosing—report lower levels of dysfunctional attitudes and negative emotionality, and higher levels of wisdom, open-mindedness, and creativity compared to those who do not microdose. This pre-registered study, the first to investigate microdosing and mental health, recruited participants from online forums. Although promising, the findings are preliminary and warrant controlled experimental research to test safety and clinical efficacy. Microdosing may offer clinical benefits without the hallucinogenic effects of full-dose psychedelic therapy.
Microdosing as a response to the meaning crisis
May 26, 2020 Rotem Petranker, Juensung J. Kim, Thomas Anderson 4 citations preprint
People who microdose psychedelics like LSD or magic mushrooms do so mainly for clinical reasons and to boost productivity, but often struggle with unknown optimal dosing. Outcomes vary widely, from strong endorsement to disappointment at no effect. The analysis of 118 survey responses identified four themes: reasons, practice, outcomes, and meta-commentary, which included warnings against overexcitement. The findings suggest that even low doses may provide a sense of meaning lacking in Western culture, likely through enhanced psychological flexibility and connectedness, though placebo-controlled experiments are needed to confirm.
A Case of Stress-Induced Cardiomyopathy After Ketamine Infusion.
Cureus May 1, 2024 Zach Hart, Thomas Anderson, Hanna Fanous et al. 2 citations
A 64-year-old woman with hypothyroidism and parotid sarcoidosis developed acute chest pain and shortness of breath after receiving a ketamine infusion for mental health treatment. Echocardiography showed a temporarily reduced ejection fraction and apical hypokinesis, and angiography found no blocked coronary arteries, consistent with stress-induced cardiomyopathy. The timing suggests ketamine may have triggered the cardiomyopathy. Ketamine is increasingly used for depression and substance use disorders, but caution is warranted in patients with cardiovascular disease, and more research on its cardiac effects is needed.
Safety and Efficacy of Microdosing Psilocybin over 8 Weeks for Major Depressive Disorder: A Randomized Clinical Trial
Research Square February 23, 2026 Rotem Petranker, Norman Farb, Omer A. Syed et al.
Repeated low doses of psilocybin were safe and well tolerated in adults with major depressive disorder but did not show greater antidepressant effects than placebo. In a randomized, double-blind trial, 39 participants received either 2 mg psilocybin or placebo weekly for four weeks. Both groups reported similar reductions in depression scores on the PHQ-9 (psilocybin: -5.4; placebo: -6.0) and other measures. The microdose-first group showed slightly more improvement on a dysfunctional attitudes scale than the placebo-first group. No serious adverse events occurred, and symptom reductions continued during an open-label phase. Trial participation itself contributed to clinically meaningful improvement.
Microdosing Psilocybin for Major Depressive Disorder: Study Protocol for a Phase II Double-Blind Placebo-Controlled Randomized Partial Crossover Trial
November 16, 2025 Zeina Beidas, Anya Ragnhildstveit, Adam Blackman et al. preprint
A phase II trial will test whether microdosing psilocybin (2 mg weekly) outperforms placebo for major depressive disorder. Forty adults will receive either psilocybin or placebo for four weeks, then all will receive psilocybin for another four weeks. Depression symptoms and other measures will be assessed at baseline, after four weeks, and after eight weeks, with follow-ups for two years. The study aims to clarify whether microdosing has genuine antidepressant effects or whether benefits are due to expectancy, and to inform future dose regimens and the therapeutic role of sub-threshold versus threshold doses.