The emerging science of microdosing: A systematic review of research on low dose psychedelics (1955 - 2021)
This preprint (2021) review is one of the most comprehensive reviews on microdosing to date. The reviewers report effects across six categories; mood and mental health; wellbeing and attitude; cognition and creativity; personality; changes in conscious state; and neurobiology and physiology. Studies showed a wide range in risk of bias and argue that the idea that the effects of microdosing are due to expectancy is possibly wrong.
Abstract
The use of low doses of psychedelic substances (microdosing) is attracting increasing interest. This systematic review summarises all empirical microdosing research to date, including a set of infrequently cited studies that took place prior to prohibition. Specifically, we reviewed 44 studies published between 1955 and 2021, and summarised reported effects across six categories: mood and mental health; wellbeing and attitude; cognition and creativity; personality; changes in conscious state; and neurobiology and physiology. Studies showed a wide range in risk of bias, depending on design, age, and other study characteristics. Laboratory studies found changes in pain perception, time perception, conscious state, and neurophysiology. Self-report studies found changes in cognitive processing and mental health. We review data related to expectation and placebo effects, but argue that claims that microdosing effects are largely due to expectancy are premature and possibly wrong. In addition, we attempt to clarify definitional inconsistencies in the microdosing literature by providing suggested dose ranges across different substances. Finally, we provide specific design suggestions to facilitate more rigorous future research.
Research Summary of 'The emerging science of microdosing: A systematic review of research on low dose psychedelics (1955 - 2021)'
Introduction
Microdosing refers to the repeated ingestion of very low doses of psychedelic substances, most commonly LSD and psilocybin, typically practised with the aims of improving wellbeing, cognition, mood, or social functioning. Polito and colleagues note that microdosing has become substantially more visible in recent years through mainstream media, anecdotal reports, and commercial interest, yet the empirical literature remains fragmented and of variable quality. The authors highlight three practical difficulties that have complicated prior work: uncertain dose definitions across substances and individuals, variability in subjective thresholds for perceptual effects, and the use of unregulated substances by naturalistic microdosers. This paper sets out to systematically review all empirical human research on microdosing from 1955 through 18 April 2021. Rather than summarising only contemporary studies, Polito and colleagues include earlier pre‑prohibition research in which doses that would now be considered microdoses were administered. Their aim is to catalogue study characteristics, tabulate reported effects across key domains (mood and mental health; wellbeing and attitude; cognition and creativity; personality; changes in conscious state; neurobiology and physiology), assess risk of bias with a tailored tool, and offer design recommendations to strengthen future research.
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Polito, V., & Liknaitzky, P. (2021). The emerging science of microdosing: A systematic review of research on low dose psychedelics (1955 - 2021). https://doi.org/10.31234/osf.io/edhqz
References (49)
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Anderson, T., Petranker, R., Christopher, A. et al. · Harm Reduction Journal (2019)
Anderson, T., Petranker, R., Rosenbaum, D. et al. · Psychopharmacology (2019)
Andersson, M., Kjellgren, A. · Harm Reduction Journal (2019)
Andersson, M., Persson, M., Kjellgren, A. · Harm Reduction Journal (2017)
Beaton, B., Copes, H., Webb, M. et al. · Journal of Drug Issues (2019)
Bershad, A. K., Preller, K. H., Lee, R. et al. · Biological Psychiatry (2020)
Bershad, A. K., Schepers, S. T., Bremmer, M. P. et al. · Biological Psychiatry (2019)
Bornemann, J. · Journal of Psychoactive Drugs (2020)
Carhart-Harris, R. L., Goodwin, G. M. · Neuropsychopharmacology (2017)
Dressler, H. M., Bright, S. J., Polito, V. · Journal of Psychedelic Studies (2021)
Show all 49 referencesShow fewer
Erritzoe, D., Roseman, L., Nour, M. R. et al. · Acta Psychiatrica Scandinavica (2018)
Fadiman, J., Korb, S. · Journal of Psychoactive Drugs (2019)
Family, N., Maillet, E. L., Williams, L. T. J. et al. · Psychopharmacology (2019)
Forsyth, B., Machado, L., Jowett, T. et al. · Journal of Ethnopharmacology (2016)
Gasser, P., Holstein, D., Michel, Y. et al. · Journal of Nervous and Mental Disease (2014)
Griffiths, R. R., Johnson, M. W. · Journal of Psychopharmacology (2016)
Griffiths, R. R., Johnson, M. W., Richards, W. A. et al. · Journal of Psychopharmacology (2017)
Griffiths, R. R., Johnson, M. W., Richards, W. A. et al. · Psychopharmacology (2011)
Hasler, F., Grimberg, U., Benz, M. A. et al. · Psychopharmacology (2004)
Zhang, D. Z., Holze, F., Liechti, M. E. et al. · Clinical Pharmacology and Therapeutics (2020)
Holze, F., Vizeli, P., Müller, F. et al. · Neuropsychopharmacology (2019)
Hutten, N. P. W., Mason, N. L., Dolder, P. C. et al. · International Journal of Neuropsychopharmacology (2019)
Hutten, N. R. P. W., Mason, N. L., Dolder, P. C. et al. · European Neuropsychopharmacology (2020)
Johnstad, P. G. · Nordic Studies on Alcohol and Drugs (2018)
Kaertner, L. S., Steinborn, M. B., Kettner, H. et al. · Scientific Reports (2021)
Kuypers, K. P. C. · Therapeutic Advances in Psychopharmacology (2020)
Kuypers, K. P. C. · Modern CNS Drug Discovery (2021)
Kuypers, K. P. C., Erritzoe, D., Knudsen, G. M. et al. · Journal of Psychopharmacology (2019)
Lea, T., Amada, N., Jungaberle, H. et al. · International Journal of Drug Policy (2020)
Lea, T., Jungaberle, H., Schecke, H. et al. · Psychopharmacology (2020)
Luethi, D., Hoener, M. C., Krähenbühl, S. et al. · Biochemical Pharmacology (2019)
Madsen, M. K., Fisher, P. M., Burmester, D. et al. · Neuropsychopharmacology (2019)
Moreno, F. A., Wiegand, C. B., Taitano, E. K. et al. · Journal of Clinical Psychiatry (2006)
Mueller, F., Lenz, C., Dolder, P. C. et al. · Translational Psychiatry (2017)
Muthukumaraswamy, S., Forsyth, B., Lumley, T. · Expert Review of Clinical Pharmacology (2021)
Nichols, D. E. · Pharmacological Reviews (2016)
Nutt, D. J., Erritzoe, D., Carhart-Harris, R. L. · Cell (2020)
Ona, G., Bouso, J. C. · Neuroscience and Biobehavioral Reviews (2020)
Polito, V., Stevenson, R. J. · PLOS ONE (2019)
Prochazkova, L., Lippelt, D. P., Colzato, L. S. et al. · Psychopharmacology (2018)
Ramaekers, J. G., Hutten, N. P. W., Mason, N. L. et al. · Journal of Psychopharmacology (2020)
Rosenbaum, D., Weissman, C. R., Anderson, T. et al. · Journal of Psychopharmacology (2020)
Sewell, R. A. · Neurology (2006)
Studerus, E., Gamma, A., Vollenweider, F. X. · PLOS ONE (2010)
Szigeti, B., Kartner, L., Blemings, A. et al. · eLife (2021)
Nutt, D. J., Carhart-Harris, R. L. · Current Drug Abuse Reviews (2015)
Wacker, D., Wang, S., Mccorvy, J. D. et al. · Cell (2017)
Wittmann, M., Hasler, F., Vollenweider, F. X. · Neuroscience Letters (2008)
Webb, M., Copes, H., Hendricks, P. S. · International Journal of Drug Policy (2019)
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