The emerging science of microdosing: A systematic review of research on low dose psychedelics (1955–2021) and recommendations for the field
Neuroscience & Biobehavioral Reviews May 21, 2022 DOI: 10.1016/j.neubiorev.2022.104706 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Systematic review Peer reviewed |
|---|---|
| Sample size | 44 |
| Population | Human participants in microdosing studies |
| Topics | Microdosing |
| Keywords | Expectancy theory Mood Cognition Mental health Perception Clinical psychology Applied psychology Psychotherapist |
| Citations | 110 |
| Key findings | Microdosing psychedelics is associated with changes in pain perception, time perception, conscious state, neurophysiology, cognitive processing, and mental health, and claims that effects are largely due to expectancy are premature and 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.
Comparable studies
Other systematic reviews and meta-analyses on microdosing, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| The utility of microdosing over the past 5 years Drugs with published comparisons of microdose and therapeutic dose pharmacokinetics | 2008 | Systematic review | n = 18 |
| The therapeutic potential of microdosing psychedelics in depression Healthy volunteers and patient samples | 2020 | Systematic review | |
| Potential safety, benefits, and influence of the placebo effect in microdosing psychedelic drugs: A systematic review | 2020 | Systematic review | |
| Microdosing Psychedelics: Current Evidence From Controlled Studies. Healthy adults | 2024 | Systematic review | |
| Keeping the promise: a critique of the current state of microdosing research | 2024 | Systematic review |
Citations in the library
Cited by 91
- Assessing expectancy and suggestibility in a trial of escitalopram v. psilocybin for depression. Psychological Medicine June 1, 2024
- Acute Mood-Elevating Properties of Microdosed Lysergic Acid Diethylamide in Healthy Volunteers: A Home-Administered Randomized Controlled Trial. Biological Psychiatry September 15, 2023
- Low doses of lysergic acid diethylamide (LSD) increase reward-related brain activity. Neuropsychopharmacology 2023
- Repeated low doses of psilocybin increase resilience to stress, lower compulsive actions, and strengthen cortical connections to the paraventricular thalamic nucleus in rats. Molecular Psychiatry September 1, 2023
- The costs and benefits of psychedelics on cognition and mood Neuron January 20, 2023
and 86 more in the library
Cites 64
- Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial Journal of Psychopharmacology November 30, 2016
- Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects. Psychopharmacology December 1, 2011
- Safety, Tolerability, and Efficacy of Psilocybin in 9 Patients With Obsessive-Compulsive Disorder The Journal of Clinical Psychiatry November 15, 2006
- Safety and Efficacy of Lysergic Acid Diethylamide-Assisted Psychotherapy for Anxiety Associated With Life-threatening Diseases The Journal of Nervous and Mental Disease March 4, 2014
- Psychometric Evaluation of the Altered States of Consciousness Rating Scale (OAV) PLoS One August 31, 2010
and 59 more in the library