School of Psychological Sciences, Macquarie University, Australia.
Turner Institute, School of Psychological Sciences, Monash University, Australia; Department of Psychiatry, School of Clinical Sciences, Monash University, Australia.
Neurosci Biobehav Rev. 2022 Aug;139:104706. doi: 10.1016/j.neubiorev.2022.104706. Epub 2022 May 21.
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.
低剂量致幻物质（微剂量）的使用正引起越来越多的关注。本系统综述总结了迄今为止所有的致幻物质微剂量研究，包括一组在禁令之前进行的鲜为人知的研究。具体来说，我们回顾了 1955 年至 2021 年间发表的 44 项研究，并总结了报告的六个类别的影响：情绪和心理健康；幸福感和态度；认知和创造力；个性；意识状态变化；和神经生物学与生理学。研究表明，设计、年龄和其他研究特征取决于研究的偏倚风险程度。实验室研究发现，疼痛感知、时间感知、意识状态和神经生理学发生变化。自我报告的研究发现认知加工和心理健康的变化。我们回顾了与期望和安慰剂效应相关的数据，但认为微剂量效应主要归因于期望的说法还为时过早，而且可能是错误的。此外，我们试图通过提供不同物质的建议剂量范围来澄清微剂量文献中的定义不一致问题。最后，我们提供了具体的设计建议，以促进未来更严格的研究。
