Microdosing Psychedelics: Harmful or a Positive Trend? – A Systematic Review and Current Status in The Netherlands

Abstract

Abstract Over the last years, microdosing psychedelics has become a popular theme in media and scientific research. This systematic review summarizes empirical research on microdosing psychedelics up to date. In total, 42 studies published between 1958 and 2022 are reviewed and categorized into experimental studies, qualitative studies, prospective survey studies, and retrospective survey studies. Reported effects are classified as positive or negative effects, depending on if the effect has a positive or negative effect on the individual. The results are summarized in the categories mood; well-being and energy; personality; and creativity and cognition. Most experimental studies included a placebo as comparator and only examined the acute effects of a single dose of psychedelics. Experimental studies found positive effects on mood, sociality and cognition, and negative effects on anxiety, physical effects, and consciousness. Self-report studies found positive effects on mood, attention, and well-being, and negative effects on anxiety, physical effects, and cognition. Thus, the effects of microdosing in the experimental and self-report studies are quite similar. However, the effects of microdosing seem to be related to expectations, suggesting that this might be a placebo effect. In addition, the literature shows a lot of inconsistencies in the dose ranges that are used. Mainly self-report studies do not mention the dose ranges, which makes it difficult to compare the results of those studies to each other. On the other hand, experimental studies mainly focus on the acute effects of microdosing, whereas microdosing is often done for a longer period of time. Future studies should therefore focus on the long-term effects of microdosing psychedelics, and always take the dose of the psychedelics into account.