Psychedelic Microdosing, Mindfulness, and Anxiety: A Cross-Sectional Mediation Study.

While anecdotal reports claim that psychedelic microdosing reduces anxiety and mood symptoms, evidence supporting these claims is scarce. This cross-sectional study investigated the association between microdosing and trait anxiety. Furthermore, it was investigated if trait mindfulness mediated this association. Participants completed anonymous online questionnaires and were divided into three groups: current microdosers ( = 186), former microdosers ( = 77) and microdosing-naïve controls ( = 234). Trait anxiety and trait mindfulness were measured using the State-Trait Anxiety Inventory - Trait subscale (STAI-T) and the 15-item Five-Facet Mindfulness Questionnaire (FFMQ-15) respectively. Current and former microdosers reported lower STAI-T scores compared to microdosing-naïve controls. Furthermore, associations of current and former microdosing with trait anxiety were mediated by trait mindfulness, with small effects of FFMQ-15 Total, Non-judging and Non-reactivity scores. However, in an exploratory analysis, all associations between microdosing and STAI-T scores became non-significant when participants with previous macrodose experience ( = 386) were excluded. Our findings suggest that RCTs are warranted to test causal hypotheses concerning the effects of microdosing and the role of trait mindfulness in the effects of microdosing, while controlling for previous macrodose experience.