Introduction: Microdosing refers to the repetitive administration of tiny doses of psychedelics (LSD, Psilocybin) over an extended period of time. This practice has been linked to alleged cognitive benefits, such as improved mood and creativity, potentiated by targeting serotonergic 5-HT2A receptors and facilitating cognitive flexibility. Nonetheless, in the absence of robust, quantitative and double-blind research on the effect of microdosing, such claims remain anecdotal.Methods: Here, our main aim was to quantitatively explore the effect of microdosing psychedelic truffles on two creativity tasks assumed to rely on separable processes: the Picture Concept Task assessing convergent thinking and the Alternative Uses Task assessing divergent thinking. We present results from 3 double-blind placebo-controlled longitudinal trials (of which one was pre-registered) conducted in a semi-naturalistic setting. Furthermore, we controlled for expectation and learning biases, and the data were mega-analyzed across trials with a pooled sample of 175 participants in order to maximize statistical power.Results: In the final analyses we found that active microdosing increased the ratio of original responses (originality/fluency), indicating higher quality of divergent answers in the active microdosing condition. The unadjusted originality score was significantly more pronounced in the active microdosing condition, but only when relative dosage (dose/weight of participants) was considered. These effects were present after controlling for expectation and demographic biases. No effects of active microdosing were found for convergent thinking or any other divergent-thinking score. The results suggest that the effects of truffle mirodosing are limited to divergent quality and are more subtle than initially anticipated. Our findings furthermore highlighted the importance of controlling for expectation biases, placebo effects, and prior psychedelic experience in microdosing practice and research.

RationaleThere has been a recent increase in research showing that classical serotonergic psychedelic (CSP) drugs may be used to ameliorate certain health issues and disorders. Here we hypothesized that CSP experiences, through their ability to induce awe and ego-dissolution, may result in a reduction of maladaptive narcissistic personality traits, such as a strong sense of entitlement and lack of empathy. ObjectivesOur objective was to investigate whether high levels of awe and ego dissolution during recent CSP experiences are associated with current lower levels of maladaptive narcissism.Methods In this pre-registered high-powered (N = 414) study, we used an online survey including several validated scales to test our hypothesis. ResultsA statistically significant mediation model indicated that recent CSP-induced awe experiences were associated with increased feelings of connectedness and affective empathetic drive, which in turn were associated with decreased exploitative-entitled narcissism. This relationship held even when taking into account sensation-seeking personality features. We found no evidence for feelings of ego dissolution during the experience to have the same effect. ConclusionsFeelings of awe, but not ego dissolution, during recent CSP experiences were associated with increased feelings of connectedness and empathy, which in turn were associated with decreased levels of maladaptive narcissism personality features. This suggests that there is a therapeutic potential of CSPs for disorders involving connectedness and empathy, such as the treatment of pathological narcissism and other clinical disorders, and that the induction of connectedness through awe appears to be the driving force behind this potential.