In this paper, we present the development of the Altered States Database (ASDB), an open-science project based on a systematic literature review. The ASDB contains psychometric questionnaire data on subjective experiences of altered states of consciousness (ASC) induced by pharmacological and non-pharmacological methods. The systematic review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Scientific journal articles were identified through PubMed and Web of Science. We included studies that examined ASC using the following validated questionnaires: Altered States of Consciousness Rating Scale (APZ, 5D-ASC, 11-ASC), Phenomenology of Consciousness Inventory (PCI), Hallucinogen Rating Scale (HRS), or Mystical Experience Questionnaire (MEQ30). The systematic review resulted in the inclusion of a total of 165 journal articles, whereof questionnaire data was extracted and is now available on the Open Science Framework (OSF) website (https://osf.io/8mbru) and on the ASDB website (http://alteredstatesdb.org), where questionnaire data can be easily retrieved and visualized. This data allows the calculation of comparable psychometric values of ASC experiences and of dose-response relationships of substances inducing ASC.

Background and aimsPrevious research has proposed that microdosing, i.e., the repeated use of sub-threshold doses of serotonergic hallucinogens, has an impact on mood by increasing emotional awareness. We propose that increased emotional awareness could translate into higher emodiversity, a balanced experience of emotions in which emotions are experienced with more similarity in intensity and duration. We examine the effect of microdosing, the day after, as well as the cumulative effect of microdosing on overall, positive and negative emodiversity.MethodsWe use data collected over a period of 28 days sampled between February to June 2020 from 18 users that already had an active practice of microdosing at the start of the data collection. We assessed emotional states using ESM methods, i.e., signal-contingent sampling with triggers sent 5 times a day. The working dataset has a number of 224 observations days. We used mixed effects models to test our hypotheses.ResultsWhen taking into account the level of average affect, we found that during microdosing days positive and overall emodiversity were significantly lower. No evidence was found for a mediating role of the level of average affect. Higher cumulative instances of microdosing were not related to any of the emodiversity indexes. Participants experienced more “awe, wonder, or amazement”, “ashamed, humiliated, or disgraced” as well as less “joyful, glad, or happy” emotions during microdosing days.ConclusionA microdosing practice may increase the centrality of certain emotions on microdosing days, resulting in a decrease in emotional diversity.

Background and aim: In the present study, we focus on the relationship between state authenticity – the experience of being true to oneself in a particular moment – and microdosing – a practice that implies repeatedly ingesting very small doses of psychedelics that do not reach the threshold for perceptual alterations. We propose that microdosing could increase state authenticity through influencing people's mood and the number and satisfaction with daily activities. Methods: We used self-assessments of state authenticity collected from 18 microdosers in the Netherlands across the period of 1 month for a total of 192 observations. Results: We found that on the microdosing day and the day thereafter, state authenticity was significantly higher. Furthermore, the number of activities and the satisfaction with them were higher on the day when participants microdosed, while the following day only the number of activities was higher. Both the number or activities and the satisfaction with them were positively related to state authenticity. Conclusion: We propose that feeling and behaving authentically could have a central role in explaining the positive effects of microdosing on health and wellbeing that are reported by current research.

Background and aim: Subjective and anecdotal accounts link ingestion of psychedelic microdoses, quantities small enough to retain perceptual clarity, to enhanced cognitive function and performance. In this study we review current evidence, test the link between domains of cognitive function and microdosing psychedelics and evaluate a remote testing approach for cognitive function. Methods: In an observational within-subjects design, we repeatedly assessed 17 participants during their microdosing regimen using the CNSVS neurocognitive battery in a naturalistic setting. Results: We found that neither the day of microdosing, nor the day after microdosing are significantly linked to enhanced or diminished performance on processing speed, sustained attention, inhibitory control, set shifting, working memory, visual memory and verbal memory. Conclusion: Microdosing psychedelics may act on psychological rather than neurocognitive pathways to induce a subjective feeling of performance enhancement. The use of remote cognitive batteries might benefit longitudinal cross-cultural studies by reducing participant burden