Adults who microdose psychedelics report health related motivations and lower levels of anxiety and depression compared to non-microdosers

Rootman and colleagues situate microdosing—regular use of sub-sensorium amounts of psychedelics—within a long history of psychedelic use by Indigenous peoples and recent resurgence in non‑Indigenous contexts. The introduction summarises how most prior scientific attention has focused on full psychedelic doses, whereas microdosing (commonly with psilocybin or LSD) is reported anecdotally to support mood, cognition and general well‑being. The authors note heterogeneous microdosing practices (dose, frequency) and the growing but understudied phenomenon of "stacking", the co‑use of non‑psychedelic substances such as Lion's Mane, niacin or chocolate with microdoses. They highlight a lack of rigorous evidence on microdosing’s mental health effects, on whether reported differences vary by prior mental health history, and on how motives and practices differ across subgroups. The present study reports baseline data from the Microdose.me project, an ongoing longitudinal study designed to characterise microdosing practices, motivations and mental health in a large international sample. The investigators aimed to (1) describe microdosing practices including stacking, (2) compare microdosers and non‑microdosers on depression, anxiety and stress symptoms—particularly among those reporting mental health concerns—and (3) examine whether practices and motives vary by gender and mental health status. The authors present these baseline cross‑sectional findings as a contribution to the limited empirical literature and as groundwork for future longitudinal and experimental work.

The study used a cross‑sectional baseline survey collected between November 2019 and July 2020 from self‑selected participants recruited through psychedelic‑related media and events. Participants were directed to the Microdose.me website and completed the study via the Quantified Citizen (QC) mobile application, which at the time was available only on Apple iOS devices; participation was anonymous and required respondents to be ≥18 years and able to complete an English survey, criteria that could not be independently verified due to anonymity. The baseline and supplementary questionnaires comprised up to 123 hierarchical items covering demographics, detailed microdosing practices (substance, dose, frequency, duration), stacking behaviours, other psychoactive substance use, lifetime use of large psychedelic doses, and motives for starting microdosing. After the baseline survey, participants were invited to complete the Depression, Anxiety and Stress Scale‑21 (DASS‑21), a 21‑item instrument with three 7‑item subscales assessing symptom severity over the past week. Classification into groups was based on the self‑report question "Are you currently engaged in a regular practice of microdosing?" Individuals who reported current regular microdosing were assigned to the microdoser group; the non‑microdoser group included those who had never microdosed and those with a history of microdosing who were not currently microdosing. Psilocybin and LSD microdose amounts were categorised into Low/Medium/High using thresholds derived from prior observational research: for LSD Low ≤ 10 µg, Medium 11–20 µg, High ≥ 21 µg; for psilocybin Low ≤ 0.1 g dried mushrooms, Medium 0.1–0.3 g, High ≥ 0.3 g. Participants could select multiple motives from a list of 18 options or provide free text. Statistical analyses used chi‑square tests to compare categorical variables (demographics, substance use, mental health conditions, microdosing characteristics, motives) and to compare LSD versus psilocybin microdosers. Adjusted residuals identified specific group differences and, to limit type I error from multiple comparisons, chi‑square tests used a p < 0.01 significance threshold. Univariate ANOVAs compared DASS‑21 Depression, Anxiety and Stress subscale scores between microdosers and non‑microdosers, restricted to participants who reported a mental health or substance use concern; supplementary 2×2 ANOVAs tested microdose status by gender. Additional analyses repeated DASS‑21 comparisons limited to participants with lifetime large‑dose psychedelic experience to account for potential confounding by prior high‑dose use.

The baseline survey was completed by 8,703 respondents from 84 countries; the largest proportions were from the USA (62.2%, n = 5,413), Canada (12.7%, n = 1,104), Australia and Great Britain (each 4.2%, n = 366). Current microdosing was reported by 4,050 respondents (46.5%), and 4,653 respondents (53.5%) were classified as non‑microdosers. Compared with non‑microdosers, microdosers tended to be older and more likely to live in urban areas. Overall, 29% of respondents endorsed a current psychological, mental health or addiction concern, most commonly anxiety, depression and PTSD/trauma‑related symptoms; less frequently endorsed conditions included bipolar disorder (2%), eating disorder (2%), opioid dependence (1%) and schizophrenia (< 1%). Substance use in the sample was high, with 78% (n = 6,760) reporting past‑year cannabis use. Microdosers were more likely than non‑microdosers to endorse any mental health or substance use concern (χ2 = 26.89, p < 0.01) and specifically showed higher endorsement of depression (χ2 = 6.95, p < 0.01), PTSD/trauma (χ2 = 8.92, p < 0.01) and tobacco dependence (χ2 = 3.88, p < 0.05). No significant group differences were observed for several other conditions including anxiety (χ2 = 3.19, p = 0.07), problematic cannabis use, problematic alcohol use, bipolar disorder or schizophrenia. Regarding other substances, microdosers were less likely to use alcohol frequently and more likely to abstain from alcohol and tobacco, while reporting more frequent cannabis use. Among respondents who completed the DASS‑21 and who reported a mental health or substance use concern, microdosers exhibited lower scores on the Depression, Anxiety and Stress subscales relative to non‑microdosers. Supplementary analyses restricted to participants with lifetime experience of large‑dose psilocybin or LSD (87% of the sample overall; 92% of microdosers vs 83% of non‑microdosers; χ2 = 161.13, p < 0.01) revealed the same pattern: microdosers demonstrated lower Depression, Anxiety and Stress scores (all F(1, 1433) > 6.00, p < 0.01). The authors note these between‑group effects are statistically significant but in the range typically characterised as small. Motivations for microdosing were led by Enhancing Mindfulness, followed by Improving Mood, Enhancing Creativity and Enhancing Learning. Participants with mental health concerns were more likely to endorse Reduce Anxiety, Decrease Substance Use and Improve Mood, whereas those without such concerns more often endorsed Enhance Learning. Gender differences in motives were observed: females more commonly reported Improve Mood and Decrease Anxiety; males more commonly reported Enhance Learning, Increase Sociability and Decrease Substance Use. In terms of practices, psilocybin was the dominant microdosing substance (over 85% of microdosers) versus ~11% for LSD. Psilocybin microdosers were more likely to report medium or high microdose amounts and a greater likelihood of daily or near‑daily use compared with LSD users. Psilocybin users were also more likely to report Decreasing Anxiety and Improving Sleep as motives, yet DASS‑21 scores did not differ between psilocybin and LSD microdosers. Stacking was common: more than half of microdosers combined their microdose with other substances, most frequently Lion's Mane (39%), niacin (18%) and chocolate (5%), with 16% reporting a combination of Lion's Mane and niacin. The extracted text ends mid‑description of comparisons between those who stacked and those who did not, so further details on stacker versus non‑stacker outcomes are not clearly reported here.

Rootman and colleagues interpret their findings as broadly consistent with prior cross‑sectional microdosing studies: psilocybin and LSD are the predominant microdosing agents, most users microdose 1–4 times per week, and motives centre on emotional well‑being and cognitive enhancement. Novel contributions include the large international sample, the inclusion of a demographically similar non‑microdosing comparison group, a detailed description of stacking practices, and the report that microdosers who endorse mental health concerns had lower symptom severity on the DASS‑21 Depression, Anxiety and Stress scales than non‑microdosers with comparable concerns. The authors emphasise that their cross‑sectional design prevents causal inference; lower symptom scores among microdosers may reflect benefits of microdosing, self‑selection of people who respond well to microdosing, or other confounding factors. They also note that the observed group differences were small and that findings rely on self‑report. The study identified behavioural correlates consistent with health‑oriented motives: microdosers were less likely to use alcohol or tobacco and more likely to report reducing problematic substance use as a motive, although they also reported more frequent cannabis use, which may reflect therapeutic rather than recreational intent. Safety considerations and limitations receive attention. The authors urge caution about generalising safety data from infrequent large‑dose psychedelic use to repeated microdosing, and flag a theoretical concern about cardiac valvulopathy via repeated 5‑HT2B receptor activation—an issue raised by analogy to other serotonergic drugs—while noting preclinical evidence to date has not confirmed psilocybin‑related valvulopathy. Key study limitations acknowledged include self‑selection and recruitment bias toward pro‑psychedelic communities, iOS‑only participation, inability to verify eligibility or prior microdosing practices, and limited granularity regarding stacking (for example, the form of Lion's Mane consumed). Strengths cited are the large sample size, the sizeable non‑microdosing comparison group, and the feasibility demonstrated for studying microdosing via an anonymous mobile application. The authors conclude that their results support further rigorous longitudinal and controlled trials to evaluate risks, benefits and best practices, and recommend distinguishing psilocybin and LSD in future research because of observed differences in dose, frequency, stacking and motives.

The authors conclude that, in this large international convenience sample, therapeutic and wellness motivations predominate among people who microdose psychedelics, and microdosers who report mental health concerns show lower self‑reported anxiety and depression than comparable non‑microdosers. They also document substantial diversity in microdosing practices—including dose, frequency and frequent co‑use of non‑psychedelic substances (stacking)—and call for further research to determine how these distinct practices affect cognition, mood and well‑being.