Psilocybin microdosers demonstrate greater observed improvements in mood and mental

Microdosers were more likely than non-microdosers to be older (x² (2, N = 1133) = 22.13, p < 0.01), of White ethnicity (x² (1, N = 1133) = 4.62, p = 0.03) and to report full-time employment (x² (3, N = 1122) = 11.83, p < 0.01); groups were equivalent in all other demographic domains (all x²’s < 6.03, all p’s 0.05; see Table 1). Comparisons among microdosers of dosage and past-month microdose days found no differences across Age (days: x² (2, N = 953) = 3.37, p = 0.19; dose: x² (2, N = 953) = 3.31, p = 0.19) and Mental Health Concerns (days: x² (2, N = 931) = 0.71, p = 0.70; dose: x² (2, N = 931) = 0.21, p = 0.90).

Preliminary analyses identified expected differences according to Age; the under 55 group demonstrated superior performance to the 55 + group on all cognitive tasks; for Tap Test (Mean = 70.48 (33.18) versus 52.60 (29.99); t (1, 863) = 5.05, p < 0.01); for PASAT (Mean = 33.67(14.21) versus 30.37 (12.92) t (1, 772) = 2.08, p < 0.05) and Spatial Span (Mean = 236.25 (51.02) versus 176.88 (58.80); t (1, 943) = 11.00, p < 0.01). Baseline differences by Age were identified for negative mood (mean = 46.89 (16.13) versus 40.64 (16.06); t (1, 1048) = 3.96, p < 0.01) but not positive mood (mean = 55% (16) versus 55.03% (15.01); t (1, 1048) = − 0.018, p = 0.99). As expected, participants who reported Mental Health Concerns evinced higher scores on all three DASS subscales: Depression (mean = 10.44 (9.72) versus 18.92 (12); t (1, 1010) = − 11.81, p < 0.01); Anxiety (mean = 6.38 (6.36) versus 11.38 (8.74); t (1, 1010) = 10.09, p < 0.01) and Stress (mean = 13.84 (9.1) versus 20.04 (9.8); t (1, 1010) = 9.61, p < 0.01). Gender analysis revealed no main effect of gender across time in any of the DASS domains (All F < 1.6, p 0.20).

Depression, anxiety, stress

Comparisons of microdosers to non-microdosers in change from baseline to month-1 (Microdose*time) indicated greater improvements among microdosers across the DASS domains of Depression (F (1, 1019) = 17.91, b = 0.12, p < 0.01), Anxiety (F (1, 1017) = 18.33, b = 0.08, p < 0.01), and Stress (F (1, 1016) = 15.60, b = 0.08, p < 0.01) (Fig. 1; Table 2). These effects remained consistent following the removal of 124, 82, and 75 outliers within Depression, Anxiety, and Stress domains respectively for scores exceeding 2 standard deviations from the mean (all Microdose*time F 7.99 p < 0.01), and in parallel analyses restricted to the 594 participants who did not report microdosing prior to baseline (all Microdose*time F 4.17, p < 0.05). We identified a Microdose*Gender*Time interaction such that the effect of microdosing over time was found to be moderated by gender in DASS depression. Specifically, microdose-related reductions in depression were stronger among females than among males (F (1, 1016) = 6.61, b = 0.17, p = 0.01). No Microdose* Gender*Time interaction was identified for DASS anxiety (F (1, 1024) = 1.14, b = 0.46, p = 0.29) or DASS stress (F (1, 1023) = 0.90, b = 0.05, p = 0.34).

The interactions between Mental Health Concerns and Microdose groups were not significant for any of the domains (all Microdose*Mental Health Concerns*Time…