Classical psychedelic microdosing, mood, and cognitive function: An umbrella review with narrative synthesis
Journal of Psychopharmacology June 28, 2026 Yiğit Özaydın, Buket Canlan Ozaydin
An umbrella review of systematic reviews and meta-analyses on psychedelic microdosing (repeated low doses of LSD or psilocybin) for mood and cognitive effects found that the only statistically significant pooled result was a small decrease in cognitive control, contrary to popular claims of enhancement. Self-reported mood benefits were largely not replicated under placebo-controlled conditions, suggesting expectancy effects. Short-term tolerability was acceptable, but cardiovascular signals and long-term risks remain uncharacterized. The evidence base is limited by high overlap among primary studies and methodological heterogeneity.