The Abuse Liability of Classic Psychedelics: A Methodological Critique and Assessment of the Quality of Evidence of Recent Studies

Abstract Purpose of Review We highlight key findings and methodological issues from recent research on the abuse liability of classic psychedelics, utilizing a GRADE to assess the quality of the evidence. Recent Findings Studies using various designs suggest that classic psychedelics (e.g., psilocybin, LSD) have low abuse potential and less dependence liability than other drugs. However, public health risks may be underestimated, and current findings should be interpreted with caution due to several methodological issues. Summary Existing work suggests that classic psychedelics have limited abuse liability, but evidence is of low quality. Researcher allegiance and publication bias are general concerns. Clinical trials are subject to functional unblinding and expectancy effects. Other studies primarily rely on cross-sectional, self-reported data, have limited demographic diversity, rarely measure changing consumption patterns or disaggregate various psychedelics, and use varying definitions of abuse. Further research should address these issues and clarify abuse liability of individual psychedelics.