More preparation time was associated with larger effects in psychedelic therapy trials
Preparation time tracked symptom effects across studies, but the analysis cannot show that adding hours improves outcomes.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Trials with more preparation therapy tended to show larger reductions in depressive symptoms with psychedelic-assisted therapy relative to controls. Because preparation time was compared across studies, this association does not show that adding hours would improve outcomes. Integration hours showed no statistically significant association; the total-session-count result remains unresolved because the reported statistics conflict.
Most studies had high risk of bias, largely because blinding was ineffective. The reported session-count estimate, confidence interval and significance test conflict, so that result needs full-text or corrected-source clarification.
What researchers found
Preparation hours and depressive symptom effects
Across trials, each additional preparation hour was linked to a shift of -0.13 standard deviations in symptom effects, meaning a larger reduction with psychedelic-assisted therapy versus controls. All available posttreatment assessments were included; follow-up lengths were unreported.
Preparation and integration
Preparation sessions preceded psychedelic administration; integration sessions followed it. Researchers examined hours, session counts and overall therapy duration, so the analysis concerned therapy quantity rather than therapeutic quality.
Understanding the effect scale
Standard-deviation units express symptom differences relative to score variability. Overall, psychedelic-assisted therapy favored symptom reduction versus controls, with smaller effects at longer follow-up. The preparation association cannot establish the improvement caused by another hour.
The original publication
Psychological Therapy Quantity and Depressive Symptom Reduction in Psychedelic-Assisted Therapy: A Systematic Review and Meta-Analysis.
Florineth GA, Klima I, Boeker AL et al.
JAMA Netw Open · 2026
- PubMed ID
- 41563753
- Record checked
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