In-session factors appear to be the strongest predictors of antidepressant improvement in psychedelic-assisted therapy. Emotional breakthrough, mystical or unitive qualities, and ego dissolution paired with insight or reappraisal were most often linked with larger and more durable symptom reductions. Anxiety-dominant or dysphoric states tended to coincide with smaller gains, even when overall intensity was high.
Set and setting also mattered. A stronger therapeutic alliance and music that felt personally resonant were associated with both the emergence of therapeutically salient acute experiences and downstream clinical benefit, suggesting that context can shape outcomes.
Baseline traits were less consistent. Demographics rarely predicted response; PTSD comorbidity sometimes related to weaker courses; and extensive prior psychedelic exposure was occasionally tied to smaller incremental improvement. Biological signals linked better outcomes with markers of greater neural flexibility and plasticity, alongside peripheral changes related to neurotrophic, inflammatory, and HPA-axis processes.
These patterns come from a scoping review across varied studies, not a single definitive meta-estimate, so they should be considered provisional; see a recent scoping review on predictors in psychedelic therapy for depression: PubMed. In short, what happens during the session and how the context is tuned seem to matter most.