Psychological Therapy Quantity and Depressive Symptom Reduction in Psychedelic-Assisted Therapy: A Systematic Review...

Area of Science:

• Psychiatry and Behavioral Sciences
• Clinical Psychology
• Psychopharmacology

Background:

• Psychedelic-assisted therapy (PAT) shows promise for treating depressive symptoms.
• The role of concomitant psychological therapy in PAT outcomes requires further investigation.
• Quantitative evidence linking therapy quantity to treatment efficacy is limited.

Purpose of the Study:

• To evaluate the association between the quantity of psychological therapy and symptom reduction in PAT for depression.
• To synthesize quantitative evidence from controlled clinical trials on PAT for depressive symptoms.

Main Methods:

• Systematic review and meta-analysis of controlled clinical trials.
• Searched PubMed, PsycINFO, and Scopus databases.
• Included trials using classic serotonergic psychedelics for adults with depressive symptoms.
• Metaregression analyses assessed the impact of therapy quantity (hours, sessions, duration) on outcomes.

Main Results:

• PAT demonstrated a large overall effect size in reducing depressive symptoms (Hedges g = -0.84).
• Increased hours of preparation therapy were significantly associated with greater symptom reduction (β = -0.13, P = 0.04).
• No significant associations were found for integration therapy hours or total session count.

Conclusions:

• Greater quantity of preparation therapy in PAT is linked to improved depressive symptom reduction.
• These findings suggest a crucial role for preparation in optimizing PAT outcomes.
• Further research is needed to clarify this association and optimize therapeutic components in psychedelic interventions.