Long-Term Psychodynamic Psychotherapy for Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

This pre-registered systematic review and meta-analysis (PROSPERO CRD42023490547) evaluated the effectiveness of long-term psychodynamic psychotherapy (LTPP) in reducing depressive symptoms using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework and updated empirically supported treatment (EST) criteria. MEDLINE, PsycINFO, Embase, and the Cochrane Central Register of Controlled Trials were searched through January 16, 2025. Sixteen randomized controlled trials involving 1992 participants met inclusion criteria (LTPP ≥9 months, ≥30 sessions), encompassing varied populations, psychodynamic modalities, and comparator conditions. Effects were pooled using two- or three-level random-effects models. Risk of bias was assessed using Cochrane RoB 2. At treatment completion, LTPP showed significant reductions in depressive symptoms compared to all comparators (SMD = 0.34, 95% CI [0.20, 0.47]) and to active treatments specifically (SMD = 0.27, 95% CI [0.1, 0.45]). Effects were generally sustained at follow-up. Subgroup analyses revealed larger effects when LTPP was compared to active controls (SMD = 0.61), but with greater heterogeneity and very low certainty of evidence. GRADE assessments indicated high-certainty evidence for depressive symptom outcomes in the all-trials condition and moderate-certainty evidence in comparisons with active treatments. According to updated EST criteria, these findings support a Strong recommendation for LTPP in reducing depressive symptoms. However, limited evidence on functional outcomes, economic impact, and long-term maintenance precluded a Very Strong recommendation. Evidence from comparisons with active controls was of very-low certainty, supporting only a Weak recommendation. Risk of bias was a concern in most studies. Moderator analyses were prevented by small study numbers. Future individual patient data meta-analyses are needed to identify predictors of treatment response and to establish which subgroups of patients with depression are most suitable candidates for LTPP. Funding: Royal Australian and New Zealand College of Psychiatrists.