A Series of Meta-Analytic Tests of the Efficacy of Long-Term Psychoanalytic Psychotherapy

Recent meta-analyses come to conflicting conclusions about the efficacy of long-term psychoanalytic psychotherapy (LTPP). Our first goal was to reproduce the most recent meta-analysis by Leichsenring, Abbass, Luyten, Hilsenroth, and Rabung (2013) who found evidence for the efficacy of LTPP in the treatment of complex mental disorders. Our replicated effect sizes were in general smaller. Second, we conducted an updated meta-analysis of randomized controlled trials comparing LTPP (lasting for at least one year and 40 sessions) to less intensive forms of psychotherapy in the treatment of complex mental disorders. We focused on a transparent research process according to open science standards and applied a series of cutting-edge meta-analytic procedures to test and control for publication bias. Our updated meta-analysis comprising 191 effect sizes from 14 eligible studies revealed small, statistically significant effect sizes at post-treatment for the outcome domains psychiatric symptoms, target problems, social functioning and overall effectiveness (Hedges’ g ranging between 0.24 and 0.35). The effect size for the domain personality functioning (0.24) was marginally significant. No signs for publication bias could be detected. In light of a heterogeneous study set and some methodological shortcomings in the primary studies, these results should be interpreted cautiously. In conclusion, we found some, yet weak evidence that LTPP was superior to less intensive forms of psychotherapy in the treatment of complex mental disorders. Notably, two primary studies applying the most advanced psychoanalytic psychotherapy and research methods revealed a medium overall effect (0.5 and 0.6) encouraging to conduct further research.