Is longer-term psychodynamic psychotherapy more effective than shorter-term therapies? Review and critique of the evidence.

Background: In 2008, Leichsenring and Rabung performed a meta-analysis of 8 studies of longer-term psychodynamic psychotherapy (LTPP). The work was published in the Journal of the American Medical Association (vol. 300, pp 1551-1565), and they concluded that LTPP was more effective than shorter-term therapies.

Method: Given that such claims have the potential to influence treatment decisions and policies, we re-examined the meta-analysis and the 8 studies.

Results: We found a miscalculation of the effect sizes used to make key comparisons. Claims for the effectiveness of LTPP depended on a set of small, underpowered studies that were highly heterogeneous in terms of patients treated, interventions, comparison-control groups, and outcomes. LTPP was compared to 12 types of comparison-controls, including control groups that did not involve any psychotherapy, short-term psychodynamic psychotherapy, and unvalidated treatments. Additionally, the studies failed to protect against threats to bias, and had poor internal validity.

Conclusion: Overall, we found no evidence to support claims of superiority of LTPP over shorter-term methods of psychotherapy.