New study finds no evidence in support of LTPP's superiority over shorter-term methods of psychotherapy

This paper criticizes the methodology of a meta-analysis and 8 studies published in the JAMA last year which indicated that longer term psychodynamic psychotherapy (LTPP) was more effective than short therapies. The investigators found a miscalculation of the effect sizes used to make key comparisons and found no evidence to support claims of superiority of LTPP over shorter-term methods of psychotherapy.

In a meta-analysis published in the JAMA last year it was concluded that longer term psychodynamic psychotherapy (LTPP) was more effective than short therapies.

Now a group of psychotherapy researchers including Aaron Beck, the father of cognitive therapy, criticizes the methodology of that paper. Their criticism is published in the current issue of Psychotherapy and Psychosomatics.

The Authors re-examined the meta-analysis and the 8 studies and 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.

Overall, at the end of the investigation the Authors found no evidence to support claims of superiority of LTPP over shorter-term methods of psychotherapy.