EDTs have solid empirical validation

Experiential Dynamic Therapies (EDTs) have strong empirical support. Randomized Controlled Trials (RCTs), considered the gold standard for treatment evaluation have been conducted for a wide range of depressive, anxiety, somatic (physical) symptom, and personality disorders.

Meta-analysis of EDT RCTs

In 2016, Peter Lilliengren and colleagues published a meta-analysis of 28 RTCs published between 1978 and 2014, with a total of 1,782 patients, showing that EDT performance was comparable with other empirically-validated treatments. In 2025, Lilliengren and co-authors repeated their analysis; by including RCTs published up until 2024, they were able to include 57 RTCs with a total of 4,330 patients. They concluded that “findings support EDTs as efficacious transdiagnostic interventions for emotional disorders, with sustained benefits over time.” In fact, there was even statistically significant evidence suggesting that EDTs have potential modest advantage at long-term follow-up compared to other therapies (active controls).

Lilliengren, P., Mechler, J., Lindqvist, K., Maroti, D. and Johansson, R. (2025), The Efficacy of Experiential Dynamic Therapies: A 10-Year Systematic Review and Meta-Analysis Update. Clin Psychol Psychother, 32: e70086. https://doi.org/10.1002/cpp.70086

EDT research summaries

The EDT research base is growing so rapidly that it can be hard to follow. Allan Abbass and John Moulder-Brown compiled an “ISTDP Research Overview,” a comprehensive collection of research on ISTDP and some related therapies as of July 2025, which is available for download on Allan Abbass’ website.

IEDTA Research Committee

The IEDTA Research Committee aspires to bridge the gap between research and practice by communicating about past and current EDT research on this website, on the IEDTA’s email discussion group, and at IEDTA conferences. We want to get the word out about the evidence base of EDT! If you have any suggestions, questions or research ideas, please email research@iedta.net, and please consider joining our committee!