Different lens or different picture? Comparing methods of defining dramatic change in psychotherapy

Differing methodologies that identify dramatic change in psychotherapy have been thought to be capturing similar phenomena. We compared three methods-percentage improvement-50% (PI-50), rapid response (RR), and sudden gains (SG)-to identify similarities and differences between these approaches.

Using a large database (n = 11,764) from a western university counseling center, we examined client characteristics (including initial severity and number of sessions in a course of treatment) and treatment outcomes (including overall change and meeting clinically significant criteria) using the Outcome Questionnaire-45.

Approximately 47% of clients (n = 5516) met criteria for one or more of the dramatic change definitions examined. Only 498 clients (3.7%) met criteria for all three methods, while 1349 (11.5%) met criteria for only one; RR identified the most clients (41.9%) and SG identified the fewest (4.9%). All definitions were associated with higher rates of clinically significant change at termination. Compared to those who recovered gradually, dramatic changers showed higher initial severity and more overall change. RR showed fewer sessions and PI-50 and SG showed more sessions than those who recovered gradually.

Given these differences, consensus needs to be reached in the literature regarding the definition of dramatic change. We call for further theory development and research to help formulate a definition that can be simply applied and that more fully and parsimoniously captures the phenomenon of dramatic change.