Over the past 70 years, there has been an abundance of research indicating that psychotherapy works. However, the question of how therapy works has remained elusive. In fact, a therapist can follow a logical, systematic application of a specific therapy approach, but will still only have a vague sense of what is actually happening in the process over time and how that might relate to outcomes. Given the wide range of effective psychotherapy approaches that produce similar, positive outcomes, it is logical to conclude that there is something happening in the therapy process overtime that is more impactful than the approach itself. The purpose of this literature review is to view the empirical results on psychotherapy process through the lens of nonlinear dynamical systems theory in order to derive a more parsimonious set of processes that may be at work in facilitating positive treatment outcomes. Nonlinear dynamical systems (NDS) theory is a broad approach to science focusing on the potentially complex interactions of multivariate systems unfolding over time. NDS is aimed at understanding complex patterns. Two factors make NDS especially appealing for understanding psychotherapy process: 1) Linear science has been unable identify a set of independent predictors of outcome; 2) The targets of change in psychotherapy are themselves complex patterns of thought thought, behavior, emotion, and social relationships, each of which is interactive with the other and changing over time. The conclusions drawn from the existing research on psychotherapy process will be synthesized and used to form hypotheses that can be empirically tested using analogue and clinical research designs.
Harding, Mary, "A Nonlinear Dynamical Systems Lens on Psychotherapy Process" (2020). Student Scholar Symposium Abstracts and Posters. 386.