Mediators, mechanisms and moderators of action for EMDR therapy: A review of multiplex effects in modes of bilateral stimulation

In "Mediators and mechanisms of change in psychotherapy research" Kazdin states unequivocally (2007, p. 1) that "after decades of psychotherapy research, we cannot provide an evidence-based explanation for how or why even our most well studied interventions produce change..." Despite more than 30 research and review papers and chapters exploring its mechanisms of action, the same conclusion applies to EMDR therapy. To forge a comprehensive framework for understanding EMDR therapy treatment effects, it is essential first to carefully conceptualize differences between mediators, mechanisms and moderators of change in psychotherapy in general (Kazdan, 2007) and in EMDR therapy in particular. Following Kazdan's guidance (p. 21) – "Looking for one explanation or mechanism for one group, one therapy, or one outcome may yield little" – six primary categories of hypothesized mechanisms of action for EMDR therapy have been examined in careful research or are amenable to direct study. These six distinct hypothesized mechanisms of action appear to provide diverse multiplex effects, sometimes converging and sometimes diverging, leading to various outcomes in different clinical contexts and in different EMDR procedures. This presentation will review the existing laboratory and controlled clinical published research on the specific effects of bilateral eye movements, bilateral tones and bilateral kinesthetic stimulation as used in EMDR therapy to evaluate how these various mediators contribute to EMDR treatment effects in disparate clinical contexts. This analysis will lead to potential implications in EMDR therapy for moderators such as degree of structural dissociation and for mediators including selection of modes of bilateral stimulation.

Conference

English

Andrew Leeds

Leeds, A. (2016, June). Mediators, mechanisms and moderators of action for EMDR therapy: A review of multiplex effects in modes of bilateral stimulation. In Neurobiology (Derek Farrell, Chair). Presentation at the at the 17th EMDR Europe Association Conference, The Hague