Evaluating Mechanisms: Mapping Weekly Dynamics between Experiential Avoidance and SAD Symptoms

Widely-used, empirically-supported treatments focus on reducing experiential avoidance (EA) as a mechanism of social anxiety disorder (SAD) symptom change. However, little is known about how EA and SAD symptoms bidirectionally interrelate from session to session, or throughout the course of an intervention—a gap that raises significant theoretical and clinical questions about the mechanistic role of EA. Participants (N = 78) with elevated EA and SAD symptoms completed a 3-session pilot intervention (Approach-Avoidance Task training plus psychoeducation) designed to target EA. Bivariate latent change score modeling was then used to map the bidirectional, temporal interrelationships between EA and SAD symptoms from session to session. Analyses accounted for the overall trajectory of change in both variables (i.e., EA and SAD) and both variables’ preceding measurement. Findings suggested that changes in SAD symptoms preceded and predicted changes in EA from session to session. Contrary to hypotheses, this effect was not bidirectional, as changes in EA did not precede and predict changes in SAD symptoms from session to session. The use of a relatively small analogue sample limit the external validity of the present findings. Nevertheless, these novel findings advance our understanding of the dynamic interrelationships between EA and SAD symptoms throughout treatment. Moreover, given that many leading treatments target EA, this study highlights a need for future work to continue evaluating whether EA is indeed a mechanism of SAD symptom change.