Supplementary Material for: Emotional changes during Imagery Rescripting of aversive social memories in Social Anxiety Disorder: a randomized controlled trial

Introduction: Imagery Rescripting (ImRs) is a psychotherapeutic intervention targeting aversive memories. During the three-phase intervention, patients re-experience their aversive memory (phase 1), observe the scene from their adult perspective and intervene to help their former selves (phase 2), and re-experience it again with the positive changes (phase 3). Previous studies have rarely investigated emotional and regulatory processes taking place during the intervention. Objective: This randomized-controlled trial investigated self-reported affective and physiological responses during ImRs. Methods: Seventy-seven patients with Social Anxiety Disorder (SAD) were randomly assigned to a single session ImRs or a control intervention (recall and discussion of the memory) targeting an aversive social memory. Heart rate (HR) and heart rate variability (HRV) were assessed during and post-hoc ratings of positive and negative feelings after baseline and the intervention phases. Results: Relative to the control intervention, ImRs resulted in an initial increase in negative feelings from baseline to phase 1 and a following larger (phase 1 to phase 2) and more stable (phase 2 to phase 3) decrease in negative feelings/increase in positive feelings. On the physiological level, during ImRs compared to the control intervention, mean HR was significantly higher during phase 1 and HRV during phase 3, each compared to baseline. Conclusions: These results provide further information about the specific sequence of emotional responses on different response levels during ImRs, being consistent with known theories of emotional processing and supposed mechanisms of ImRs.