The role of simulation in imagery rescripting for post-traumatic stress disorder: a single case series

Imagery rescripting (ImRs) is an experiential therapy technique used to change the content and meaning of intrusive imagery in post-traumatic stress disorder (PTSD) by imagining alternative endings to traumatic events. There is growing evidence that ImRs is an effective treatment for PTSD; however, little is known about how it brings about change.

This study aimed to explore the role of mental simulation as a candidate mechanism of action in ImRs, and, specifically, whether well-simulated imagery rescripts are associated with greater change in symptom severity during ImRs.

Using a single-case experimental design, seven participants receiving cognitive therapy for PTSD were assessed before, during and after sessions of imagery rescripting for one intrusive image. Participants completed continuous symptom severity measures. Sessions were recorded, then coded for goodness of simulation (GOS) as well as additional factors (e.g. rescript believability, vividness).

Participants were divided into high- and low-responders and coding was compared across groups. Correlational analyses were supported by descriptive analysis of individual sessions. High-responders' rescripts tended to be rated as well-simulated compared with those of low-responders. Specific factors (e.g. intensity of thoughts/emotions related to original and new imagery elements, level of cognitive and emotional shift and belief in the resultant rescript) were also associated with reductions in symptom severity.

There was tentative evidence that well-simulated rescripted images tended to be associated with greater reductions in symptom severity of the target image. Clinical implications and avenues for further research are discussed.