Treatment efficacy of imagery rescripting and imaginal exposure for nightmares Evidence from a randomized wait-list controlled trial

Introduction: About 2-5% of the general population is suffering from nightmare disorder. Nightmares are associated with several negative consequences but can be effectively treated with cognitive-behavioral therapies. Imagery rescripting (IR) and imaginal exposure (IE) are commonly identified as active treatment ingredients of psychological nightmare treatments. However, it remains unclear which specific therapeutic elements are responsible for the beneficial effects on nightmare symptoms. With this randomized controlled trial, we aimed to investigate the isolated therapeutic efficacy of IR and IE for nightmares.

Materials and methods: In this trial we randomized 104 patients with a primary DSM-5 diagnosis of nightmare disorder into an IR, IE, or wait-list control group. In the intervention conditions all participants received three weekly 60 minutes individual treatment sessions. The treatment conditions only consisted of IR or IE and did not comprise of treatment elements such as extensive psycho-education, relaxation and safe-place exercises, or nightmare journals.

Results: Post-test results showed that compared to WL, both interventions effectively reduced nightmare frequency and distress, as well as other associated symptoms such as the number of nights with nightmares, insomnia complaints, and dysfunctional nightmare beliefs. These results were sustained at three- and six-month follow-up.

Conclusions: Given that the observed effects of IR and IE were comparable to those observed in meta-analyses for other psychological nightmare treatments, we conclude that IR and IE both seem to be active treatment components in nightmare therapies. Future research is needed to examine the potential superiority or equivalence of IR and IE in the treatment of nightmares. In a similar vein, future studies should investigate the potential beneficial effects of combining IR and IE.