A Meta-analysis of Imagery Rehearsal for Post-trauma Nightmares: Effects on Nightmare Frequency, Sleep Quality, and Posttraumatic Stress

A meta-analysis of 13 clinical trials found that imagery rehearsal therapy produces large reductions in nightmare frequency, sleep disturbance, and PTSD symptoms, with benefits lasting 6 to 12 months. Adding cognitive behavioral therapy for insomnia to imagery rehearsal further improved sleep quality but did not enhance PTSD or nightmare outcomes. Effect sizes were small in the only study that used an active-treatment control group.

Study at a glance

Abstract

This meta-analysis evaluates the efficacy of imagery rehearsal as a treatment for nightmares, general sleep disturbance, and symptoms of post-traumatic stress. Bibliographic databases and cited references were searched to identify clinical trials of imagery rehearsal in individuals with post-trauma nightmares. Thirteen studies met inclusion criteria and reported sleep and post-traumatic stress outcomes in sufficient detail to calculate effect sizes. Results indicate that imagery rehearsal had large effects on nightmare frequency, sleep quality, and PTSD symptoms. These effects were sustained through 6 to 12 month follow-up. Furthermore, interventions that included both imagery rehearsal and cognitive behavioral therapy for insomnia resulted in greater treatment-related improvement in sleep quality than imagery rehearsal alone. Combined treatment did not improve outcomes for PTSD or nightmares. Notably, effect sizes were small in the single study that included an active-treatment control condition. Future research should identify necessary and sufficient components of interventions for trauma-related sleep disturbance and post-traumatic stress (e.g., exposure, cognitive reappraisal, circadian regulation).