Context: IRT is a treatment for chronic nightmares which consists of evoking the nightmares, modifying them by positively rewriting them, then repeating the new positive version. While its effectiveness has been demonstrated, the cognitive mechanisms which underpin the therapeutic effect remain little understood. Visual mental imagery capacities, the mastery, positive imagery incorporation and the number of rehearsals may all play a role. But the most debated component is exposure. The process of exposure is influenced by the time delay between memory recuperation of the anxiety-inducing stimulus and the habituation phase, this period of lability has been called the reconsolidation window, which lasts for less than an hour. If IRT is influenced by this factor, i.e. if the time delay between evoking the nightmare and rescripting it influences the outcomes, then one of its components is surely exposure.

Objectives: the aim of this study is to assess whether exposure is a therapeutic component of IRT.

Methods: Forty-eight patients suffering from nightmares with or without Post-Traumatic Stress Disorder (PTSD) were included in this randomized controlled trial (RCT). Patients were randomly allocated to one of two groups to follow a remote IRT programme, which required them to positively rescript their dreams, either 1) immediately after evoking the nightmare (during the period of memory reconsolidation), or 2) with a time delay of at least one hour after the nightmare recall. The impact of the treatment on the frequency of nightmares, their emotional content, sleep quality and symptoms of PTSD was assessed using questionnaires and a dream diary. The covariations of other therapeutic components and clinical improvements were also measured.

Results: IRT is effective in reducing nightmares, sleep disturbances and other symptoms of PTSD. No difference was observed between the two experimental groups.

Conclusion: Exposure does not seem to be a critical factor. Other components, and in particular the feeling of control over dreams or positive imagery incorporation, may play a role, the investigation of which would require precise analysis of the dynamics of therapeutic effects.


  • Randomized Controlled Trial: component analyses
  • Pre-treatment - Post-treatment - Follow-up 6 month
  • 4 sessions of individual CBT


  • Funding: Fondation VINCI autoroute
  • Funding Applicant: Benjamin Putois
  • Institution: Association nationale pour la promotion de la connaissance sur le sommeil
  • Institutional partners: INSERM, Association ABC Psychotrauma.
  • Web site: http://imaginever.org


  • Research Coordinator, Psychologist-Psychotherapist, Statistician: Benjamin Putois
  • Responsible physician: Dr Hélène Bastuji, Praticien Hospitalier en Neurologie, Médecin Coordonnateur de la Fédération des Unités d’Exploration et de Traitement des Troubles du Sommeil des HCL. Unité d’hypnologie, Hôpital Neurologique, 59, bd Pinel 69677 Bron
  • Neurologist Partner: Dr Laure Peter-Derex, Médecin Neurologue, CHU de LYON, Service de Neurologie-sommeil, Hôpital Lyon Sud, Pierre Bénite.
  • Physician Partner: Dr Wissam El-Hage, Médecin psychiatre, CHU de Tours, Clinique Psychiatrique Universitaire, Tours, France.
  • Physician Partner: Claire Braboszcz, School of Psychology, University of Plymouth, United Kingdom
  • Scientific Translator: Wendy Leslie, Lyon 1 University.

Publications & Communications

  • Putois, B. (2020). Manuel de guérison des cauchemars. Paris: Les arènes.
    Putois, B., Leslie, W. Asfeld, C., Sierro, C., Higgins, S., Ruby, P. (2020) Methodological recommendations to control for factors influencing dream and nightmare recall in clinical and experimental studies of dreaming. Frontiers neurology, 11, 724.
    Sierro, C., Leslie, W., & Putois, B. (2020). Long-term effects of treatment for chronic nightmares: is imagery rehearsal therapy robust in the COVID-19 pandemic? Journal of Clinical Sleep Medicine.
  • Putois B., Peter-Derex, L., Leslie, W., Braboszcz, C., El Hage, W., & Bastuji, H. (2019). Internet-Based Intervention for Posttraumatic Stress Disorder: Using Remote Imagery Rehearsal Therapy to Treat Nightmares. Psychother Psychosom, 8: 1-2.
  • Putois, B. (2017). Sommeil et traumatisme : des insomnies et des cauchemars. in Canini, F. & Garcia, R. ABC des psychotraumas.
  • Putois, B. & Peter-Derex, L. (2016). Intérêt de l’Imagery Rehaersal Therapy dans les cauchemars associés aux pathologies neurologiques du sommeil. Congrès du sommeil, Société Française de Recherche en Médecine du Sommeil (France), communication affichée.