Treating nightmares with imagery interventions

The proposed study aims at investigating the effectivity of two CBT-based treatments for nightmares (i.e., imagery rescripting and imaginal exposure), as well as possible working mechanisms underlying these therapeutic techniques.

It is hypothesized that imagery rescripting and imaginal exposure therapy are both effective in the treatment of nightmare disorder.

Whereas it is expected that the two therapies will both be effective in the treatment of nightmares, it might be possible that the therapies work through different mechanisms. The current study aims at exploring the working mechanisms of the two therapies by assessing the effects of several proposed mediators (see 'secondary outcome measures') of the treatment effect (see 'primary outcome measures').

(1) Pre-assessment ; (2, 3, 4) treatment sessions; (5) Post-assessment ; (6) 3-months follow-up ; (7) 6-months follow-up

Both active interventions will be delivered by trained and experienced therapists.

Imagery rescripting (IR) therapy: participants will receive an adapted 3-session intervention of the original IR protocol by Arntz en Weertman (1999). Here, the script of a nightmare is actively changed in the imagination of the participant, after the original nightmare has been reactivated.

Imaginal exposure (IE) therapy: participants will receive 3 sessions of a standard IE intervention (Foa & Rothbaum, 1989). Here, the nightmare is reactivated and subsequently re-lived in the participants’ imagination, until the emotions accompanied by the nightmare become tolerable.

Wait-list control condition: 5 weeks. Note that after the waiting period, participants will receive either one of the active treatments (by randomization). Here, treatment will be delivered by unexperienced therapists (e.g., students). Primary and secondary outcome measures (but no mediators of the treatment effect) will be assessed at time points 1 and 5 to investigate whether the treatment effects found in the main study (i.e., treatment delivered by experienced therapists) can be replicated with a group of unexperienced therapists.