Nightmares and imagery rehearsal therapy

Imagery rehearsal therapy (IRT) is a cognitive-behavioural treatment for recurring nightmares. While awake, you write down a nightmare, change it in any way you choose, and rehearse the new version in your imagination for a few minutes each day. It is the only nightmare treatment that the American Academy of Sleep Medicine rates as recommended for adults¹.

This guide explains what counts as a nightmare problem, how IRT works, what the trials found, and where a self-guided attempt should stop and a clinician should take over. It is general information, not a diagnosis or a treatment plan.

When a bad dream becomes a nightmare problem

Almost everyone has an occasional nightmare. A problem is something narrower: frightening dreams that come often, wake you, stay vivid afterwards and make you dread going to sleep. Reviews put weekly nightmares at around 4 to 10 percent of the population⁵, and in a Finnish sample of nearly 70,000 adults, 3.5 percent of men and 4.8 percent of women reported frequent nightmares⁶. When the pattern is persistent and distressing, sleep medicine calls it nightmare disorder, which the AASM paper estimates affects about 4 percent of adults¹.

Nightmares often come with stress, trauma and other conditions, but they are not only a symptom. Krakow and Zadra argue that chronic nightmares can behave like a sleep disorder in their own right, a learned habit of the sleeping mind that keeps going after the original cause has faded². That idea is what makes a behavioural treatment plausible: if the nightmare is partly a habit, a new habit can be trained against it.

How imagery rehearsal therapy works

The method is simple to describe. In the version Krakow and Zadra set out for clinicians, it is taught in about four sessions of roughly two hours, and the core steps are few². You pick one nightmare, ideally not the worst one at first. You write it down. Then you change it. The change can be small or large: a door that opens, a different ending, a colour, a companion who was not there before. There is no right rewrite, and you do not have to make it happy, only different in a way you choose.

You then spend a few minutes each day, awake and calm, picturing the new version in as much detail as you can. You do not rehearse the original. Over days and weeks the rewritten dream is meant to compete with, and loosen, the old script. Clinicians usually add some practice with pleasant imagery first, so that the person learns that they can steer an image before working on a frightening one².

Why this would work is still debated. One account is that rehearsal changes the expectation the sleeping mind carries into the night; another is that it gives a person a sense of mastery over material that felt uncontrollable. Levin and Nielsen frame nightmares as a failure of the normal way dreaming processes fear, with distress about the nightmares making them worse⁵. IRT works on both ends: it reduces the nightmares and the dread of them.

What the evidence shows

The best-known trial randomised 168 women who had survived sexual assault and had chronic nightmares and posttraumatic stress symptoms. Those who received IRT in three sessions had clearly fewer nights with nightmares than those on a waiting list, and their PTSD symptoms also eased³. It was a strong result, though in one population with a waiting list as the comparison.

A meta-analysis of 19 randomised trials with 1,285 participants found that psychological treatments for nightmares, IRT among them, had a moderate effect overall, and that treatment delivered by a therapist did better than self-help⁴. The AASM position paper, which weighed the evidence for many options, rates IRT as recommended both for nightmares linked to PTSD and for nightmare disorder. It lists several other therapies and some medicines as options that may be used, and it downgraded its earlier advice on the drug prazosin after a negative trial¹.

So the honest summary is this: IRT has more support than any other psychological approach, it is brief, and it has few known downsides. It does not work for everyone, and most of the evidence comes from guided treatment, not from people trying it alone with a notebook.

Trying it on your own, carefully

For ordinary bad dreams that keep coming back, many people try the basic steps themselves. Start with a nightmare that is unpleasant but not overwhelming. Write it out in the present tense, then write the changed version underneath and keep only the new one in mind when you rehearse. Ten minutes a day is enough. If writing the original stirs up more than you can settle within a few minutes, stop and take that as a signal to work with a professional rather than alone.

A dream journal helps here in a plain, practical way: it shows whether the nightmares are becoming less frequent or less intense, which is hard to judge from memory. If the same scene keeps returning, the guide on recurring dreams covers what research says about that pattern.

When to see a clinician

See a doctor, a sleep specialist or a mental health professional if nightmares wake you several times a week, if you are afraid to fall asleep, if they follow a traumatic event, or if they come with daytime symptoms such as flashbacks, low mood, panic or exhaustion. Also seek help if a nightmare started or changed after a new medicine, or if you act out dreams physically in your sleep, because other sleep disorders can need different care.

Seek help urgently if nightmares come with thoughts of ending your life. A meta-analysis of 39 studies found that sleep disturbances, nightmares included, are associated with a higher risk of suicidal thoughts and behaviour, and that the link did not depend on depression⁷. If you are in that place now, contact your local emergency number or a crisis line today. Nightmares are treatable, and that is a reason to ask, not to wait.

Read next

• Recurring dreams: what psychology says
• What a dream journal is and how to keep one
• Lucid dreaming: the basics

Sources

1. Morgenthaler TI, Auerbach S, Casey KR, Kristo D, Maganti R, Ramar K, Zak R, Kartje R (2018). Position paper for the treatment of nightmare disorder in adults: an American Academy of Sleep Medicine position paper. Journal of Clinical Sleep Medicine, 14(6), 1041-1055. doi.org/10.5664/jcsm.7178
2. Krakow B, Zadra A (2006). Clinical management of chronic nightmares: imagery rehearsal therapy. Behavioral Sleep Medicine, 4(1), 45-70. doi.org/10.1207/s15402010bsm0401_4
3. Krakow B, Hollifield M, Johnston L, Koss M, Schrader R, Warner TD, et al. (2001). Imagery rehearsal therapy for chronic nightmares in sexual assault survivors with posttraumatic stress disorder: a randomized controlled trial. JAMA, 286(5), 537-545. doi.org/10.1001/jama.286.5.537
4. Augedal AW, Hansen KS, Kronhaug CR, Harvey AG, Pallesen S (2013). Randomized controlled trials of psychological and pharmacological treatments for nightmares: a meta-analysis. Sleep Medicine Reviews, 17(2), 143-152. doi.org/10.1016/j.smrv.2012.06.001
5. Levin R, Nielsen TA (2007). Disturbed dreaming, posttraumatic stress disorder, and affect distress: a review and neurocognitive model. Psychological Bulletin, 133(3), 482-528. doi.org/10.1037/0033-2909.133.3.482
6. Sandman N, Valli K, Kronholm E, Ollila HM, Revonsuo A, Laatikainen T, Paunio T (2013). Nightmares: prevalence among the Finnish general adult population and war veterans during 1972-2007. Sleep, 36(7), 1041-1050. doi.org/10.5665/sleep.2806
7. Pigeon WR, Pinquart M, Conner K (2012). Meta-analysis of sleep disturbance and suicidal thoughts and behaviors. Journal of Clinical Psychiatry, 73(9), e1160-e1167. doi.org/10.4088/JCP.11r07586