The science
Built on what sleep medicine actually recommends.
Nightmares are common and treatable, and the best-supported method is simple, drug-free and takes a few minutes a day. Every method in Baku carries an evidence label, and every claim links to its source. Where evidence is thin, we say so.
4–10%
of adults have nightmares at least once a week.
Levin and Nielsen, 2007
~4%
have nightmare disorder: frequent nightmares plus real distress.
AASM, 2018
10–20 min
of daily rehearsal is all imagery rehearsal asks, after a one-time rewrite.
AASM, 2018
Methods
What each method is, how strong the evidence is, and where it lives in Baku.
| Approach | What it is | Evidence | Why we say so | In Baku |
|---|---|---|---|---|
| Imagery rehearsal therapyIRT | Change the nightmare’s story while awake, then rehearse the new version for 10 to 20 minutes a day. You don’t need to relive the whole nightmare. | Strong evidence | Recommended by the American Academy of Sleep Medicine (2018) for nightmare disorder and for nightmares related to PTSD. Landmark randomised trial in JAMA (Krakow, 2001). [1][2] | The Rewrite studio, 7 days of rehearsal for each new ending, and the 4-week Rewrite program. |
| Insomnia methodsCBT-I elements | A regular schedule, bed only for sleep, getting up rather than lying awake for long (in practice often after 15 to 20 minutes), and worry time early in the evening. | Strong evidence | The first-line treatment for insomnia, which often comes with nightmares. Also listed by the AASM for nightmares related to PTSD. [7][1] | The ritual builder, “Close the day”, and the back-to-sleep rules in Nightlight. |
| Relaxation and slow breathing | Progressive muscle relaxation, a body scan, and slow breathing with long exhales (cyclic sighing). | Good evidence | Muscle relaxation is an AASM-listed option. In a 2023 Stanford randomised study, cyclic sighing improved mood and lowered physiological arousal. [1][6] | Haptic breathing you can feel with your eyes closed, and guided audio. |
| Imagery rehearsal plus a sound cuetargeted memory reactivation | A sound is paired with the new ending during rehearsal, then played softly during REM sleep to reactivate it. | Emerging | In a randomised study in Current Biology (2022) with 36 adults, everyone heard the sound in REM sleep; those for whom it had been paired with their rewritten ending improved faster. It used a sleep headband. [3] | A night cue, opt-in and clearly labelled experimental, after launch. We will measure whether it helps before we promote it. |
| Lucid dreaming therapy | Learning to notice that you are dreaming, then changing the dream from within. | Emerging | An AASM-listed option for nightmare disorder. Studies are small and results are mixed. [1][9] | An optional Lucid path later on. Never the default. |
| Trauma-focused therapiesERRT, CBT for PTSD, EMDR | Clinician-led treatments for nightmares that are tied to trauma. | Good evidence | Listed by the AASM for nightmares related to PTSD. They need a trained professional. [1] | Gentle routing to human help. Baku can sit alongside therapy, never instead of it. |
| Dream incubation | Choosing a theme before sleep to make it more likely to appear in a dream. | Exploratory | Targeted dream incubation (MIT, 2020) steered dream content in the lab. [8] | Tonight’s intention, and a playful “Did it show up?” in the morning. |
| Triggers and lifestyle | Alcohol (REM sleep rebounds later in the night), sleep loss, stress, and starting or stopping some medications. | Good evidence | Well described in sleep medicine; how much each matters varies from person to person. [13] | Optional evening check-ins, your own patterns over time, and “ask your doctor” prompts for medication. |
| Wearable nightmare interruption | A smartwatch detects heart-rate and movement patterns and vibrates to interrupt a nightmare. | Medical device territory | NightWare received FDA authorisation in 2020 as a prescription device for nightmares related to PTSD. [15] | Not in Baku. This is medical-device territory. |
Evidence labels
Five labels, used everywhere.
The same labels appear next to every method in the app, every Atlas page and every claim on this site. They are reviewed by our clinical advisor before launch.
- Strong evidence
- Recommended in clinical guidelines and supported by several randomised trials.
- Good evidence
- Supported by trials or guidelines, with some limits on how far results reach.
- Emerging
- Promising early studies, often small. We label it and measure before promoting it.
- Exploratory
- Lab findings or surveys. Interesting, not yet proof. Offered as play, not treatment.
- Medical device territory
- Medical-device territory. Not part of Baku.
The Rewrite method, as the app teaches it
Four steps, repeated gently.
- 01
Pick a nightmare
A milder one first. It makes the method easier to learn.
- 02
Change it any way you want
A new ending, a helper, a new place, a power, or make it absurd.
- 03
Rehearse 10 to 20 minutes a day
Read it once, then live it with your eyes closed, for about a week.
- 04
Repeat with the next one
Check in: is it coming less often? Then choose the next dream.
Works with your wearable
What a wearable can tell you, and what it cannot.
Baku can read sleep from Apple Health, Health Connect, WHOOP and Oura. Compared with a sleep laboratory, consumer devices were very good at detecting sleep, less good at catching time awake, inconsistent on sleep stages, and less accurate on disturbed nights. So Baku uses them for patterns across your own nights, shows the wakes a device noticed as suggestions you confirm, and never presents a number as a sign that something is wrong. It only reads: it never wakes you or vibrates during a nightmare, which is medical-device territory. [12]
Watches and rings estimate sleep stages from movement and heart rate. They are useful for seeing patterns over weeks, but they are not a sleep lab, so Baku shows them as approximate and never as a diagnosis.
What Baku reads, and what it never does with it: sleep data in our privacy policy.
iPhone
Apple Health
Read on your phone. Brings in Apple Watch, and other watches and rings whose app shares sleep with Apple Health.
Android
Health Connect
Read on your phone. Brings in Samsung, Fitbit, Garmin, Withings and other devices whose app shares sleep with Health Connect.
iPhone and Android
WHOOP
Connected directly with your WHOOP account. Your last 30 nights arrive within a minute, then every new night.
iPhone and Android
Oura
Connected directly with your Oura account. Your last 30 nights arrive within a minute, then every new night.
What Baku will never say
Proof, not promises.
- That it diagnoses or treats a medical condition, or replaces a doctor or therapist.
- That a dream predicts the future, or that a symbol means something bad will happen.
- Precise outcome numbers before we have measured our own results.
Instead we say “research suggests”, “may help” and “many people find”, and we link the study.
Clinical advisor
Announced before launch.
A sleep psychologist experienced in imagery rehearsal reviews the Rewrite flow, the safety rules, the onboarding questions and every evidence label before Baku opens to the public. Their name will appear here, with what they reviewed.
Are you a sleep scientist or therapist who would like to help? Write to us.
Safety
When it is more than a bad dream.
Nightmares tied to trauma deserve a professional, and Baku can sit alongside therapy, never instead of it. If anything you write suggests a crisis, Baku shows local, human help straight away, before anything else. It is not a crisis service, and it never handles acute crisis alone. Baku is for people aged 16 and over in Switzerland, the EU and the UK, and 13 and over elsewhere. Crisis lines by country.
Sources
Where the claims come from.
- 1Morgenthaler TI, et al. Position paper for the treatment of nightmare disorder in adults: an American Academy of Sleep Medicine position paper. Journal of Clinical Sleep Medicine, 2018. Link
- 2Krakow B, et al. Imagery rehearsal therapy for chronic nightmares in sexual assault survivors with posttraumatic stress disorder: a randomized controlled trial. JAMA, 2001. Link
- 3Schwartz S, Clerget A, Perogamvros L. Enhancing imagery rehearsal therapy for nightmares with targeted memory reactivation. Current Biology, 2022. Link
- 4Schredl M. Nightmare frequency and nightmare topics in a representative German sample. European Archives of Psychiatry and Clinical Neuroscience, 2010. Link
- 5Levin R, Nielsen TA. Disturbed dreaming, posttraumatic stress disorder, and affect distress: a review and neurocognitive model. Psychological Bulletin, 2007. Link
- 6Balban MY, et al. Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine, 2023. Link
- 7Edinger JD, et al. Behavioral and psychological treatments for chronic insomnia disorder in adults: an American Academy of Sleep Medicine clinical practice guideline. Journal of Clinical Sleep Medicine, 2021. Link
- 8Haar Horowitz A, et al. Dormio: a targeted dream incubation device. Consciousness and Cognition, 2020. Link
- 9Konkoly KR, et al. Real-time dialogue between experimenters and dreamers during REM sleep. Current Biology, 2021. Link
- 10Nielsen T, Powell RA. Dreams of the Rarebit Fiend: food and diet as instigators of bizarre and disturbing dreams. Frontiers in Psychology, 2015. Link
- 11Nielsen TA, et al. Immediate and delayed incorporations of events into dreams: further replication and implications for dream function (the dream-lag effect). Journal of Sleep Research, 2004. Link
- 12Chinoy ED, et al. Performance of seven consumer sleep-tracking devices compared with polysomnography. Sleep, 2021. Link
- 13Carskadon MA, Dement WC. Normal human sleep: an overview. Principles and Practice of Sleep Medicine, Elsevier, 2017.
- 14Domhoff GW. The Mystique of Dreams: A Search for Utopia Through Senoi Dream Theory. University of California Press, 1985.
- 15U.S. Food and Drug Administration De Novo classification request DEN200033: NightWare, granted 6 November 2020. FDA De Novo database, 2020. Link
- 16Babylonian Talmud Berakhot 55a–b. Sefaria, c. 500 CE. Link
- 17Sahih al-Bukhari Book of the Interpretation of Dreams. sunnah.com, 9th century. Link
- 18Sharpless BA, Barber JP. Lifetime prevalence rates of sleep paralysis: a systematic review. Sleep Medicine Reviews, 2011. Link
For anyone who wakes at 3 a.m.
Give your nightmares to Baku.
Rewrite the dreams that keep coming back, and keep a quiet, warm light for 3 a.m. Coming to iPhone and Android.
Join the waitlist