Hypnosis for insomnia: what the trials actually show

Two kinds of studies that get mixed up

Most claims about sleep hypnosis rest on two very different kinds of research. Clinical trials give hypnosis to people with poor sleep or insomnia and track outcomes such as sleep diaries over weeks. Lab studies play a single recording to healthy volunteers and measure their brain waves during one nap or night.

Lab studies tell you something about how the brain responds to suggestion. They do not tell you whether hypnosis treats insomnia. It helps to keep the two apart as you read the rest of this post.

What the systematic reviews found

A 2015 meta-analysis by Lam and colleagues found six randomized trials of hypnotherapy and seven of autogenic training or guided imagery, with 502 participants in total. Eleven of the 13 studies had low methodological quality.^[1]

• Compared with a waitlist, hypnotherapy shortened the time it took to fall asleep (standardized mean difference −0.88, 95% CI −1.56 to −0.19).^[1]
• Compared with a sham intervention, there was no significant difference.^[1]
• Autogenic training and guided imagery showed the same pattern.^[1]

The authors concluded that the positive results may not generalize, because samples were small and methods were weak.^[1] Beating a waitlist but not a sham suggests that much of the benefit may come from the attention, relaxation and expectation any structured wind-down routine provides.

A broader 2018 review by Chamine, Atchley and Oken, published in the Journal of Clinical Sleep Medicine, took in 24 studies of hypnosis with at least one sleep outcome, including studies of other conditions that come with sleep problems. It did not pool effect sizes. It counted results.^[2]

The pattern was similar when only studies with lower risk of bias were reviewed. Adverse events were uncommon. The authors called hypnosis “a promising treatment that merits further investigation”, limited by small samples, low study quality and few studies in people with sleep complaints.^[2]

Does the content of the suggestions matter?

A 2018 randomized trial by the same Hong Kong group tested this directly. Sixty participants got four weekly one-hour sessions. Half heard suggestions aimed at insomnia-related worry and arousal. Half heard generic suggestions about distraction, confidence and self-care.^[3]

Both groups improved on sleep efficiency and daytime functioning, and there was no significant difference between them. The authors wrote that this “raises doubts about the value of disease-specific suggestions”. The trial also recorded side effects carefully: they were common (37% to 52%, depending on session content) but mostly mild, and 10% of participants dropped out.^[3]

The deep-sleep lab studies

The best-known sleep hypnosis finding comes from Cordi, Schlarb and Rasch at the University of Zurich. In a 2014 crossover study, 70 healthy young women each napped for 90 minutes twice, once after a hypnotic suggestion to “sleep deeper” and once after a control tape. After the suggestion, slow-wave sleep rose by 81% and time awake fell by 67%, relative to the control condition. The effect did not appear in people with low suggestibility.^[4]

Follow-up work from the same lab extended this to healthy older women (a 57% increase in slow-wave sleep during a nap in those suggestible to hypnosis)^[5] and to a full night in 43 young adults, where highly hypnotizable people had more slow-wave sleep after the suggestion.^[6] The authors noted that further studies are needed to see whether sleep deepens compared with nights with no recording at all.^[6]

One result gets less attention. In people with low hypnotizability, the same suggestion reduced slow-wave sleep. The drop remained when the lab removed the hypnotic induction and called the exercise “guided imagery”.^[7] All of these studies were in healthy volunteers, not people with insomnia. For what deep sleep does, see slow-wave sleep in plain English.

How hypnosis compares with CBT-I

The American Academy of Sleep Medicine’s 2021 guideline gives one strong recommendation for chronic insomnia in adults: multicomponent cognitive behavioral therapy for insomnia (CBT-I). Brief therapies, stimulus control, sleep restriction and relaxation therapy get conditional recommendations. Sleep hygiene alone is not recommended. Hypnosis is not among the recommended therapies.^[8]

The US National Heart, Lung, and Blood Institute describes CBT-I as a 6- to 8-week program that is usually the first treatment option for long-term insomnia.^[9] The problem is access, which we cover in CBT-I works, almost nobody gets it. If worry about sleep itself keeps you awake, see sleep anxiety.

A fair summary: CBT-I has a large, consistent evidence base for chronic insomnia. Hypnosis has small trials with mixed results. The one pooled benefit in the 2015 meta-analysis, against a waitlist, was a shorter time to fall asleep,^[1] which is why sleep onset latency is a sensible thing to track if you try it.

A sensible way to use sleep hypnosis

• If you have chronic insomnia, seek CBT-I first, or use hypnosis alongside it as a wind-down routine, not as a substitute.
• Give it two weeks and measure one thing, such as how long it takes you to fall asleep, rather than judging by one night.
• If you find hypnosis hard to get into and your sleep gets worse, stop. The lab data suggest suggestions to “sleep deeper” may not help everyone.^[7]

Hypnova is a wellness app, not an insomnia treatment, and none of the studies above tested it. For practical setup, see headphones and timing for sleep hypnosis, or start from our hypnosis for sleep page.