Hypnotherapy for insomnia : a systematic review and meta-analysis and a randomized controlled trial

Abstract

Insomnia is a disabling and prevalent sleep disorder that has significant negative impact on one’s physical and mental health as well as quality of life. Although hypnotherapy has been used for the treatment of insomnia, its efficacy and safety have never been systematically examined under a rigorous framework, and there is also no local study. This study is therefore aimed to fill this research gap. It is consisted of two parts: in the first part, a systematic review and meta-analysis was conducted to critically examine the existing evidence for the effectiveness of hypnotherapy for insomnia; in the second part, a randomized controlled trial (RCT) was conducted to validate the benefits of hypnotherapy for insomnia using well-documented screening, validated subjective scales and comprehensive adverse events monitoring procedures. Using a board definition that included guided imagery and autogenic training under the umbrella of hypnotherapy, a total of 13 RCTs were included for systematic review and meta-analysis. A majority of the included RCTs reported that hypnotherapy significantly improved insomnia compared to waitlist; yet, there were methodological shortcomings in the studies, including imprecise diagnostic procedure, problems with randomization, blinding issues, and insufficient data on safety. In the second part of my study, which was conducted from September 2015 to January 2017, 60 Chinese adults who met the fifth edition of the Diagnostic and Statistical Manual (DSM-5) criteria for insomnia disorder for at least 12 months were randomized to hypnotherapy or sham hypnotherapy. Subjects in both groups received weekly one-hour training session for 4 consecutive weeks to learn self-hypnosis. Outcome measures included Insomnia Severity Index (ISI),, other questionnaires, and sleep-diary-derived variables, such as sleep efficiency (SE). Repeated measures analysis of variance (ANOVA) showed that there was a significant time effect in ISI, SE and most of the other outcome measures in both hypnotherapy and sham hypnotherapy groups, but the between-group difference was not significant. Only minor, transient and self-relieved adverse events were reported. Results suggested that hypnotherapy and sham hypnotherapy was equally effective and safe in the short-term treatment of chronic insomnia. Yet, the generalizability of the positive results was limited due to our small sample size, some missing in follow-up data and potential selection and reporting bias. Results of the present studies suggest that individuals who experience insomnia can be benefitted from self-hypnotherapy training, which is safe, pleasurable, and promotes participation, self-exploration, and self-efficacy.