Complementary and alternative approaches
European guidelines for diagnosing and treating insomnia12 do not recommend Valerian and other phytotherapeutics, acupuncture, aromatherapy, and foot reflexology to treat insomnia because of poor evidence. Notably, these approaches and products are popular worldwide and have been increasingly studied over the past two decades to treat sleep disorders.
Light therapy is the use of light in the treatment of physical or mental illnesses. When natural sunlight is not appropriate, light therapy boxes mimicking outdoor light might provide an alternative to adjust normal circadian rhythm. The fact that light inhibits the secretion of melatonin and that the hypothalamus through the retinohypothalamic tract controls circadian rhythms provides better insight into how light therapy can be used to treat sleep disorders.60,61 In studies of insomnia therapy, the mean reported light intensity was 4800 lux.62 With coauthors in their systematic review with meta-analysis, Van Maanen reported light therapy to be effective for insomnia symptoms and recommend it as a complementary method to insomnia management.62 On the other hand, light therapy can be questionable in patients with photosensitivity and epilepsy.
Music therapy is the therapeutic use of music to promote patients’ mental and bodily health. Listening to music is a complicated process accompanied by the activation of different brain parts with a complex response, e.g., cognitive and emotional. Särkämö and colleagues, in poststroke patients listening to music of their own choice, reported mood improvement and cognitive enhancement.63 Nilsson documented stress reduction in patients who underwent cardiac surgery after 30 minutes of listening to soft and relaxing melodies with a volume of 50 to 60 dB.64 In their systematic review from 2017, Feng et al. documented that listening to relaxing music improves sleep onset latency and overall sleep quality in primary insomniacs.65
Aromatherapy is based on the usage of concentrated essential oils extracted from fragrant floral parts to improve mental and physical health. Aromatherapy is usually administered by either inhalation or skin application.66 A possible explanation for aromatherapy’s efficacy ranges from subjective psychological to direct biological action.67 Some essential oils contain terpenes that cross the blood-brain barrier and possess cholinergic activity or act on gamma-aminobutyric acid receptors.68 Certain odors, e.g., linalool and linalyl acetate extracted from lavender, may induce sedation and relaxation.69 In their systematic review from 2019, Lin and coauthors also highlighted the results’ limitations and documented that aromatherapy can be effectively used to improve sleep quality.70 The study mentioned above is in line with Hwang and colleagues’ previously published work, which documented aromatic oils extracted from lavender and bergamot to be most commonly studied.71
Massage is a thousands of years old technique involving mechanical contact on the patient’s body, commonly used in medicine, sports-related regeneration, and wellness. More than one hundred massage types are known. In the literature, the influence of massage therapy on the improvement of depression and anxiety was documented.72 A possible massage therapy mechanism for stress relief is decreased cortisol levels and an increase in active neurotransmitters, such as serotonin and dopamine 73Hachul and colleagues reported improved sleep in postmenopausal women with insomnia symptoms after massage therapy.74
Acupuncture and acupressure arise from traditional Chinese medicine, characterized by the insertion of metallic needles into or through the skin or applying mechanical pressure at specific sites. The techniques mentioned above are believed to restore the proper flow of vital energy, known as qi. The study by Jinhuan and coauthors has shed more light on the effects of acupuncture for insomnia. They analyzed fifteen studies involving 1108 patients and found acupuncture superior to placebo in treating insomnia.75 On the other hand, in 2019, He and coworkers published an overview of 34 systematic reviews assessing acupuncture to treat insomnia. They recommended a cautious interpretation of the promising results, as the included studies’ quality was generally low.76 Regarding existing evidence of the acupressure effect on sleep quality, one systematic review with meta-analysis reported an improvement in the Pittsburgh Sleep Quality index compared with sham treatment. However, the authors also identified a high risk of bias due to the absence of blinding patients.77
Herbal medicine represents a commonly used complementary/alternative approach to health promotion or disease treatment. It refers to the utilization of plants or herbal nutritional supplements for therapeutic purposes. Forms in which herbs can be administered usually comprise herbal teas or plant extracts. Herbal dietary supplements are widely used worldwide. E.g., up to one-quarter of adults in the US report the use of an herb to treat a medical condition.78 Some empirical studies explain the possible sedative-hypnotic effect of some medical plants via interaction with the neurotransmitter gamma amino-butyric acid and its receptors.79 In 2015, Ni, with coauthors in their systematic review with meta-analysis of RCT’s found Chinese herbal medicine (CHM) superior to placebo with respect to its effect on selected sleep quality parameters. However, due to heterogeneity, the typical effect of CHM for insomnia could not be determined. As such, the original studies’ overall poor quality requires a cautious interpretation of the results.80 One of the most commonly used herbal medicines for insomnia is Valeriana officinalis. In a recent study, Shinjyo and colleagues, in their systematic review with meta-analysis, concluded that valerian root could be a safe and useful herb to treat sleep problems. Notably, they also reported no severe adverse events associated with valerian intake. Of note, ’drinking a tea ritual’ before bed can help relieve stress and promote restorative sleep.