A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials Evaluating the Evidence Base of Melatonin, Light Exposure, Exercise, and Complementary and Alternative Medicine for Patients with Insomnia Disorder

Abstract

Insomnia is a prevalent disorder and it leads to relevant impairment in health-related quality of life. Recent clinical guidelines pointed out that Cognitive-Behavior Therapy for Insomnia (CBT-I) should be considered as first-line intervention. Nevertheless, many other interventions are commonly used by patients or have been proposed as effective for insomnia. These include melatonin, light exposure, exercise, and complementary and alternative medicine. Evaluation of comparable effectiveness of these interventions with first-line intervention for insomnia is however still lacking. We conducted a systematic review and network meta-analysis on the effects of these interventions. PubMed, PsycInfo, PsycArticles, MEDLINE, and CINAHL were systematically searched and 40 studies were included in the systematic review, while 36 were entered into the meta-analysis. Eight network meta-analyses were conducted. Findings support effectiveness of melatonin in improving sleep-onset difficulties and of meditative movement therapies for self-report sleep efficiency and severity of the insomnia disorder. Some support was observed for exercise, hypnotherapy, and transcranial magnetic resonance, but the number of studies for these interventions is still too small. None of the considered interventions received superior evidence to CBT-I, which should be more widely disseminated in primary care.

Effects of Exercise on Sleep Quality and Insomnia in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

“…Two published meta-analysis articles, respectively, explored the effects of exercise only on middle-aged women ( 65 ) and pregnant women ( 66 ). Some other meta-analysis studies assessed whether exercise improves sleep in adults who already have a diagnosis of insomnia ( 67 , 68 ). One of them appraised several alternative interventions for participants with insomnia, including exercise, melatonin, and others.…”

“…They found exercise was efficacious in ameliorating self-reported SOL with small-to-medium effects. However, the number of eligible studies for exercise intervention is still small to confirm the above conclusion ( 68 ). Herein, our study focused on the sleep-enhancing effects of exercise on the whole adult population, not limiting the initial sleep conditions of participants as the participants in most RCTs were not necessarily all diagnosed with insomnia but they were still experiencing or susceptible to poor sleep conditions.…”

The Uniqueness of Tryptophan in Biology: Properties, Metabolism, Interactions and Localization in Proteins

“…Melatonin helps to maintain the circadian clock of the body, particularly the wake–sleep cycle, comprising of ~16 h of daytime activity and ~8 h of nightly sleep [ 39 ]. It is generally safe to use and is used to treat insomnia, jet lag and various sleep disorders, thrombocytopenia (chemo-induced), ‘winter blues’ and seasonal affective disorder (SAD), and tardive dyskinesia [ 40 , 41 , 42 , 43 ]. Melatonin also has some immune-regulatory and anticancer effects, but these effects need further studies and validation [ 44 , 45 ].…”

Effects of cognitive behavioral therapy for insomnia on subjective and objective measures of sleep and cognition

“…Inactive wait-list groups are considered to be an efficient control of time and placebo effect to an active intervention compared to 'No Treatment' 75 , however, it might have impacted the motivation to remain in the study. To retain motivation, future studies might consider using an active control group who undertake an intervention that have been proved to yielded smallto-moderate effect size on insomnia severity (e.g., self-guided relaxation training, exercise) 76,77 . Moreover, the variability in attrition highlights the difficulties faced with such demanding and complicated trials in chronic insomnia.…”