Light therapy in insomnia disorder: A systematic review and meta‐analysis

Abstract

SummaryIn the management of insomnia, physicians and patients are seeking alternative therapeutics to sleeping pills, in addition to sleep hygiene and cognitive behavioural therapy. Bright light therapy (LT) has proven its efficacy in circadian and mood disorders. We conducted a systematic literature review and meta‐analysis according to Cochrane and PRISMA guidelines and using the databases Medline, Cochrane, and Web of Science, with a special focus on light therapy and insomnia. Twenty‐two studies with a total of 685 participants were included, five of which with a high level of proof. Meta‐analysis was performed with 13 of them: light therapy for insomnia compared with control conditions significantly improved wake after sleep onset (WASO: SMD = −0.61 [−1.11, −0.11]; p = 0.017; weighted difference of 11.2 min ±11.5 based on actigraphy, and SMD = −1.09 [−1.43, −0.74] (p < 0.001) weighted difference of −36.4 min ±15.05) based on sleep diary, but no other sleep measures such as sleep latency, total sleep time (TST), or sleep efficiency. Qualitative analysis of the review showed some improvement mainly in subjective measures. Morning light exposure advanced sleep–wake rhythms and evening exposure led to a delay. No worsening was observed in objective nor subjective measures, except for TST in one study with evening exposure. A light dose–response may exist but the studies’ heterogeneity and publication bias limit the interpretation. To conclude, light therapy shows some effectiveness for sleep maintenance in insomnia disorders, but further research is needed to refine the light parameters to be chosen according to the type of insomnia, in the hope of developing personalised therapeutics.

The European Insomnia Guideline: An update on the diagnosis and treatment of insomnia 2023

“…A meta-analysis on light therapy for insomnia showed small positive effects on sleep (Van Maanen et al, 2016) and this is an area worthy of further investigation, especially because a circadian sleep-wake rhythm disorder is frequently comorbid with insomnia. Chambe et al (2023) came to similar conclusions: light therapy may have some promise, but further RCTs are necessary.…”

Feasibility and Efficacy of Morning Light Therapy for Adults with Insomnia: A Pilot, Randomized, Open-Label, Two-Arm Study

“…LT is natural, simple, relatively inexpensive, and useful as an adjuvant treatment for sleep disorders due to its few interactions with other treatment options. A systematic review and meta-analysis, which involved 22 studies and 685 participants, demonstrated the significant improvement of wake after sleep onset with LT in managing insomnia, supporting the overall effectiveness of LT in treating sleep problems [ 21 ], as highlighted by another meta-analysis of 53 studies involving 1154 participants [ 19 ]. However, only a few studies have examined the effects of LT on sleep-related parameters.…”

“…Therefore, it is necessary to prevent disharmony in the circadian rhythm and maintain a balanced state by providing light with the appropriate timing, intensity, duration, and wavelength, similar to natural light; however, modern city lifestyles make this difficult. There are many studies that investigate the utility of sources of artificial lighting in the management of sleep problems [ 19 , 20 , 21 ]. Pharmacological agents, cognitive behavioral therapy, and psychosocial interventions have been traditionally used to treat sleep problems, but light therapy (LT) is receiving more attention due to the limitations that accompany the traditional therapies, such as drug side effects, cost, and limitations of time and space [ 22 , 23 ].…”

Enhancing title and abstract screening for systematic reviews with GPT-3.5 turbo

“…To execute this task, a recently published SR titled ‘Light Therapy in Insomnia Disorder: A Systematic Review and Meta-Analysis’ was selected, and the databases were queried using the keywords stipulated in the original paper. 5 Two key rationales underpinned the selection of this review: first, it yielded a relatively moderate number of studies, and second, its eligibility criteria were somewhat subjective, and challenging to discern during the screening process, making it a suitable testbed to evaluate GPT-3.5’s capabilities. For instance, this study enrolled patients experiencing sleep difficulties but did not specify the particular types of sleep disorders although reviewers did not face much trouble but models had difficulties with studies that included patients with secondary sleeping troubles like patients with cancer.…”

“…These numpy arrays, along with the numpy arrays generated by the researchers, were employed to compute sensitivity, specificity, accuracy and the F1 score for both the researchers and the prompts. The labels used as the ‘gold standard’ were the studies included in the selected SR. 5 …”