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

Abstract

Background and Objectives: Light therapy (LT) is used as an adjunctive treatment for sleep problems. This study evaluates the impact of LT on sleep quality and sleep-related parameters in patients with sleep disorders. Materials and Methods: We performed a pilot, randomized, open-label clinical trial. Fourteen patients aged 20–60 years with insomnia were randomized into the control and LT groups (1:1 ratio). The LT group was instructed to use a device that provides bright LT (6000 K, 380 lux, wavelength 480 nm) for at least 25 min before 09:00 a.m. for two weeks. A self-reported questionnaire was used to evaluate circadian preference, mood, and sleep-related parameters. We analyzed serum cortisol levels and clock genes’ expression. Results: The Epworth Sleepiness Scale (ESS), insomnia severity index(ISI), and Pittsburgh Sleep Quality index(PSQI) were significantly improved within the LT group only after the two-week period. When comparing the two groups, only the change in ESS was significant (mean difference, control: −0.14 vs. LT: −1.43, p = 0.021) after adjusting for the baseline characteristics. There were no significant differences in serum cortisol or clock genes’ expression. Conclusions: LT can improve daytime sleepiness in patients with sleep disorders; however, further well-designed studies are warranted to confirm its efficacy.

Feasibility and efficacy of pre-sleep dim light therapy for adults with insomnia: A pilot randomized, open-label, two-arm study

“…Based on the pilot study we previously conducted, we calculated the necessary sample size 12 . We determined the necessary total sample size of 40 individuals by applying an alpha 0.05, effect size of 0.53, and power of 0.9, based on the mean ± standard deviation (SD) difference values (-1.286 ± 2.425) observed before and after using the Epworth Sleepiness Scale (ESS) in the group for which conventional light was used.…”

“…LT can be tailored in terms of intensity and correlated color temperature (CCT) for the management of sleep problems 4,12,13 . Research, including our own 4,12,13 , has demonstrated that light with a wavelength of approximately 460 nm can signi cantly modulate melatonin suppression, thereby facilitating sleep regulation. The role of CCT in LT, in uencing melatonin levels and circadian rhythms, is increasingly recognized as a crucial factor in sleep therapy 14 .…”

Assessing the Feasibility and Efficacy of Pre-Sleep Dim Light Therapy for Adults with Insomnia: A Pilot Study

“…LT can be tailored in terms of intensity and correlated color temperature (CCT) for the management of sleep problems [4,15,16]. Research, including our own [4,15,16], has demonstrated that light with a wavelength of approximately 460 nm can significantly modulate melatonin suppression, thereby facilitating sleep regulation. The role of CCT in LT, influencing melatonin levels and circadian rhythms, is increasingly recognized as a crucial factor in sleep therapy [17].…”