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

Abstract

This study assesses the effectiveness of pre-sleep dim light therapy (LT) as a non-pharmacological intervention for insomnia in adults, focusing on its impact on sleep quality and circadian rhythms. Conducted over two weeks, the randomized trial involved 40 adults with sleep disorders. Participants were divided into a control group and an LT group, the latter receiving warm-colored light exposure before bedtime. The methodology combined subjective sleep questionnaires, objective sleep assessments through actigraphy, and molecular analyses of circadian clock gene expression in blood cells. Key results indicated significant improvements in the LT group’s sleep quality and efficiency, and a 30-minute advancement in Dim Light Melatonin Onset compared to the control group. Molecular analysis revealed a notable reduction in CRY1 gene expression, implicating LT’s influence on circadian sleep regulation. While the study’s small sample size and short duration limit its scope, the findings suggest LT’s potential as an effective, non-drug approach for insomnia treatment. The study advocates for expanded research with larger, more diverse cohorts over longer periods to further validate LT’s efficacy in sleep medicine.