The Effects of Light Therapy on Sleep, Depression, Neuropsychiatric Behaviors, and Cognition Among People Living With Dementia: A Meta-Analysis of Randomized Controlled Trials

Nur Aini; Ruey Chen; Hsin Chu; Ching-Yi Chang; Hui-Chen Lin; Hsiu-Ju Jen; Doresses Liu; Tso-Ying Lee; Kuei-Ru Chou

doi:10.1016/j.jagp.2023.12.010

The Effects of Light Therapy on Sleep, Depression, Neuropsychiatric Behaviors, and Cognition Among People Living With Dementia: A Meta-Analysis of Randomized Controlled Trials

Am J Geriatr Psychiatry. 2023 Dec 23:S1064-7481(23)00517-1. doi: 10.1016/j.jagp.2023.12.010. Online ahead of print.

Authors

Nur Aini¹, Ruey Chen², Hsin Chu³, Ching-Yi Chang⁴, Hui-Chen Lin⁵, Hsiu-Ju Jen⁶, Doresses Liu⁷, Tso-Ying Lee⁸, Kuei-Ru Chou⁹

Affiliations

¹ School of Nursing, College of Nursing (NA, RC, CYC, HCL, HJJ, DL, TYL, KRC), Taipei Medical University, Taipei, Taiwan; Nursing Department, Faculty of Health Sciences (NA), University of Muhammadiyah Malang, Indonesia.
² School of Nursing, College of Nursing (NA, RC, CYC, HCL, HJJ, DL, TYL, KRC), Taipei Medical University, Taipei, Taiwan; Department of Nursing (RC, HJJ, KRC), Taipei Medical University-Shuang Ho Hospital, New Taipei, Taiwan; Post-Baccalaureate Program in Nursing (RC), College of Nursing, Taipei Medical University, Taipei, Taiwan.
³ Institute of Aerospace and Undersea Medicine (HC), School of Medicine, National Defense Medical Center, Taipei, Taiwan; Department of Neurology (HC), Tri-Service General Hospital, Taipei, Taiwan.
⁴ School of Nursing, College of Nursing (NA, RC, CYC, HCL, HJJ, DL, TYL, KRC), Taipei Medical University, Taipei, Taiwan.
⁵ School of Nursing, College of Nursing (NA, RC, CYC, HCL, HJJ, DL, TYL, KRC), Taipei Medical University, Taipei, Taiwan; Research Center in Nursing Clinical Practice (HCL, DL, KRC), Wan Fang Hospital Taipei Medical University, Taipei, Taiwan.
⁶ School of Nursing, College of Nursing (NA, RC, CYC, HCL, HJJ, DL, TYL, KRC), Taipei Medical University, Taipei, Taiwan; Department of Nursing (RC, HJJ, KRC), Taipei Medical University-Shuang Ho Hospital, New Taipei, Taiwan.
⁷ School of Nursing, College of Nursing (NA, RC, CYC, HCL, HJJ, DL, TYL, KRC), Taipei Medical University, Taipei, Taiwan; Research Center in Nursing Clinical Practice (HCL, DL, KRC), Wan Fang Hospital Taipei Medical University, Taipei, Taiwan; Department of Nursing (DL), Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
⁸ School of Nursing, College of Nursing (NA, RC, CYC, HCL, HJJ, DL, TYL, KRC), Taipei Medical University, Taipei, Taiwan; Department of Nursing, Nursing Research Center (TYL), Taipei Medical University Hospital, Taipei, Taiwan.
⁹ School of Nursing, College of Nursing (NA, RC, CYC, HCL, HJJ, DL, TYL, KRC), Taipei Medical University, Taipei, Taiwan; Department of Nursing (RC, HJJ, KRC), Taipei Medical University-Shuang Ho Hospital, New Taipei, Taiwan; Research Center in Nursing Clinical Practice (HCL, DL, KRC), Wan Fang Hospital Taipei Medical University, Taipei, Taiwan; Psychiatric Research Center (KRC), Taipei Medical University Hospital, Taipei, Taiwan; Neuroscience Research Center (KRC), Taipei Medical University, Taipei, Taiwan. Electronic address: kueiru@tmu.edu.tw.

PMID: 38216355
DOI: 10.1016/j.jagp.2023.12.010

Abstract

Objective: Alterations in the suprachiasmatic nucleus due to underlying pathologies disrupt the circadian rhythms in people living with dementia (PLWD). Circadian rhythms significantly impact sleep, emotional, and cognitive functions, with its synchronization depending on light exposure. We performed a meta-analysis to evaluate the effects of light therapy on sleep, depression, neuropsychiatric behaviors, and cognition among PLWD.

Methods: A systematic search was conducted in Cochrane, ClinicalTrials.gov, Embase, EBSCOhost, Ovid-MEDLINE, PubMed, Scopus, Web of Science, and CINAHL databases. The pooled effect size was calculated using the Hedges' g with random-effects model adopted in comprehensive meta-analysis software. The Cochrane risk of bias (RoB 2.0) tool evaluated the quality of studies, while Cochrane's Q and I² tests assessed heterogeneity.

Results: A total of 24 studies with 1,074 participants were included. Light therapy demonstrated small-to-medium effects on improving sleep parameters: total sleep time (Hedges' g = 0.19), wake after sleep onset (Hedges' g = 0.24), sleep efficiency (Hedges' g = 0.31), sleep latency (Hedges' g = 0.35), circadian rhythm (acrophase: Hedges' g = 0.36; amplitude: Hedges' g = 0.43), number of night awakenings (Hedges' g = 0.37), sleep disturbance (Hedges'g = 0.45), and sleep quality (Hedges' g = 0.60). Light therapy showed small-to-medium effect on reducing depression (Hedges' g = -0.46) with medium-to-large effect on cyclical function (Hedges' g = -0.68) and mood-related signs and symptoms (Hedges' g = -0.84) subscales. Light therapy also demonstrated small effect on reducing neuropsychiatric behaviors (Hedges' g = -0.34) with medium-to-large effect on agitation (Hedges' g = -0.65), affective symptom (Hedges' g = -0.70), psychosis (Hedges' g = -0.72), and melancholic behavior (Hedges' g = -0.91) subscales. Additionally, light therapy also improved cognition (Hedges' g = 0.39).

Conclusion: Light therapy could be used as a supportive therapy to improve sleep, depression, cognition, and neuropsychiatric behaviors among PLWD.

Keywords: dementia; depression; light therapy; meta-analysis; neuropsychiatric behaviors; sleep.