Light interventions and sleep, circadian, behavioral, and psychological disturbances in dementia: A systematic review of methods and outcomes

Gunnhild J Hjetland; Ståle Pallesen; Eirunn Thun; Eirin Kolberg; Inger H Nordhus; Elisabeth Flo

doi:10.1016/j.smrv.2020.101310

Light interventions and sleep, circadian, behavioral, and psychological disturbances in dementia: A systematic review of methods and outcomes

Sleep Med Rev. 2020 Aug:52:101310. doi: 10.1016/j.smrv.2020.101310. Epub 2020 Mar 19.

Authors

Gunnhild J Hjetland¹, Ståle Pallesen², Eirunn Thun³, Eirin Kolberg⁴, Inger H Nordhus⁵, Elisabeth Flo⁴

Affiliations

¹ Department of Clinical Psychology, Faculty of Psychology, University of Bergen, Norway; City Department of Health and Care, City of Bergen, Norway. Electronic address: Gunnhild.Hjetland@uib.no.
² Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Norway; Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Bergen, Norway.
³ Department of Clinical Psychology, Faculty of Psychology, University of Bergen, Norway; Department of Psychosocial Science, Faculty of Psychology, University of Bergen, Norway.
⁴ Department of Clinical Psychology, Faculty of Psychology, University of Bergen, Norway.
⁵ Department of Clinical Psychology, Faculty of Psychology, University of Bergen, Norway; Department of Behavioral Sciences in Medicine, Faculty of Medicine, University of Oslo, Norway.

PMID: 32289734
DOI: 10.1016/j.smrv.2020.101310

Abstract

Dementia is a devastating disease with a global impact, and there is an urgent need for effective interventions to alleviate the accompanying disturbances in behavior, mood, sleep, and circadian rhythms. Bright light treatment (BLT) is a promising non-pharmacological intervention; however, studies have yielded conflicting results. This systematic review provides a comprehensive overview of the effect of BLT in dementia, with a specific focus on how study characteristics might have affected the available results. The included studies were small and comprised time-limited interventions and follow-ups. Light values, adherence to treatment, and time of year were not consistently reported. Varying designs, methods, and population characteristics such as age, gender, dementia diagnosis, circadian phase, and baseline symptoms may have moderated the outcomes and affected review results. The use of crossover designs and too high illumination as placebo lights might have nullified positive effects of BLT. Because some studies had negative outcomes after ambient BLT with high amounts of short wavelengths, more modest light levels should be further investigated. Employing rigorous designs and detailed reporting of intervention characteristics, i.e., the illumination, correlated color temperature, timing, and duration of light utilized, are of utmost importance to establish the optimal treatment approach in this population. Systematic review registration number: PROSPERO CRD42017051004.

Keywords: Behavioral and psychological symptoms of dementia; Bright light therapy; Circadian rhythm; Dementia; Sleep.

Publication types

Research Support, Non-U.S. Gov't
Review
Systematic Review

MeSH terms

Circadian Rhythm / physiology*
Dementia* / complications
Dementia* / psychology
Depression / psychology
Humans
Outcome Assessment, Health Care*
Phototherapy*
Sleep Wake Disorders / etiology
Sleep Wake Disorders / psychology*