The Effects of Light Therapy on Sleep, Agitation and Depression in People With Dementia: A Systematic Review and Meta-analysis of Randomized Controlled Trials

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

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.

Effects of Bright Light Therapy on Agitation Among Older Adults Living with Dementia in Macao: A Pilot Study

A randomized controlled trial was conducted to examine the effects of bright light therapy on agitation in older adults with dementia in Macao. This study involved 31 participants: 10 in the outdoor light treatment group, 11 in the indoor light-box treatment group, and 10 in the control group. Significant reductions in agitation were observed in the two treatment groups over four weeks compared to the control group. However, no statistical difference in cognitive function between experimental and control groups was found. This study supports the use of bright light therapy to reduce agitation in older people with dementia.

Brain FADE syndrome: the final common pathway of chronic inflammation in neurological disease

Importance

While the understanding of inflammation in the pathogenesis of many neurological diseases is now accepted, this special commentary addresses the need to study chronic inflammation in the propagation of cognitive Fog, Asthenia, and Depression Related to Inflammation which we name Brain FADE syndrome. Patients with Brain FADE syndrome fall in the void between neurology and psychiatry because the depression, fatigue, and fog seen in these patients are not idiopathic, but instead due to organic, inflammation involved in neurological disease initiation.

Observations

A review of randomized clinical trials in stroke, multiple sclerosis, Parkinson's disease, COVID, traumatic brain injury, and Alzheimer's disease reveal a paucity of studies with any component of Brain FADE syndrome as a primary endpoint. Furthermore, despite the relatively well-accepted notion that inflammation is a critical driving factor in these disease pathologies, none have connected chronic inflammation to depression, fatigue, or fog despite over half of the patients suffering from them.

Conclusions and relevance

Brain FADE Syndrome is important and prevalent in the neurological diseases we examined. Classical "psychiatric medications" are insufficient to address Brain FADE Syndrome and a novel approach that utilizes sequential targeting of innate and adaptive immune responses should be studied.

35 years of light treatment for mental disorders in the Netherlands

BACKGROUND

Light therapy (LT) for Seasonal Affective Disorders (SAD) has been a well-known and effective treatment for 40 years. The psychiatric university clinic of Groningen, the Netherlands was an early adopter and started research and treatment of SAD in 1987. Research projects on mechanisms, the role of the circadian system, treatment optimization, and investigating new areas for the effects of light treatment have been carried out ever since, leading to a widespread interest across the country.

OBJECTIVE

To provide an overview and description of the historical development of LT for mental disorders in the Netherlands.

METHODS

A non-systematic, review of research on light treatment for mental problems in the Netherlands, published since 1987 was conducted.

RESULTS

The fields of LT and chronotherapy are strongly based in the scientific interests of both chrono-biologists and therapists in the Netherlands. LT has shown effectiveness in treating mood disorders. Likewise, results for other mental disorders have shown some promise, but so far, the outcomes are not always unequivocal and have not always been based on robust data. Ongoing research is discussed.

CONCLUSIONS

LT, and in addition exposure to the right light at the right time is an important issue in mental health. Over the past 3 decades research on light and LT in the Netherlands has become well established and is still growing.

The Effects of Light Therapy for Depression in Dementia: A Systematic Review and Meta-Analysis

BACKGROUND

Depression is one of the most common symptoms in patients with dementia.

OBJECTIVE

This meta-analysis aimed to evaluate the effect of light therapy on depression associated with dementia by using a single scale.

METHODS

Published studies based on the terms including "Dementia", "depression", and "Phototherapy" were searched. Web of Science, PubMed, Embase, CiNii, CNKI, Wanfang Database, and China Biology Medicine disc were adopted to collect randomized controlled studies or cross-controlled studies using the Cornell Dementia Depression Scale (CSDD) until February 2022. GRADE and Review Manager Version 5.4.1 were employed to assess the risk of bias. A meta-analysis was conducted by R 4.0.2 software based on the changes in CSDD scores.

RESULTS

A total of 1,055 studies were retrieved from the databases, and six studies were included after screening. Some 406 people with dementia were included with an average age of over 80 years. Forest plot results showed that light intervention improved depression scores of dementia patients (MD = -2.59, 95% CI: -4.46 to -0.71), and light intensity less than 1000 lux improved depression symptoms of dementia patients (MD = -2.76, 95% CI: -4.55 to -0.97). An intervention that lasted 8 to 12 weeks was the most effective (MD = -3.77, 95% CI: -6.93 to -0.60), and non-stable interventions such as ceiling LED lights exerted more positive effects (MD = -2.12, 95% CI: -3.38 to -0.85).

CONCLUSION

The overall results of the meta-analysis suggested that light intervention can improve the depressive symptoms of older patients with dementia.