The effects of bright light treatment on affective symptoms in people with dementia: a 24-week cluster randomized controlled trial

Abstract

Background The majority of people with dementia have behavioral and psychological symptoms of dementia (BPSD), including depression, anxiety and agitation. These may be elicited or aggravated by disrupted circadian rhythms. Bright light treatment (BLT) is a promising non-pharmacological approach to the management of BPSD, but previous research has yielded mixed results. Methods Eight nursing home dementia units (1 unit = 1 cluster) with 78 patients were invited to participate in a cluster randomized controlled trial from September 2017 to April 2018 investigating the effects of BLT on sleep and circadian rhythms (primary outcome) and BPSD (secondary outcome). Ceiling mounted LED-panels were installed in the intervention group (four units), providing light at 1000 lx and 6000 K (vertically at 1.2 m) between 10 a.m. and 3 p.m., with lower values in the mornings and evenings. Standard indoor light was used in the control group (four units). BPSD were assessed with The Cornell Scale for Depression in Dementia (CSDD) and the Neuropsychiatric Inventory Nursing Home Version (NPI-NH). Data collection took place at baseline and after 8, 16 and 24 weeks. Multilevel regression models with and without false discovery rate correction were used for the analysis, with baseline values and dementia stage entered as covariates. Results Sixty-nine patients were included in the study at baseline. Compared to the control group, the intervention group had a larger reduction on the composite scores of both the CSDD (95% CI = − 6.0 – − 0.3) and the NPI-NH (95% CI = − 2.2 – − 0.1), as well as on the NPI-NH Affect sub-syndrome, and the CSDD Mood related signs sub-scale at follow-up after 16 weeks. With FDR correction, the group difference was significant on the CSDD Mood related signs sub-scale (95% CI = − 2.7 – − 0.8) and the NPI-NH Affect sub-syndrome (95% CI = − 1.6 – − 0.2). No differences were found between conditions at weeks 8 or 24. Conclusion Compared to the control condition, affective symptoms were reduced after 16 weeks in the group receiving BLT, suggesting BLT may be beneficial for nursing home patients with dementia. Trial registration ClinicalTrials.gov Identifier: NCT03357328. Retrospectively registered on November 29, 2017.

The Effect of Bright Light Treatment on Rest–Activity Rhythms in People with Dementia: A 24-Week Cluster Randomized Controlled Trial

“…We have previously reported that traditional sleep parameters, as measured by actigraphs, were not improved by the current trial [ 78 ]. However, previous publications based on data from the current trial found a positive effect of BLT in terms of proxy-rated sleep [ 78 ] and depressive symptoms [ 79 ]. While reporting biases may play a role regarding the discrepancies between objective and subjective findings, it cannot be ruled out that actigraphy is not optimal for detecting treatment response in individuals who are largely sedentary and whose daily activity rhythms are influenced by nursing home routines.…”

Phototherapy improves cognitive function in dementia: A systematic review and meta‐analysis

“…The mean age of these patients ranged from 73.73 to 85.9 years old. Four studies (Cremascoli et al, 2021;Figueir et al, 2019;Kolberg et al, 2021;Nowak, 2008) used the DSM-IV or DSM-V…”

Research advances in the study of sleep disorders, circadian rhythm disturbances and Alzheimer’s disease

“…The wavelength, dose and optimal timing of light therapy are closely related to its therapeutic effect ( Shirani and St, 2009 ). In a 24-week cluster randomized trial, the effect of BLT on the emotion of dementia patients was greater than that of the control group after 16 weeks, suggesting that BLT may be beneficial to dementia patients ( Kolberg et al, 2021 ). However, a new systematic review of the application of BLT in elderly patients with cognitive impairment shows that while BLT improves the management of sleep, behavioral and emotional disorders in patients with cognitive impairment, its impact on cognition, quality of life and functional status is limited ( Cibeira et al, 2020 ).…”