Bright Light Therapy in Older Adults With Moderate to Very Severe Dementia

INTRODUCTION: Bright light therapy (BLT) has demonstrated positive effects on sleep, mood, and behavioral problems in older adults with dementia. However, there is little research in people with advanced stages of dementia.

OBJECTIVES: Main objectives are to study the immediate effects, short and long-term effects of BLT in a sample of institutionalized older adults with moderate to very severe dementia. Later, to compare the potential effectiveness of bright light therapy sessions with other non-pharmacological interventions in people with dementia.

METHODS AND ANALYSIS: The study was a 2 x 2 randomized controlled trial using a two-group design (BLT vs. control) and two repeated measures (pre- vs. postintervention). In addition, the BLT group participants were assessed immediately before, after, and during each session. The BLT protocol consisted of 30-minute morning sessions of 10,000 lux, Monday through Friday, for 4 weeks.

For the statistical analysis, two-way analysis of variance (ANOVA) are used to determine the existence of differences at two points in time (pre- vs. post-). The Wilcoxon signed-rank test or the Paired t test are used to measure changes from before to after the intervention sessions.

INTRODUCTION: Dementia is one of the main causes of disability and dependence among older adults worldwide, constituting a public health priority due to its significant human and financial costs to society. Pharmacological and non-pharmacological interventions have been proposed for the management of its clinical manifestations. The nonpharmacological interventions, which include bright light therapy (BLT), are recommended by numerous guidelines as initial treatment strategies due to the absence of adverse events. BLT consists of the controlled application of certain levels of light that can be administered in several ways. There is some evidence that effective doses of light would stimulate circadian cycles, thus affecting sleep efficiency, depression, or behavioral problems in older adults with dementia, but there is little research on persons in advanced stages of dementia.

The lack of consensus on the protocol for BLT application, as well as the existence of little research on individuals in advanced stages of dementia, calls for further research to explore in-depth the immediate, short- and long-term effects of BLT in this population.

OBJECTIVES: Main objectives were: (1) to study the short- and long-term effects of bright light therapy on mood, behavior, sleep, and cognition in a sample of institutionalized older adults with moderate to very severe dementia; (2) to explore the immediate effects of bright light therapy sessions on behavior, mood and physiological parameters in a sample of institutionalized older adults with moderate to very severe dementia; and (3) to compare the effectiveness of bright light therapy sessions with other non-pharmacological interventions in people with dementia.

METHODS: This longitudinal, comparative and prospective study, is a 2 x 2 randomized controlled trial using a two-group design (BLT vs. control) and two repeated measures (pre- vs. postintervention). In addition, the BLT group participants were assessed immediately before, after, and during each session. Participants were recruited among residents of the Gerontological Complex La Milagrosa (A Coruña, Spain). The BLT protocol consisted of 30-minute morning sessions in the time slot between 10:30 and 12:00, 5 days a week (Monday to Friday), for 4 weeks (total 20 sessions). The devices used for the intervention were bright white light lamps providing an intensity of 10,000 lux. Four users participated in each session, placing two users per lamp, seated 70 cm from the lamp. All data analysis will be performed with the statistical programs SPSS- Statistical Package for the Social Sciences (version 25.0), RStudio software package (Version 1.3.1093), and JAMOVI (The jamovi project, 2020, Version 1.2).

Eligibility Criteria:
Inclusion Criteria:

* age 65 years or older
* diagnosis of dementia
* a score ≥ 4 points on the Global Deterioration Scale (GDS; Reisberg et al., 1982), ranging from moderate to very severe cognitive decline.

Exclusion Criteria:

* high ocular sensitivity to light (photosensitivity)
* preexisting ocular abnormalities
* having any severe ocular disorder that did not allow them to open their eyes or that implied a very low visual acuity.