Light Therapy a Beacon of Hope for Alzheimer’s?

TOPLINE:

Light therapy leads to significant improvement in several sleep measures and helps alleviate depression and agitation in patients with Alzheimer’s disease (AD), a meta-analysis of 15 high-quality trials shows.
METHODOLOGY:

• This meta-analysis included 15 randomized controlled trials involving 598 patients with mild to moderate AD.
• The included trials were written in English, published between 2005 and 2022, and performed in seven countries. A fixed-effects model was used for data analysis.

TAKEAWAY:

• Light therapy significantly improved sleep efficiency (mean difference [MD], −2.42; P < .00001), increased interdaily stability (MD, −0.04; P < .00001), and reduced intradaily variability (MD, −0.04; P < .00001), indicating better sleep quality.
• Light therapy reduced agitation (MD, −3.97; P < .00001), depression (MD, −2.55; P < .00001), and caregiver burden (MD, −3.57; P < .00001).
• Light therapy also had a significant advantage over usual care in reducing the severity of psychobehavioral symptoms as assessed by the Neuropsychiatric Inventory (MD, −3.07; P < .00001).
• Light therapy had no statistically significant effect on improving cognitive function as measured by the Mini-Mental State Examination.

IN PRACTICE:

“These findings, combined with its low side-effects, suggest the role of light therapy as a promising treatment for AD. Although light therapy has fewer side effects than pharmacological treatment, adverse behavioral outcomes in patients due to bright light exposure should be considered,” the authors write.
SOURCE:

The study by Lili Zang and colleagues from Weifang Medical University School of Nursing, Shandong Province, China, was published online on December 6, 2023, in PLOS One.
LIMITATIONS:

The types and degrees of dementia in the included studies were inconsistent, potentially affecting the outcome indicators. Some articles did not clearly describe their randomization and allocation concealment methods, indicating possible bias in these studies.
DISCLOSURES:

The study was supported by the Natural Science Foundation of Shandong Province, China. The authors declared no competing interests.