While winter comes with a natural beauty of its own, the low levels of sunlight available also cause gloominess in many. Less exposure to sunshine can trigger chemical changes in the brain, causing fatigue, seasonal depression, social withdrawal and sleep issues. If the person is facing a neurological condition like Alzheimer’s, the issues can be exacerbated.
Science has found that light therapy or photobiomodulation, or exposing one to special light radiations that replicate sunlight, can reduce symptoms of seasonal depression and sleep issues. Phototherapy or photobiomodulation is a non-pharmacological approach that stimulates the suprachiasmatic nucleus, a sleep-regulating region in the brain.
Touching sleep and anxiety issues
A recent study published in the journal PLOS ONE reports that this form of light therapy has far more potential. It can help in improving sleep and behavioural symptoms in people with Alzheimer’s disease.
In Alzheimer’s disease, cognitive decline often manifests as sleep disruptions and psycho-behavioural symptoms such as apathy, depression, agitation, and aggression.
“Light therapy improves sleep and psycho-behavioural symptoms in patients with Alzheimer’s disease and has relatively few side effects, suggesting that it may be a promising treatment option for people with Alzheimer’s disease,” authors of the study, from Qinghui Meng of Weifang Medical University, China say in a statement.
Tried on nearly 600 people
The study was a meta-analysis of multiple research databases. For this, the team identified all controlled trials linked to light therapy interventions for Alzheimer’s disease or dementia. They also included people with sleep problems in their studies.
The researchers of the study conducted a review to understand the effect of light therapy on sleep and rhythm disturbances in people with Alzheimer’s disease. For this, they selected 15 high-quality trials. These trials were published between 2005 and 2022 and spanned seven countries, with a total of 598 people with Alzheimer’s disease undergoing light therapy.
They ensured that these trials met stringent criteria such as age, light sensitivity, stage of Alzheimer’s and intensity of light therapy and their relevant outcomes.
The researchers also ruled out trials with people who regularly use valium, anti-anxiety medicine, antidepressants or sleeping pills and people with other neurological disorders such as Parkinson’s disease, intellectual disability or eye conditions such as glaucoma, blindness and cataract.
The broad spectrum
Their trials revealed that light therapy was very effective in enhancing sleep, bolstering the strength of circadian rhythms or ‘inter-daily stability’ in the participants. In addition, they also saw a decrease in ‘intraday variability’ or frequency of transitions between rest and activity through a day.
The researchers found that light therapy not only improved the circadian rhythm in people with Alzheimer’s disease but it also reduced depression and agitation, thereby reducing the burden on caregivers.
With these preliminary positive outcomes from restricted sample sizes, the researchers want to scale up the analysis. Moreover, they plan to rule out any adverse outcomes of bright light exposure before establishing light therapy as an option for sleep and behavioural Alzheimer’s symptoms.
