Bright light therapy is a treatment that has been used in patients with disruptions in their circadian rhythms. This is the internal biological clock that tells the brain and body when it should be awake and when it should sleep. There are several factors that could disrupt this rhythm, including chronic disease, travel, stress, and light pollution.
Recent studies published in Psychogeriatrics and JAMA Neurology have found that bright light therapy (BLT) may be helpful in some debilitating chronic diseases like dementia, Alzheimer’s, and Parkinson’s disease, which are notorious for negatively affecting sleep patterns in sufferers.
For the most part, hypnotic drugs are used to help with sleep, but side effects can be extremely troublesome for patients who are already cognitively and neurologically compromised. Dementia and Parkinson’s patients react badly to sleep drugs because of the daytime sleepiness, amnesia, and additional fall risks.
Therefore, bright light therapy was trialed first in Alzheimer’s and dementia patients, and then in Parkinson’s patients.
Daytime administration of BLT was helpful for dementia patients because it retrained the circadian rhythm to override the disturbances; however, as with all studies, researchers noted some limitations and issues.
They did not adjust findings to types or grades of dementia, and there is no set protocol for BLT administration yet. In the study of dementia and Alzheimer’s patients, 17 participants were given BLT for one hour a day in the morning for a total of two weeks. Four of the 17 patients showed marked improvement in their sleep quality, all of whom had Alzheimer’s type dementia. These patients were still in earlier stages of the disease. This indicates that BLT could be an effective preventive measure for Alzheimer’s patients, depending on type and grade.
Parkinson’s disease patients have limited options to treat their sleep problems as well. As noted in the study published in JAMA Neurology from Northwestern and Rush Universities, bright light therapy showed significant improvement in daytime sleepiness for these patients, per results on the Epworth Sleepiness Scale; however, dim-red light therapy also showed some improvements in sleep quality.
A total of 31 patients participated in this Parkinson’s study, which was randomized and placebo-controlled. Patients were split into two groups: one group received bright light therapy and the other received dim-red light therapy for one hour a day over the course of two weeks.
Patients who received BLT reported improvement in sleep metrics like reduced number of nighttime awakenings and the ability to fall asleep faster. Both forms of light therapy showed increases in physical activity.
Light therapy is a non-invasive or pharmaceutical intervention that is well-tolerated. It may prove to be a good intervention for chronic disease patients with disrupted sleep-wake cycles. As with all scientific findings, further research with larger and more diverse patient populations would be beneficial in determining the efficacy of bright light therapy for sleep disturbance.
Rachael Herman is a professional writer with an extensive background in medical writing, research, and language development. Her hobbies include reading, traveling, and cooking.
© 2021 American Sleep Association.