Disorders in the circadian rhythm affect the natural sleep-wake cycle of a person due to irregularities in the circadian clock function or in changes in external schedule. An example of a disorder in the circadian rhythm is the advanced sleep phase syndrome (ASPS) wherein a person experiences sleepiness and wakefulness at abnormally early times in the evening and in the morning, respectively. Although this syndrome can occur on anyone, studies have found it to be more prevalent on the elderly.
In the previous years, ASPS was thought to be uncommon. However, this was only because individuals with ASPS do not seek medical attention, thinking that their condition is quite normal. Besides, an advanced sleep phase is not believed to have much impact on a person’s daily activities compared to the delayed sleep phase which prevents people from doing their activities such as going to school or work in a timely manner. Also, elderly patients suffering from ASPS are less likely to complain about their condition because they have fewer demands and social obligations to meet compared to the younger people.
Causes of Advanced Sleep Phase Syndrome in the Elderly
Sleep is an intricate interplay of different body processes and environmental factors; it is not controlled by the circadian system exclusively. Therefore, ASPS could be the result of an improperly functioning circadian clock or of some external and behavioral factors. Studies on the geriatric population indicated that aging itself causes alterations in a person’s sleep timing, such that older people tend to go to sleep and wake up earlier than the conventional schedule.
There are different explanations as to why older people are more prone to ASPS, and one of these explanations is related to the circadian phase. Accordingly, the elderly not only have an earlier clock time, but also an earlier overall circadian phase compared to the younger population. Behavioral and lifestyle changes that come with age can affect an elderly patient’s exposure to light, and thus may contribute to the development of ASPS. Older people are found to be less exposed to evening light, which has phase-delaying effects but are more exposed to morning light, which has phase-advancing effects.
Treatment of Advanced Sleep Phase Syndrome in the Elderly
The American Academy of Sleep Medicine recommended the following treatments for ASPS in elderly patients: chronotherapy, melatonin medications, and timed light exposure. The main goal of these treatment procedures is to correct the advanced sleep phase by employing phase delaying processes.
- Chronotherapy – Most elderly patients with ASPS agree that it is much easier to correct the abnormally early sleep phase by advancing their sleep schedule than by delaying it for a few hours. Sleep specialists apply chronotherapy by implementing advances of 3 hours every 2 days for 2 weeks. However, this is not applicable to all patients since this procedure is quite disruptive on the patient’s sleeping pattern.
- Melatonin – This hormone has been determined to be very effective in delaying sleep phases in humans. The administration of 0.5 to 10 mg of melatonin during the early hours of the morning, upon the awakening of ASPS patients, is found to produce optimal results. And, to avoid counteracting its phase-delaying effects, it is important to minimize light exposure.
- Light –Exposure to morning light must be minimized and exposure to evening must be maximized in order to successfully correct the abnormally early sleep phase. Patients are recommended to stay in a dimly-lit room during the early morning and in a brightly-lit room in the evening. Research suggests the use of blue-colored light bulbs in rooms of ASPS patients because the circadian photoreceptor is most sensitive at 480 nm, the wavelength of the color blue.
