Advanced sleep phase disorder

Advanced Sleep Phase Disorder (ASPD), also known as the advanced sleep-phase type (ASPT) of circadian rhythm sleep disorder, is a condition that is characterized by a recurrent pattern of early evening (e.g. 7-9 PM) sleepiness and very early morning awakening (e.g. 2-4 AM). This sleep phase advancement can interfere with daily social and work schedules, and results in shortened sleep duration and excessive daytime sleepiness. The timing of sleep and melatonin levels are regulated by the body's central circadian clock, which is located in the suprachiasmatic nucleus in the hypothalamus. Individuals with ASPD report being unable to stay awake until conventional bedtime, falling asleep early in the evening, and being unable to stay asleep until their desired waking time, experiencing early morning insomnia. When someone has advanced sleep phase disorder their melatonin levels and core body temperature cycle hours earlier than an average person. These symptoms must be present and stable for a substantial period of time to be correctly diagnosed. Individuals expressing the above symptoms may be diagnosed with ASPD using a variety of methods and tests. Sleep specialists measure the patient's sleep onset and offset, dim light melatonin onset, and evaluate Horne-Ostberg morningness-eveningness questionnaire results. Sleep specialists may also conduct a polysomnography test to rule out other sleep disorders like narcolepsy. Age and family history of the patient is also taken into consideration. Once diagnosed, ASPD may be treated with bright light therapy in the evenings, or behaviorally with chronotherapy, in order to delay sleep onset and offset. The use of pharmacological approaches to treatment are less successful due to the risks of administering sleep-promoting agents early in the morning. Additional methods of treatment, like timed melatonin administration or hypnotics have been proposed, but determining their safety and efficacy will require further research.