Individuals with FASPS fall asleep and wake up 4–6 hours earlier than the average population, generally sleeping from 7:30pm to 4:30am. They also have a free running circadian period of 22 hours, which is significantly shorter than the average human period of slightly over 24 hours. The shortened period associated with FASPS results in a shortened period of activity, causing earlier sleep onset and offset. This means that individuals with FASPS must delay their sleep onset and offset each day in order to entrain to the 24-hour day. On holidays and weekends, when the average persons sleep phase is delayed relative to their workday sleep phase, individuals with FASPS experience further advance in their sleep phase.Aside from the unusual timing of sleep, FASPS patients experience normal quality and quantity of sleep. Like general ASPD, this syndrome does not inherently cause negative impacts, however, sleep deprivation may be imposed by social norms causing individuals to delay sleep until a more socially acceptable time, causing them to losing sleep due to earlier-than-usual wakeup time.Another factor that distinguishes FASPS from other advanced sleep phase disorders is its strong familial tendency and life-long expression. Studies of affected lineages have found that approximately 50% of directly related family members experience the symptoms of FASPS, which is an autosomal dominant trait. Diagnosis of FASPS can be confirmed through genetic sequencing analysis by locating genetic mutations known to cause the 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 bodys central circadian clock, which is located in the suprachiasmatic nucleus in the hypothalamus. Symptoms
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. Diagnosis
Individuals expressing the above symptoms may be diagnosed with ASPD using a variety of methods and tests. Sleep specialists measure the patients 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. Treatment
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.