Advanced sleep phase disorder

A circadian rhythm sleep disorder characterized by early sleep and wake times

Advanced sleep phase disorder (ASPD) is a circadian rhythm sleep disorder characterized by a significant advancement of the major sleep episode in relation to the desired or conventional sleep time and wake-up time. Individuals with ASPD typically fall asleep in the early evening and wake up in the early morning, often several hours earlier than the societal norm.

Pathophysiology

The underlying mechanism of ASPD involves the circadian clock, which is located in the suprachiasmatic nucleus (SCN) of the hypothalamus. In individuals with ASPD, the circadian clock is advanced, leading to earlier sleep and wake times. This condition is thought to be influenced by genetic factors, as it often runs in families.

Symptoms

The primary symptom of ASPD is the inability to stay awake until the desired bedtime, leading to early sleep onset. Consequently, individuals with ASPD wake up very early in the morning, often before they wish to. This can result in sleep deprivation if the individual attempts to conform to a later sleep schedule.

Diagnosis

Diagnosis of ASPD is typically made through a combination of patient history, sleep diaries, and polysomnography or actigraphy. A sleep study may be conducted to rule out other sleep disorders. The use of melatonin levels and core body temperature measurements can also aid in diagnosing circadian rhythm disorders.

Treatment

Treatment for ASPD may include chronotherapy, which involves gradually delaying sleep time to a more conventional schedule. Light therapy in the evening can help delay the circadian clock, while melatonin administration in the morning can reinforce the delay. Behavioral interventions, such as maintaining a consistent sleep schedule and avoiding bright light in the morning, are also recommended.

Prognosis

The prognosis for individuals with ASPD varies. Some may adapt to their early schedule, while others may experience social and occupational difficulties due to misalignment with societal norms. Treatment can help align sleep patterns with desired schedules, improving quality of life.

Related pages

• Circadian rhythm sleep disorder
• Delayed sleep phase disorder
• Non-24-hour sleep–wake disorder
• Irregular sleep–wake rhythm disorder

Gallery

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  Sleep studies are often used to diagnose sleep disorders.

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  Diagram of the circadian clock in mammals.

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  Advanced sleep phase disorder

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  Circadian clock of mammals