Sleep-wake schedule disorder

Sleep-Wake Schedule Disorder (SWSD), also known as Circadian Rhythm Sleep Disorder, is a type of circadian rhythm sleep disorder that affects the timing of sleep, peak period of alertness, the core body temperature rhythm, hormonal and other daily cycles. People with SWSD find it difficult to sleep and wake at the times required for normal work, school, and social needs. SWSD is characterized by a misalignment between the individual's sleep pattern and the sleep pattern that is expected or desired. This disorder can lead to significant psychological, social, and functional impairments.

Causes

SWSD can be caused by various factors, including shift work, time zone changes (jet lag), medical conditions, medications, changes in routine, and disorders that disrupt the circadian rhythm. The human body has an internal clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus, which regulates the circadian rhythm. When this internal clock is disrupted, it can lead to SWSD.

Symptoms

Common symptoms of SWSD include difficulty falling asleep, difficulty staying asleep, excessive daytime sleepiness, and a general feeling of not being rested upon waking. Individuals may also experience impaired social and occupational functioning, mood disturbances, and a decreased quality of life.

Diagnosis

Diagnosis of SWSD typically involves a thorough medical and sleep history, including a sleep diary or log. In some cases, actigraphy (a wrist-worn device that measures movement) and polysomnography (a sleep study) may be used to assess sleep patterns and rule out other sleep disorders.

Treatment

Treatment for SWSD may include lifestyle and behavioral changes, light therapy, and, in some cases, medication. Lifestyle and behavioral changes can include maintaining a regular sleep schedule, avoiding caffeine and alcohol before bedtime, and creating a sleep-conducive environment. Light therapy involves exposure to bright light in the morning to help reset the body's internal clock. Melatonin supplements may also be used to adjust the sleep-wake cycle.

Prevention

Prevention of SWSD involves maintaining a regular sleep schedule, even on weekends and days off, and practicing good sleep hygiene. Exposure to natural light during the day and minimizing exposure to blue light from screens before bedtime can also help regulate the body's circadian rhythm.