Sleep-wake schedule disorders

The final category is termed the sleep-wake schedule disorders. These are seen in people who get their days and nights turned around. The most common examples are shift workers and travelers with jet lag. Additionally, in the elderly, especially those with dementia, a malfunction in the circadian biological rhythm that regulates sleep can leave them awake and alert at night but drowsy and sleeping during the day. 

Transient disturbances may occur as a result of rapid time zone changes (as in transoceanic flights) or staying up late for a few days. Diagnosis of a sleep— wake schedule disorder, however, is made only if complaints meet criteria for an insomnia or a hypersomnia disorder. These disorders often improve when the person is able to resume a normal sleep—wake pattern. 

Moreover, there is evidence for increased rates of ADHD symptoms in clinical populations of children with sleep disorders, including children with the obstructive sleep apnea syndrome (OSAS), periodic limb movements of sleep (PLMS), narcolepsy, and sleep-wake schedule disorders. Studies indicate that treating the primary sleep disorder can produce significant improvement in ADHD symptoms (103). 

Until the mid 90s, no study demonstrated the main factors responsible for sleep-related accidents. We questioned, apart from organic sleep disorders, whether modifications of the sleep-wake schedules could be responsible for sleepiness at the wheel. Studying large populations of drivers (22,23), we demonstrated that long-distance driving was frequently associated with sleep curtailment. Our first study (22), performed on a freeway rest stop area in 1993, showed that 50% of drivers (n = 567 drivers) reduced their sleep duration in the 24 hr before departure for a long-distance journey. Ten percent of drivers had no sleep in the 24 hr before the interview. These stunning results could have been explained by a... 

The sleep disorders fall into four main categories (1) insomnia, (2) hypersomnia, (3) parasomnias, and (4) sleep schedule disorders. Insomnia is the most common sleep problem. It is simply defined as poor sleep and can be manifested by difficulty falling asleep, difficulty staying asleep, waking up too early, or waking up in the morning without feeling refreshed. 

This disorder occurs when there is a mismatch between the normal rest—activity schedule for a person s environment and the person s circadian sleep— wake pattern. There are four subtypes ... 

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