Prescribed sleep/wake scheduling Experts agree that there is no such thing as an "ideal" night<unk>  schedule, but some schedules may be better than others. For example, rotating<unk> s every two weeks in a forward (delaying) direction was found to be easier than rotation in a backward (advancing) direction. Gradual delays (“nudging” the circadian system about an hour per day) has been shown in a laboratory setting to maintain synchrony between sleep and the endogenous circadian rhythms, but this schedule is impractical for most real world settings. Some experts have advocated short runs (1 to 2 days) of night<unk>  with time for recovery; however, in the traditional heavy industries, longer (5 to 7 day) runs remain the rule. In the end, scheduling decisions usually involve maximizing leisure time, fairness in labor relations, etc. rather than chronobiological considerations.<unk> <unk> ers can benefit from adhering to sleep hygiene practices related to sleep/wake scheduling. Symptoms typically only fully resolve once a normal sleep schedule is resumed. Many night<unk> ers take naps during their breaks, and in some industries, planned napping at<unk>  (with facilities provided) is beginning to be accepted. A nap before starting a night<unk>  is a logical prophylactic measure. However, naps that are too long (over 30 minutes) may generate sleep inertia, a groggy feeling after awakening that can impair performance. Therefore, brief naps (10 to 30 minutes) are preferred to longer naps (over 30 minutes). Also, long naps may interfere with the main sleep period. In the transportation industry, safety is a major concern, and mandated hours of service rules attempt to enforce rest times. Bright light treatment The light-dark cycle is the most important environmental time cue for entraining circadian rhythms of most species, including humans, and bright artificial light exposure has been developed as a method to improve circadian adaptation in night<unk> ers. The timing of bright light exposure is critical for its phase<unk> ing effects. To maximize a delay of the body clock, bright light exposure should occur in the evening or first part of the night, and bright light should be avoided in the morning. Wearing dark goggles (avoiding bright light) or blue-blocking goggles during the morning commute home from<unk>  can improve circadian adaptation. For<unk> ers who want to use bright light therapy, appropriate fixtures of the type used to treat winter depression are readily available but patients need to be educated regarding their appropriate use, especially the issue of timing. Bright light treatment is not recommended for patients with light sensitivity or ocular disease. Melatonin treatment Melatonin is a hormone secreted by the pineal gland in darkness, normally at night. Its production is suppressed by light exposure, principally blue light around 460 to 480 nm. Light restriction, or dark therapy, in the hours before bedtime allows its production. Dark therapy does not require total darkness. Amber or orange colored goggles eliminate blue light to the eyes while allowing vision. Melatonin is also available as an oral supplement. In the US and Canada, the hormone melatonin is not classified as a drug; it is sold as a dietary supplement. In other countries, it requires a prescription or is unavailable. Although it is not licensed by the FDA as a treatment for any disorder, there have been no serious side effects or complications reported to date. Melatonin has been shown to accelerate the adaptation of the circadian system to a nighttime<unk>  schedule. Melatonin may benefit daytime sleep in night<unk> ers by an additional direct sleep promoting mechanism. Melatonin treatment may increase sleep length during both daytime and nighttime sleep in night<unk> <unk> ers. Medications that promote alertness Caffeine is the most widely used alerting drug in the world and has been shown to improve alertness in simulated night<unk> . Caffeine and naps before a night<unk>  reduces sleepiness during the<unk> . Night<unk>  medical field<unk> ers report the highest activity, along with the least amount of sleep. These individuals require medication/power naps to function at their best. Modafinil and armodafinil are non-amphetamine alerting drugs originally developed for the treatment of narcolepsy that have been approved by the FDA (the US Food and Drug Administration) for excessive sleepiness associated with SWSD. Medications that promote daytime sleep Obtaining enough sleep during the day is a major problem for many night<unk> ers. Hypnotics given in the morning can lengthen daytime sleep; however, some studies have shown that nighttime sleepiness may be unaffected. Zopiclone has been shown to be ineffective in increasing sleep in<unk> <unk> ers.
Shift work sleep disorder
Circadian rhythm sleep disorder
Central sleep apnea
Sleep apnea
Sleep disorder
Sleep deprivation
Obstructive sleep apnea
Sleep-related breathing disorder