Monday, September 25, 2023
Do 1-hour naps help or hurt? Most patients think that short naps do help.
Professor of Psychiatry, Jefferson Medical College, Philadelphia, Pennsylvania; Director, Sleep Disorders Center, Thomas Jefferson University, Philadelphia, Pennsylvania
Napping is a common human phenomenon. In one study of young and middle-aged adults, approximately 74% reported napping during the course of a week, with half reporting an average nap length of 20 minutes. Nappers did not have impaired sleep when compared with non-nappers.[1] Spontaneous napping is based on a normal, bimodal, circadian pattern of sleepiness, whereby sleepiness peaks at night and midafternoon.[2] Therefore, the siesta is quite common in many cultures. Despite its ubiquity, some studies of large population samples have shown that napping is associated with various impairments and even increased mortality.[3] Such data are difficult to interpret because they indicate associations that may not necessarily imply causality.
In sleepy populations, naps as brief as 15 minutes are followed by improved daytime functioning. One study of narcolepsy patients and sleep-deprived normal subjects also showed that extending nap lengths to 2 hours provided even greater benefit.[4] In a study of medical residents engaged in shift work in an emergency department, the opportunity to nap for approximately 1 hour was associated with an increase in vigilance as measured by electroencephalography, although subsequent performance remained unchanged.[5] Although the utility of naps in other populations has not been well investigated, such data indicate that naps can have important therapeutic value in individuals in whom high levels of sleepiness impair performance and may even lead to falling asleep in dangerous situations. It is prudent, however, to limit naps to an hour or so, because clinical wisdom suggests that lengthy naps, when taken on a consistent basis, may threaten to alter circadian sleep-wake patterns and result in a disruption of nocturnal sleep.
In contrast, in insomnia populations, the avoidance of naps has been proposed as a method of enhancing sleep continuity on the following night.[6] Additionally, excessive napping may be indicative of an underlying sleep disorder, such as obstructive sleep apnea syndrome. Some depressed patients also spend lengthy times in bed during the day, although they do not necessarily sleep during this time. Therefore, in clinical settings, the need for excessive times in bed should be carefully explored and any underlying causes should be identified.
