Sleep Patterns in the Transition from Adolescence toYoung Adulthood Antonio Vela-Bueno, MD*, Julio Fernandez-Mendoza, PsyD , Sara Olavarrieta-Bernardino, PsyD The transition between adolescence and adult- hood takes place between 18 and 25 years, with different authors identifying varying ranges of age. 1 Factors that may contribute to prolonging (eg, graduate education) or to shortening (eg, early marriage) this duration may contribute to that variability. Generally speaking, despite the relevant matu- rational and developmental changes that take place during this transitional period, this period of life has received relatively little attention com- pared with childhood or adolescence. 2 Sleep and sleep-related health issues in this period of life also have received relatively little attention, despite the presence of sleep complaints and disorders. 3 A recent review article on the health status of young adults (age 18–24 years) in the United States completely ignored sleep. 4 It included alcohol as a causative factor in driving accidents, but it did not mention sleep, although sleep-related crashes are common in this population. For example, in a study in North Carolina, 5 55% of motor vehicle accidents that re- sulted from the driver’s falling asleep at the wheel (a common manifestation of daytime sleepiness) involved people 25 years of age or younger, with the peak age of occurrence being 20 years of age. Developmental changes, rather than matura- tional ones, seem to have an important role in some of the main sleep complaints in this period of life. These complaints include disturbances of the sleep–wakefulness circadian rhythm, insuffi- cient sleep, and the resulting excessive daytime sleepiness. This article first reviews the developmental and maturational changes associated with normal and disturbed sleep and continues with a review of the epidemiologic data on sleep complaints and disorders during the transition from adoles- cence to adulthood. The existing data come mainly from college student populations. The last section makes some recommendations for prevention of and coping with sleep disturbances. MATURATIONAL AND DEVELOPMENTAL CHANGES In the late years of adolescence and in the early years of adulthood some maturational processes are still being completed, whereas a slow decline of some functions starts to occur in young adults even in their early 20s. 2 Generally speaking, there is some overlap between progression and regres- sion in the transition from adolescence to adulthood. The sleep pattern of young adults has been used as a template to assess the changes in sleep along the life cycle. 6 Nevertheless a more nuanced description of sleep patterns in more specific age subgroups of young adulthood, including the tran- sition between adolescence and adulthood, is lacking. Human Sleep and Applied Chronobiology Laboratory, Department of Psychiatry, Universidad Autonoma de Madrid, c/Arzobispo Morcillo, 4, 28029 Madrid, Spain * Corresponding author. E-mail address: antonio.vela@uam.es (A. Vela-Bueno). KEYWORDS  Young adults  Sleep habits  Sleepiness  Sleep disorders  Academic performance Sleep Med Clin 4 (2009) 77–85 doi:10.1016/j.jsmc.2008.12.003 1556-407X/08/$ – see front matter ª 2009 Elsevier Inc. All rights reserved. sleep.theclinics.com