Catecholaminergic nerve fibres in normal and alkali-burned rabbit cornea

Increased lifestyle demands and reduced sleep are reported to result in daytime sleepiness and impaired functioning for teenagers. A sample of 612 freshman urban high school students completed a questionnaire describing their sleep patterns and problems, along with sociodemographic information, daily activities, pubertal development, depressive mood, and morning-evening preference. About 63% of the respondents felt they needed more sleep on weeknights (MS group), experienced sleepiness that interfered with their schoolwork, and had problems with sleeping. The other group reported they got sufficient sleep on weeknights (SS group) and did not experience sleepiness problems to the same degree. However, both had similar weeknight sleep and daily activity patterns. The MS group reported an ideal sleep time of 9.2 h, about 2 h more than they were getting and 1 h more than the SS group ideal, and had a higher preference for later bed and waking times. In our sample, individual differences in biologic sleep need and quality of sleep may be emerging as early as 14 years of age.