Original article
Chronotypes and sleep deprivation among adolescents

A growing body of evidence indicates that sleep problems are common in adolescents. Insomnia, sleep insufficiency, and daytime sleepiness are prevalent in this age group. This study was aimed to examine self-assessed sleep/wake patterns and problems among Polish adolescents. The correlation between sleep deficit and individual chronotypes was also analysed. A total of 369 girls and 202 boys, high school students aged 17-19 years, completed the survey. Sleep duration on weekdays (girls: 411 ±84 min, boys: 419 ±96 min) was significantly shorter, by approximately 2 hours, than that on weekends. Mid-sleep time differed significantly between weekdays (girls: 03:09 ±46 min, boys: 03:27 ±53 min) and weekends (girls: 05:11 ±77 min, boys: 05:33 ±83 min). The biggest differences in sleep duration and mid-sleep time were found in adolescents with evening chronotypes, while the smallest were found in subjects with morning chronotypes. In 13% of the responders Insomnia Severity Index (ISI) scores were  15. Excessive daytime sleepiness was common; 44% of girls and 30% of boys complained of having it at least once a week. 9% of the teenagers reported suffering from sleep attacks every day. The prevalence of sleep deficit and its consequences points to a need to increase awareness of this problem in the education and health care communities in order to improve sleep hygiene and reduce the negative impact of sleep deprivation among adolescents.