Introduction: A number of different studies have shown that there is a high prevalence of sleep disorders among adolescents. These are often cited as being due to psychological, hormonal or pubertal factors, as well as inadequate sleep habits.
Aims: The aims of this study were to determine the prevalence of sleep disorders in the adolescent population and to describe their sleep habits and the relationship between sleep disorders and daytime tiredness or drowsiness.
Subjects and methods: We conducted an epidemiological, observational, cross-sectional study in a sample of schoolchildren studying the 1st and 4th years of compulsory secondary education by means of a self-administered anonymous questionnaire. Insomnia was diagnosed using DSM-IV criteria.
Results: Of a total number of 1155 children, 537 were males and 618 were females, with a mean age of 14.03 +/- 1.86 years. They sleep an average of 8 h 18 m during the week and 9 h 40 m at the weekend. Poor quality sleep was reported by 38.55%, 23.1% had difficulty in getting to sleep, 38.2% woke up during the night and 15.9% woke up too early. 17.7% reported some kind of sleep complaint plus some other insomnia-related symptom; the prevalence of insomnia was found to be 9.9%. Snoring (20.5%), talking in their sleep (45.4%) and nightmares (29.5%) were the most frequent parasomnias. 53% of them complained of excessive sleepiness during the day. Insomnia is more frequent in older adolescents, with a family history of similar disorders, among those who smoke and drink and sleep fewer hours at the weekend; those with insomnia present more symptoms of anxiety and depression, as well as more daytime drowsiness.
Conclusions: A number of factors are related to the high prevalence of sleep disorders among adolescents, giving rise to their being very tired and drowsy during the day. The interruption of their normal sleep habits at the weekend and an insufficient number of hours' sleep are related to the appearance of insomnia.