  Sleep disorders can be a negative factor both for learning as for the mental
and physical development of adolescents. It has been shown that, in many
populations, adolescents tend to have a poor sleep quality, and a very late
chronotype. Furthermore, these features peak at adolescence, in the sense that
adults tend to sleep better and have an earlier chronotype. But what happens
when we consider adolescents in a population where already adults have poor
sleep quality and a very late chronotype? We have conducted two non-clinical
studies in the city of Bariloche, Argentina aimed at measuring sleep quality,
chronotype, and social jet lag, using the Pittsburgh and Munich questionnaires.
These were administered individually to groups of high school students, as well
as to smaller samples of adults and preadolescents, in order to study
differences between adolescents and these groups. The results show that in this
population sleep quality is much poorer than in most other healthy populations
recorded elsewhere. Furthermore, sleep quality is consistently worse for
adolescents than for the other groups. The difference with adults seems to be
due mainly to increased daytime sleepiness and sleep latency, whereas the
difference with preadolescents seems to be due mainly to shorter sleep
duration. We also found that the chronotypes of all the groups are very late,
with a peak at an age between 18 and 24 ys. Social jet lag and sleep onset
latency are also large, and they peak at adolescence, which suggests that they
might be closely related to the large prevalence of poor sleep quality that we
find in adolescents.
