The perfect hurricane in Latin America: school start time, chronotype, sleep, and academic performance during adolescence

Abstract

Circadian rhythms are modulated by age. The timing of the circadian clock under real-life conditions (i.e., chronotype) is progressively delayed during adolescence. However, schools start very early in the morning, when the adolescent’ clock is still not prepared to be awake. Consistently, the misalignment between early school timing and late chronotypes leads to poor sleep: both short and out-of-time, which is associated with adverse consequences for health and cognitive and academic performance. This situation worsens in some countries due to cultural differences: Argentinian adolescents have even later chronotypes than most of their peers around the globe. Later school start times are associated with better sleep and a lower impact of chronotype on academic performance. Several strategies are suggested to evaluate and to mitigate the consequences of the misalignment between chronotype and school timing. Importantly, local studies and interventions are the key to understand and improve adolescents’ education and well-being.