Sleep deprivation amongst adolescents is epidemic.
A child who was in the past an early riser transforms into a night owl adolescent who
stays awake until late and often needs to be woken up in the morning, especially during school days
Society tends to blame them for this; however, neuroscience has a different perspective.
There are two main mechanisms that regulate sleep: sleep-wake homeostasis and the circadian rhythm.
The sleep-wake homeostasis is the propensity of our body to chemically build a pressure
to sleep throughout the day and a pressure to wake during the night.
Therefore, the more time we are awake, the greater the pressure to fall asleep is and
the more time we are asleep, the greater the pressure to wake up.
The circadian rhythm is the biological version of a clock inside our bodies and the suprachiasmatic
nucleus, situated in the hypothalamus in the brain, is this master pacemaker.
This pacemaker adjusts our body to the 24h light/dark cycle we live in, thanks to the
electrical signals it receives from the retina in the eye.
In the retina, there are receptors which are especially sensitive to light.
At night, the suprachiasmatic nucleus induces the release of melatonin, which makes us sleepy,
and during the day, it suppresses its release which makes us feel awake.
The circadian rhythm is the main mechanism controlling sleep and it’s independent of
the number of hours we have been awake or asleep.
However, these two mechanisms work in harmony with each other to facilitate an adequate
rest and can be partially influenced by the demands of the adolescent life.
Adolescence is a period marked by an increase of social activities with peers, academic
demands, extracurricular activities and an abuse of social media and electronic devices.
Coping with all of this while sleeping the 9 hours that adolescents need is a real challenge.
These demands involve a greater exposure to light, confusing our internal clock which
delays the sleep onset to adjust to the external world.
However, evidence shows that these social factors fail to completely account for this delay.
Adolescents seem to have a slower accumulation of sleep pressure after sleep deprivation
and an internal clock more sensitive to light.
Hormonal changes during puberty seem to contribute a great deal on this, reflecting a developing
homeostatic and circadian system, which are delayed between 1 and 2 hours.
Interestingly, these changes are observed across cultures and in other mammals such
as juvenile rats, mice and macaques.
The delay starts earlier in females as these tend to sexually mature before than males
and is greater in older adolescents compared to younger adolescents.
Moreover, the delay is not present in animals that have their gonads removed before puberty.
Making an adolescent wake up at 7am to go to school or University is like forcing an
adult to wake up at 5am.
At night, circadian rhythms prepare our body to function during the day by slowly increasing
body temperature, blood pressure and releasing cortisol to increase our alertness.
At 5am none of these steps have started.
Our body is simply not ready to function and cope with society demands.
Sleep deprivation can’t be compensated and has been linked to many health issues such
as anxiety, depression, diabetes and heart disease amongst others.
Lack of sleep has also a negative impact in attention, learning and memory, and it has
been linked to lower grades.
Research has shown that delaying the starting time at school to 10am has a positive impact
in health, happiness and academic results.
Universities such as Oxford and Harvard are encouraging schools to implement this starting time.
Many are already following the example, including University College London, and this video
aims to increase awareness; after all, our teenagers are our future, let’s help them
have a healthy one.