Quite the opposite, they sleep more the than normal.
Actually, according to my nursing textbooks, depression can manifest either by sleeping more or less than usual. So five hours of sleep a night could, for some people, be a symptom of depression. And I do remember reading somewhere about first-year college or university students developing clinical depression after a few months of unaccustomed stress and lack of sleep. And for most university students, it probably takes willpower to go to bed early, since nearly everyone I know who is my age seems to be on a longer-than-24-hour natural sleep schedule. So lack of sleep could cause depression, although once you were depressed, you might find yourself wanting to sleep more (and having an even harder time keeping up with classes).
Personal anecdote: long periods of sleep deprivation can mess up your neurotransmitter levels enough to cause an episode of psychosis. This actually happened to one of my good friends. (When you’re waking up at 4:30 am every day for swim practice, and staying up late for whatever reason including just wanting to have a life, sleep deprivation can very quickly get out of hand.) You probably have to be genetically predisposed, but still...it scares me.
And for most university students, it probably takes willpower to go to bed early, since nearly everyone I know who is my age seems to be on a longer-than-24-hour natural sleep schedule.
It seems likely that this is a combination of youthful endurance plus a lack of night cues (computer screens make fake-sunlight at any time of the night), rather than young people actually having a circadian rhythm that’s longer by hours.
That it is not a mere preference but a biological reality is one of the reasons I regard melatonin as so useful—fight fire with fire.
EDIT: Of course, it’s also true that artificial light and computer screens are not helpful in the least: see the second paragraph in http://www.gwern.net/Melatonin#health-performance So you might say for young people, it’s a many-edged problem: they naturally want to go to bed late, their electronic devices exacerbate the original biological problem, and then all the social dynamics can begin to contribute their share of the problem...
I think Vaniver is objecting to the narrow claim of a cycle longer than 24 hours. Without clicking through on your sources, they seem to say that teens have a shifted cycle, not a longer cycle.
In particular, that shifting school later improves sleep suggests that teens have a shifted cycle. If they had an unmoored cycle of longer than 24 hours, the greater light exposure of an earlier start would probably be better.
Douglas_Knight is correct; I’m not challenging “young people want to go to bed late and get up late” but “young people want to sleep six times a week rather than seven” (or, more reasonably, 13 times every two weeks).
I do remember reading in a variety of places that young people, especially teenagers, tend to have more trouble sticking to an earlier sleep schedule. But you’re right that this isn’t necessarily biological in origin. It could just be that young people have a) greater benefits to gain from staying up late, since that’s when a lot of socializing takes place, and b) less practice using willpower to force themselves to go to bed, and maybe less incentive, since with their “youthful endurance” they can push through on 2-3 hour of sleep.
And being able to do this, or for example get really drunk and still make it to work early the next morning, is definitely a status thing that people are almost competitive about. Maybe some kind of signalling at work, too: “I’m so healthy and strong, I can afford to get really, really drunk and hardly get any sleep and still function...I must have awesome genes.” That could explain how being a compete idiot and passing out on my friend’s floor in front of my supervisor when I had an exam the next day somehow made me cooler to all the staff.
Actually, according to my nursing textbooks, depression can manifest either by sleeping more or less than usual. So five hours of sleep a night could, for some people, be a symptom of depression. And I do remember reading somewhere about first-year college or university students developing clinical depression after a few months of unaccustomed stress and lack of sleep. And for most university students, it probably takes willpower to go to bed early, since nearly everyone I know who is my age seems to be on a longer-than-24-hour natural sleep schedule. So lack of sleep could cause depression, although once you were depressed, you might find yourself wanting to sleep more (and having an even harder time keeping up with classes).
Personal anecdote: long periods of sleep deprivation can mess up your neurotransmitter levels enough to cause an episode of psychosis. This actually happened to one of my good friends. (When you’re waking up at 4:30 am every day for swim practice, and staying up late for whatever reason including just wanting to have a life, sleep deprivation can very quickly get out of hand.) You probably have to be genetically predisposed, but still...it scares me.
It seems likely that this is a combination of youthful endurance plus a lack of night cues (computer screens make fake-sunlight at any time of the night), rather than young people actually having a circadian rhythm that’s longer by hours.
I disagree. The circadian rhythms in middle school and up is very well established; please see all the links & citations in http://www.gwern.net/education-is-not-about-learning#school-hours
That it is not a mere preference but a biological reality is one of the reasons I regard melatonin as so useful—fight fire with fire.
EDIT: Of course, it’s also true that artificial light and computer screens are not helpful in the least: see the second paragraph in http://www.gwern.net/Melatonin#health-performance So you might say for young people, it’s a many-edged problem: they naturally want to go to bed late, their electronic devices exacerbate the original biological problem, and then all the social dynamics can begin to contribute their share of the problem...
I think Vaniver is objecting to the narrow claim of a cycle longer than 24 hours. Without clicking through on your sources, they seem to say that teens have a shifted cycle, not a longer cycle.
In particular, that shifting school later improves sleep suggests that teens have a shifted cycle. If they had an unmoored cycle of longer than 24 hours, the greater light exposure of an earlier start would probably be better.
Douglas_Knight is correct; I’m not challenging “young people want to go to bed late and get up late” but “young people want to sleep six times a week rather than seven” (or, more reasonably, 13 times every two weeks).
I do remember reading in a variety of places that young people, especially teenagers, tend to have more trouble sticking to an earlier sleep schedule. But you’re right that this isn’t necessarily biological in origin. It could just be that young people have a) greater benefits to gain from staying up late, since that’s when a lot of socializing takes place, and b) less practice using willpower to force themselves to go to bed, and maybe less incentive, since with their “youthful endurance” they can push through on 2-3 hour of sleep.
And being able to do this, or for example get really drunk and still make it to work early the next morning, is definitely a status thing that people are almost competitive about. Maybe some kind of signalling at work, too: “I’m so healthy and strong, I can afford to get really, really drunk and hardly get any sleep and still function...I must have awesome genes.” That could explain how being a compete idiot and passing out on my friend’s floor in front of my supervisor when I had an exam the next day somehow made me cooler to all the staff.