There's been a lot of research about the adolescent body clock and it's now well understood that it's the hormonal upsets of puberty that are fully to blame - as always.
Specifically, it's melatonin that's responsible for a reset of their body clock, causing teenagers to fall asleep later and to wake later. Melatonin helps us sleep and its increase in production by the pineal gland normally comes with the onset of darkness.
In a teenager there can be a delay in this happening, thus delaying their desire to sleep. Couple that with an irregular pattern of getting to bed during the week and weekend, and their normal sleep time becomes 11pm to 1am.
A teenager generally needs about 9-10 hours of sleep so it's easy to see that the numbers don't add up. As a result, come morning when the rest of the family are up and about and ready for the day, our teen still has elevated melatonin levels and can barely put one foot in front of the other, if, indeed, they've managed to get those feet out of bed and on to the floor.
Trying to get them to bed earlier is probably going to be a pointless and frustrating exercise for everyone. Either the teenager's timetable needs to be changed to fit the body's internal clock, and some schools are doing this, or you could try to gradually reset their body clock. As this requires both the teen and their hormones to co-operate, it has a mixed success rate.
Start by stabilising bedtime for several nights at the time when it's currently natural and easy to fall asleep. Then move it forward by 15 minutes and maintain it at that new time for two nights, continuing the process in 15-minute movements until the desired bedtime is achieved.
Establishing a regular and consistent wake-up time along with exposure to light is also important, so throw open those curtains. It's the wake-up time that actually controls the body clock as daylight triggers the lowering of melatonin levels.
Maintain this pattern without exception for two to three weeks. After this time, staying up late occasionally won't reset the clock but any sleep-in shouldn't be later than one or two hours after the normal get-up time for school. Good luck!
Alternatively, we can grin and bear it and assist an eventual return to more normal sleep patterns by serving meals at regular times, encouraging physical activity and having a screen-free hour for all before a regular bedtime. Although, some research suggests that it could be age 55 before we return to the sleeping patterns of our 10-year-old self!
