Short article from the Guardian (UK) which I found interesting.
Here's the study that's the basis for the article below, with excerpt below the link. The National Sleep Foundation in the US has had 18 experts
So now we know how much sleep we need. The National Sleep Foundation in the US has had 18 experts sifting through 320 research articles to deliver an updated version of its “sleep time duration recommendations”. The articles were whittled down from an original 2,412 on the basis of the strength of the studies.
... The new guidelines not only give recommended amounts, but also state what might be appropriate for different ages. Children aged six to nine need nine to 11 hours a night, but may get by on seven to eight. Teenagers need eight to 10 hours. Seven hours may be OK for some, but sleeping more than 11 hours a day may be detrimental to their health, although some may need that much during puberty.
Dr Lydia DonCarlos from Loyola University, Chicago, one of the experts on the study, says that the circadian rhythm of teenagers naturally shifts to make them feel sleepy later at night and to wake up later. This is a normal phenomenon and nothing to do with being addicted to social media. She warns that teenagers should still try to get enough sleep on a daily basis, rather than building up a sleep debt to pay off at weekends. “You can never quite make it up,” she says.
Adults aged 18 to 64 need to sleep for seven to nine hours a night, but some cope on six. For people over the age of 65, the recommended amount is between seven and eight hours, although some survive on five hours sleep (often waking up earlier and napping during the day).