Teenagers who go to bed late during the school term are more likely to have academic and emotional problems later on, a new study suggests.

The importance of getting enough sleep is already widely acknowledged, however many people of all ages fail to achieve this. Teenagers are recommended to get nine hours of sleep per night.

US researchers looked at 2,700 teenagers, 30% of whom went to bed after 11.30pm on school days and after 1.30am during their summer holidays.

The study found that by the time they finished school around the age of 17, those who had stayed up late had lower academic scores and were more likely to display emotional difficulties compared to their peers who had gone to bed earlier.

"Academic pressures, busy after-school schedules and the desire to finally have free time at the end of the day to connect with friends on the phone or online make this problem even more challenging," the researchers from UC Berkeley explained.

However, they noted that the results also indicate that teenagers who get enough sleep tend to do better emotionally and academically and this is a issue that can be tackled because sleep behaviour is ‘highly modifiable'.

Meanwhile, the study also found that going to bed late in the summer, but not during term-time, did not appear to affect academic achievement. However, it did seem to increase the risk of emotional difficulties in young adulthood.

"This very important study adds to the already clear evidence that youth who are night owls are at greater risk for adverse outcomes. Helping teens go to bed earlier may be an important pathway for reducing risk," the researchers added.

Details of these findings are published in the Journal of Adolescent Health.