Scientists are reportedly telling parents to pay closer attention to teens’ sleep schedules.

Researchers have reportedly found that poor sleep in teenage years could be an early warning sign of alcohol problems, illicit drug use and “regretful” sexual behavior, according to BBC News.

“Most of the time we don’t think sleep is important. But our results show sleep is a good marker of some serious later problems,” Professor Maria Wong who led the study told the news outlet.

For the study, scientists reportedly analyzed data from more than 6,500 adolescents in the United States. They reportedly tracked sleep patterns, alcohol and drug use based on a nationwide survey that was conducted between 1994 and 2002.

Teenagers who reported trouble going to sleep at least once a week were reportedly more likely to binge drink, engage in sexual behavior that they later regretted when drunk or take illicit drugs in the following years. Those who found it difficult to fall asleep were reportedly 33% more likely to experience these issues compared to teenagers who had more consistent sleep, according to the media outlet Newsledge.

The teenagers that got the sleep they needed reportedly got some protection from engaging in behavior such as binge drinking. It might be time for parents to help their kids sleep and encourage more of it.

“A lot of parents don’t monitor their adolescents’ sleep schedules and let them make their own decisions about when to go to bed,” stated Wong.

She added, “But parents need to start talking to their teenagers, not just about grades and extracurricular activities but about sleep too. And they must get help if needed.”