If your preschooler can't sleep -- turn off the violence and nighttime TV.
That's the message in a new study that found sleep problems are more common in 3- to 5-year-olds who watch television after 7 p.m.
Watching shows with violence -- including kids' cartoons -- was also tied to sleeping trouble. Problems included difficulty falling asleep, nightmares and daytime sleepiness.
Viewing nonviolent shows during the day didn't seem to have any connection with sleep problems in the more than 600 youngsters studied.
The study builds on previous research linking media use with kids' sleep problems, and also bolsters arguments for limiting screen time for very young children.
The study was released online Monday in Pediatrics.