So much for the old adage about "sleeping like a baby."
A study of 11-thousand kids from birth to age 7 shows that babies who snore a lot, or breathe through their mouths. are much more likely to become hyperactive at school-age.
Kids who didn't sleep well were also more likely to develop depression, anxiety, and aggressive behavior.
Doctors don't know yet if it's a cause-and-effect relationship, although they say it is the strongest evidence yet of a link.
But they are beginning to study if kids who have their tonsils out to relieve breathing problems also have better behavior.
When adults don't sleep well it can lead to many health problems, such as obesity and an increased risk for heart disease.
