Two million children in the U.S. have been diagnosed with attention deficit hyperactivity disorder (ADHD) and many of them are being treated with psychoactive medications.  A new study shows that for some kids, there may be an alternative treatment.

About a year ago, Nathaniel Junior stopped sleeping through the night.

“When he did fall asleep, he’d sleep well for about an hour or two,” says Nathaniel Miles, the boy’s father.

But then Nathaniel Junior would be up in the middle of the night, and in the morning, his lack of sleep would affect him.

“He’d be just kind of cranky,” says Miles.

Cranky, restless, hyperactive and impulsive are symptoms of ADHD, but experts say they are also symptoms caused by lack of sleep.

“They’re usually hyperactive and can’t concentrate, and they’re fidgety in class and don’t do well in school because of those things.  People might even look at them and say they have attention deficit disorder, but they’re actually sleep deprived,” says Dr. Gary Montgomery, M.D., Children’s Healthcare of Atlanta.

In fact, researchers at the University of Michigan tracked 22 children with ADHD who also had trouble sleeping. One year after the children in the study had their tonsils removed, half of them no longer had any symptoms of ADHD.

“We have lots of studies that show that after an Adenotonsillectomy, the children actually feel better, they sleep better at night and they do better in school,” says Montgomery.

Nathaniel, Jr. had the same results. After a tonsillectomy, he now sleeps through the night and is no longer cranky throughout the day.

“Well, now when he wakes up in the morning he’ll run and play all day long, which means he got enough rest that night,” says his father.

Experts say that parents of a child with ADHD should let their pediatrician know if their child is having sleep problems.