According to the CDC, nearly 7-percent of American children have ADHD.
It's characterized by inattention, hyperactivity and impulsivity and is the most commonly diagnosed behavioral disorder in children.
Now new research suggests ADHD could be linked to obesity.
A study published in the journal "pediatrics," finds boys with ADHD had a greater risk of being obese, and having a high body mass index as they grew older.
For more than 30-years, researchers followed more than 200 white boys who met the criteria for an ADHD diagnosis.
Researchers started following them at around the age of 8 and checked back in with them around the ages of 18, 25 and 41.
Researchers found those with ADHD in childhood had significantly higher BMI's, and were about twice as likely to be obese by age 41.
The study was limited to white men, so it's not yet clear whether women or people from other racial groups with ADHD would be at the same risk of obesity.
Experts also aren't sure what's behind the apparent link, though they suspect the impulsivity associated with ADHD may make it more difficult for those patients to monitor their eating, which could lead to abnormal food habits and obesity.
Researchers say these long-term results should be considered when managing ADHD in childhood.