NORTH TEXAS (CBS 11 NEWS) – A new safety study is helping ease the minds of millions of parents who have children with Attention Deficit-Hyperactivity Disorder, or ADHD.

Researchers have now ruled out the risk of serious heart problems once associated with medications used to treat the syndrome, which effects more than five million children in the United States.

The study, published Tuesday in the New England Journal of Medicine, shows the risk of heart attack, stroke or sudden death is no greater for children who are on ADHD medicine compared to those who are not.

“The study does not surprise me,” said Texas Health psychiatrist Dr. Syed Quadri. “If used as prescribed they are very safe, but like every other medication there is a risk versus benefit.”

Ritalin is one of the most common drugs prescribed to treat ADHD, a condition characterized by hyperactivity, impulsivity and attention problems.

Rowan Hines, 11, of Fort Worth, was diagnosed with ADHD about two years ago, and takes Ritalin during the week to control his symptoms and help him focus on schoolwork.

“It wasn’t necessarily something we wanted to do,” Rowan’s mother, Stephanie Hines, explained, “but after lots of research we found it was probably best to put him on a low dosage.”

Hines says she was concerned at first because of the heart risks once associated with the stimulant drugs, but the new study gives her reassurance.

The family has also found another way to curb Rowan’s disorder. The sixth grader started cycling with his father, Casey, last Spring.

Since starting the physical activity, his parents say they’ve seen a significant improvement in his behavior, so much so that he no longer needs his ADHD medication on weekends.

“He’s a big advocator of riding,” Hine’s said of her son. “It gives [him] those natural endorphins that your body does when you’re doing athletic activity.”

Hines said they plan to continue using Ritalin as long as Rowan needs it, but they’ll also explore other natural remedies, like cycling, to supplement his medication.