Certain medications used to treat ADHD with psychostimulants might increase heart problems, a new study has found.

Psychostimulants are often used to treat children and teenagers suffering from attention-deficit/hyperactivity disorder (ADHD).

ADHD is characterized with the inability in paying attention, controlling behavior and being overtly active. Around one in every ten children in the U.S. has ADHD. The condition can't be cured, but can be controlled.

Previous research has shown that children taking drugs such as Adderall and Ritalin do not have an increased risk of serious heart conditions during treatment.

The study conducted by researchers at the Aarhus University and colleagues, shows that doctors treating ADHD need to be aware of certain risks that the drugs carry.

The study was based on data from 700,000 children in Denmark, of which 8,300 had ADHD. The team compared stimulant-use and cardiovascular events in children with ADHD and the entire study group. They found a small by statistically significant risk associated with stimulant use for ADHD.

"This study confirms the small but real risk we have understood for some time through prior reports and clinical experience," said Harold S. Koplewicz, M.D., Editor-in-Chief of Journal of Child and Adolescent Psychopharmacology and President, Child Mind Institute, New York, NY, according to a news release.

"But Dalsgaard et al.'s excellent design and the robust sample size make it abundantly clear that treating clinicians cannot ignore existing guidelines concerning the assessment of cardiac risk prior to treatment and monitoring key vital signs during the course," Koplewicz added.

The study is published in the Journal of Child and Adolescent Psychopharmacology.