Researchers say stimulants used to treat ADHD do not increase the risk of heart attacks, strokes, or sudden death.
Doctors studied the medical records of more than 1 million children and young adults aged 2 to 24 who had taken medications such as Ritalin or Adderall and found no sign of increased risk of heart problems.
The study is the first of three commissioned by the Food and Drug Administration after a number of reports in 2006 of heart attacks, strokes and sudden cardiac arrest in children taking those medications.
The study is published in the New England Journal of Medicine.
