The biggest study of its kind says Ritalin and other drugs used to treat attention deficit disorder are safe for adults' hearts.

The results echo findings in children published by the same authors last month.

The new review involved health records for more than 440,000 adults aged 25 to 65. It found that those on ADHD drugs had about the same number of heart attacks, strokes and sudden heart-related deaths as adults who didn't use those drugs.

The research will be published in the Journal of the American Medical Association's Dec. 28 print edition, but journal editors said they released it online Monday because of its public health importance.