November 12 (HealthDay News) -- The U.S. Food and Drug Administration has approved a 30-minute onset of action for Focalin XR (dexmethylphenidate HCI extended release) to treat attention-deficit hyperactivity disorder (ADHD), maker Novartis Pharmaceuticals said Wednesday.

The early onset could especially benefit children ages 6 to 12 during the morning as they get ready for school, the company said in a news release. The drug helps curtail symptoms for up to 12 hours.

ADHD affects about 3 percent to 6 percent of children in the United States, with symptoms including inattention, hyperactivity, and impulsive behavior, Novartis said.

The new labeling is based on clinical data, including a study of 86 children ages 6 to 12. The drug provided significant symptom improvement 30 minutes after administration, compared to a non-medicinal placebo, the company said.

The most common adverse reactions included abdominal pain, headache, increased appetite, and viral gastroenteritis.