MADISON, Wis. -- Up to 30 percent of children with attention deficit hyper activity disorder don't respond to prescription medication.

Researchers are testing herbal supplements to see if they make a difference for those with the disorder.

Adriana Arjona was diagnosed with attention deficit hyperactivity disorder when she was 6 years old.

Her mom chose herbal supplements to help her daughter, shying away from prescriptions to avoid side effects.

Researchers studied 54 children with ADHD ages 6 to 17.

Half of the children were given 900 milligrams of St. John's Wort and the other half were given a placebo.

Researchers found St. John's Wort does nothing to combat the effects of ADHD.