Tanasa Davis says her daughter has always had trouble concentrating on school work.
"In preschool it was like she was driven by a motor, she was all over the place, the teachers were saying she was unfocused in class."
12-year-old Krystin has attention deficit hyperactivity disorder, or ADHD.
Kaiser Permanente in Southern California looked at 850,000 children and found the number diagnosed with the disorder rose 24% between 2001 and 2010.
The spike was most dramatic for African American girls, with a 90% increase.
Pediatrician Robert Moss says the findings don't mean more kids are getting the disorder. He believes doctors are better at recognizing the symptoms, especially in minorities.
"There's a large group of individuals that have issues with attention, with focus with organization that aren't necessarily hyperactive who are going missed for a number of years and we've begun to identify these individuals."
Kids with ADHD need extra help to get things done. Krystin now keeps a to-do list hanging in her room.
"It helps me stay organized," says Krystin.
A special timer allows also her to pace herself with school assignments. Once she sets it, there's no ticking sound to distract her, instead a red light comes on to show her when she needs to take a break.
Tanasa says the diagnosis changed their lives.
"When you know what your child is struggling through or what your child's challenges are, you're able to create a plan and support your child."
Kristin now takes medication too help her focus - and she uses her extra energy bouncing on her trampoline.