For the study, researchers asked parents of children (ages 4-8) enrolled in a community-based study of child development about symptoms of attention and hyperactivity: whether or not children could wait their turn, interrupted others who were speaking, fiddled with things during meals or could not slow down, for example.
Out of the 62 children diagnosed with autism, 18 (29 percent) also showed signs of ADHD — and all were boys. The children with both conditions tended to have more problems with learning and socializing than children who had autism alone.
“In a child [with autism] who has great difficulties with attention, or hyperactivity or both, you really have to layer in another level of intervention strategies for them,” said study author Rebecca Landa, Ph.D., director of the Center for Autism and Related Disorders at the Kennedy Krieger Institute.
The researchers noted that treating symptoms of ADHD may benefit children if they aren’t making progress with autism treatment programs alone, which often require extended focus on specific skills.
An earlier study of slightly older children found that 31 percent of children had the two disorders together.
“We don’t know the cause for ADHD in most cases,” said Dr. Andrew Adesman, chief of developmental and behavioral pediatrics at Steven and Alexandra Cohen Children’s Medical Center, who was not involved in the study.
“We don’t know the cause of autism in most cases. It’s not surprising that something that’s going to affect the brain and cause one developmental outcome may also cause a second developmental outcome.”
“What’s good about this study is that they went to the trouble to look at who met diagnostic criteria and what was different about those children,” said Dr. Patty Manning-Courtney, director of the Kelly O’Leary Center for Autism Spectrum Disorders at Cincinnati Children’s Hospital Medical Center.
One limitation of the study was that researchers had to rely on questionnaires developed to spot ADHD in typical children. Currently, there aren’t any specific tests for ADHD designed for kids with autism, and their problems may look different than those seen in children without autism.
“It’s not that they have a deficit of attention. It’s that they can’t allocate their attention, or shift their attention to what it needs to be on,” said Courtney-Manning, who was not involved in the research. “I talk to parents of kids with autism about attention regulation more than attention deficit.”
In children who are more severely autistic, ADHD can be harder to spot.
“It’s hard to tell if their activity level is different because they’re delayed or they’re more severely autistic or if it’s ADHD,” Courtney-Manning said.
However, if parents and teachers are noticing that attention or activity problems are interfering with a child’s ability to make progress, it’s time to seek help, she noted.
First-line treatments would involve behavioral interventions that aim to teach kids to better control their focus. If the behaviors don’t improve, Landa said doctors will then move on to medication.
“If your child is having those kinds of problems, it’s worth mentioning to the child’s doctors and also touching base with the child’s teachers,” Landa said.