Children who have both autism and attention-deficit/hyperactivity disorder (ADHD) are also more likely to experience anxiety, depression, developmental delays, learning disabilities and other mental health conditions than are children with only autism or ADHD, according to a new population-based study.
Children with both conditions are four times as likely to have anxiety and three times as likely to have depression as autistic children without ADHD. They are also four times as likely to have a learning disability and seven times as likely to have developmental delay compared with children who have only ADHD, the researchers found.
“If we know that children who have co-occurring conditions are more likely to have depression or anxiety, then the treatment can be geared to help ameliorate the symptoms,” says lead researcher Myriam Casseus, a research scientist in the pediatrics department at Rutgers University.
Autistic boys with ADHD are more likely to receive behavioral treatment than autistic girls with ADHD. And older autistic children with ADHD are more likely to receive psychotropic medications than those without ADHD. Children with both conditions are more likely to have both public and private health insurance than children with only one of the conditions, the researchers found. Parents of children with both may need to get supplementary insurance to cover the added mental health needs, Casseus says.
The findings were published in Autism Research in January. “They find striking increases in mental health conditions in the group that are co-diagnosed with autism and ADHD,” says Sarah Karalunas, associate professor of psychological sciences at Purdue University in West Lafayette, Indiana, who did not take part in the work. “The new findings will help clinicians to be more aware of the conditions that might develop and make earlier interventions to prevent those outcomes.”
The results bolster the idea that children with co-occurring autism and ADHD need more care to treat the mental health conditions that can derive from the combined conditions, Casseus says.
Clinicians could not diagnose a child with both autism and ADHD until 2013, when the current version of the Diagnostic and Statistical Manual of Mental Disorders debuted and declared that the two conditions are not mutually exclusive. Studying the overlap between the two, and knowing that children with both conditions often have additional mental health needs, might help researchers design treatment plans specific to them, Casseus says.
About the survey
The results draw on data from more than 6 million children aged 3 to 17, collected from 2016 to 2018 by the U.S. National Survey of Children’s Health, an annual questionnaire that asks parents about their children’s medical diagnoses and treatments. Among those children, 949,367 have autism, 4,570,320 have ADHD, and 740,816 have both conditions.
The study did not independently verify the children’s treatments or diagnoses via clinical evaluations and other data—a weakness of the study, Fodstad says. “There can be some bias and subjectivity there.”
Future work should consider why specific traits, such as repetitive behaviors, occur with both autism and ADHD, Casseus says.
Maaisha Osman is an editorial intern writing articles about the latest autism research for Spectrum.