From 1998 to 2016, the rate of attention deficit hyperactivity disorder in US children has gone up from about 6% to over 10%, according to a study published Friday (Aug. 31) in JAMA Pediatrics.
Researchers from the University of Iowa and the Shenzhen Children’s Hospital in China tracked survey results from the National Health Interview Survey, which is administered by the US Centers for Disease Control. The survey is given annually and includes about 35,000 households across the US. Among other questions, it looked for diagnoses of ADHD in children aged 4 to 17 over two year periods.
ADHD is characterized by symptoms like inability to focus, trouble completing tasks, difficulty paying attention, and ignoring instructions, as well as fidgety, talkative, or impulsive behavior according to the American Psychiatric Association (APA). As a result, children with ADHD may underperform in school. Previous estimates suggested that about 8.2% of children living in the US had ADHD.
Although the data appear to suggest ADHD is becoming more prevalent, that likely isn’t the case. More likely, doctors are diagnosing children with the condition more often than before. As with most other mental-health conditions, there’s no definitive test to say whether a child has ADHD or not; it’s diagnosed instead by observing and analyzing symptoms.
The survey was first given in 1997-1998, and in 2013, the APA updated the symptoms for ADHD to also include inattentiveness, which girls with the condition exhibit more often, CNN reports. Since then, girls who were previously undiagnosed have been more likely to be included in these data. It’s also likely that more children have had access to healthcare since the passing of the Affordable Care Act in 2010. Both factors likely played a role in the increase in the number of cases over the period of two decades, particularly among students who were not white, who had the largest increase in diagnoses.