The rate at which kids are diagnosed with attention deficit hyperactivity disorder (ADHD) is on the rise, according to USA Today. An analysis of health records from California also finds that boys are assigned the diagnosis three times more often than girls of the same age.
Twenty-four percent more children were diagnosed with ADHD in 2010, the last year for which data is available, than were in 2001. According to Darios Getahun, who works as a researcher for Kaiser Permanente Southern California Medical Group and was the lead author of the report, this represents a "significant" increase.
There remains a debate about whether the increase in the number of diagnoses represents the tendency of doctors to see the disorder where it doesn't exist or just a sign that more medical professionals and parents are becoming aware of the disorder.
The study looked at health records of more than 840,000 children, ages 5-11, who met a strict definition for ADHD, as diagnosed by a trained expert. It found that 2.5% of children were diagnosed with ADHD at the start of the study in 2001, vs. 3.1% in 2010.
The percentage diagnosed is lower than in many other studies because of the strict diagnostic criteria and because, unlike other research, the study relied only on health records, not parents' reports, Getahun says.
The results of the study published in JAMA Pediatrics were also broken down into demographic groups like gender, age, family income and race. The numbers showed that an ADHD diagnoses broke down rather unevenly along gender lines, with boys being diagnosed at three times the rate as girls. According to Craig Garfield of Northwestern University's Feinberg School of Medicine, that could be due to the fact that the way the disorder manifests in girls makes it much easier to overlook.
Garfield says that girls with ADHD more often present as inattentive rather than hyperactive – meaning disruptive – and therefore don't attract attention from teachers or parents.
Children of higher-income families are more likely to be diagnosed with ADHD, Getahun says, perhaps because their families are more concerned with their school performance and are more likely to seek a diagnosis.
Several ADHD experts question the validity of the study and whether the apparent increase in ADHD should be cause for concern.
Paul Hammerness, who specializes in ADHD at Harvard Medical school, says that he takes exception with words like "epidemic" and "dramatic" when describing the diagnosis rates for the disease. He said that from what he has observed, the rates at which disorders like ADHD are found in the population are actually fairly stable over time even across national borders.