(RxWiki News) Being impulsive and easily distracted can be typical childhood behaviors. If these behaviors happen constantly and interfere with a child's ability to function, however, it may be ADHD.
Rates of attention deficit hyperactivity disorder (ADHD) appear to be increasing among children in the US. However, past studies have had weaknesses that make it difficult to know the real rates of the condition.
A recent study looked at patterns of diagnosis over 10 years for ADHD in a large group of children. The children came from diverse backgrounds, and the diagnoses were all made by doctors.
The researchers found that ADHD diagnosis rates increased by 24 percent over ten years. Boys were more likely to be diagnosed with ADHD, but girls may be catching up.
"Ask a doctor for help managing your child's ADHD."
The study was led by Darios Getahun, MD, PhD, of the Department of Research and Evaluation at West Los Angeles Medical Center in the Kaiser Permanente Southern California Medical Group.
The researchers looked at the medical records for all children aged 5 to 11 who received care in the Kaiser Permanente Southern California system between January 1, 2001 and December 31, 2010.
The researchers specifically looked for diagnoses of ADHD in these 842,830 children. To be a confirmed ADHD diagnosis, the child had to meet the criteria in the Diagnostic and Statistical Manual-IV (DSM-IV).
The DSM-IV criteria requires children to exhibit symptoms for at least six months, to have problems from symptoms in at least two settings (i.e., home and school), and to be "significantly affected by one or more clinical impairments."
The rate of ADHD diagnosis in 2001 was 2.5 percent, which rose to 3.1 percent in 2010. This increase is a 24 percent increase.
The researchers also looked at the rate of diagnosis by children's race/ethnicity, age, sex and household income.
They found that children in higher income households were more likely to be diagnosed with ADHD.
The rate of ADHD diagnoses increased among white children from 4.7 percent in 2001 to 5.6 percent in 2010.
The rate of ADHD diagnoses increased among black children from 2.6 percent in 2001 to 4.1 percent in 2010. This increase primarily occurred among black girls diagnosed with ADHD.
The rate of ADHD diagnoses increased among Hispanic children from 1.7 percent in 2001 to 2.5 percent in 2010. The rates remained steady for Asian/Pacific Islander children and other racial groups.
The researchers noted that Asian children were less likely to seek mental healthcare and more likely to stop using therapy even though their access was the same as other groups.
"This finding suggests that cultural factors may influence the treatment-seeking behavior of some groups," the researchers wrote.
The researchers said a variety of factors may be contributing to the increases they saw with ADHD diagnosis.
"Although the reasons for increasing ADHD rates are not well understood, contributing factors may include heightened ADHD awareness among parents and physicians, increased use of screening and other preventive services, and variability in surveillance methods among institutions," they wrote.
They acknowledged that diagnosing ADHD is challenging because the symptoms can often look like normal childhood behaviors, such as being "easily distracted, impulsive, and unable to concentrate on simple tasks for even short periods and [becoming] disruptive in the classroom."
However, they noted that kids with ADHD "show persistent patterns of extreme behavior beyond their control."
The researchers said that the use of the DSM-IV criteria and the large population of demographically diverse children included in this study make their estimates more likely to be representative and accurate than many other recent studies on ADHD diagnoses.
However, that is not necessarily the case, said Glen Elliott MD, PhD, a dailyRx expert and a clinical professor at the Stanford University Department of Psychiatry and Behavioral Sciences.
“Although this is an important study, it would be premature to conclude that the true prevalence of ADHD is changing," said Dr. Elliott, also chief psychiatrist and medical director at Children's Health Council, a non-profit mental health facility affiliated with Stanford.
He noted that the group of children used in the study were referred to the study, which means the researchers may not have captured a representative population of children in the first place.
"Since there is no blood test for ADHD, the diagnosis depends on reports of a number of behaviors, and those reports can be influenced by many variables, including the belief in effective treatment for ADHD," Dr. Elliott said. "Studies in classrooms have shown that pediatric clinics are not representative of ADHD in the general population, and changes reported here may have more to do with referral patterns than with ADHD itself.”
The study was published January 21 in the journal JAMA Pediatrics. The research was funded by Kaiser Permanente Direct Community Benefit funds. The researchers reported no conflicts of interest.