Sunday, February 9, 2014

ADHD: The Big Picture

The January 2014 issue of JAACAP had an article detailing the rise in ADHD rates over the past decade: "Trends in the Parent-Report of Health Care Provider-Diagnosed and Medicated Attention-Deficit/Hyperactivity Disorder: United States, 2003–2011." The study is part of the CDC's National Survey of Children’s Health, and the authors reported the following results (the 2011 numbers had previously been widely reported elsewhere):
In 2011, 11% of children/adolescents aged 4 to 17 years had ever received an ADHD diagnosis (6.4 million children). Among those with a history of ADHD diagnosis, 83% were reported as currently having ADHD (8.8%); 69% of children with current ADHD were taking medication for ADHD (6.1%, 3.5 million children). A parent-reported history of ADHD increased by 42% from 2003 to 2011. Prevalence of a history of ADHD, current ADHD, medicated ADHD, and moderate/severe ADHD increased significantly from 2007 estimates. Prevalence of medicated ADHD increased by 28% from 2007 to 2011.
To me, the most interesting figure in the paper was a map of the U.S. showing how rates of parent-reported ADHD and medication treatment varied by state. Here's the map of what percentage of children in each state had a parent-reported diagnosis of ADHD:

Unfortunately, the authors do not even mention this large geographic variation in the paper's discussion section, and neither does the accompany editorial, titled "Beyond Rising Rates: Personalized Medicine and Public Health Approaches to the Diagnosis and Treatment of Attention-Deficit/Hyperactivity Disorder." Drs. Walkup, Stossel, and Rendleman from Weill Cornell Medical Center made the following argument:
In summary, the public health goal to improve recognition and treatment of ADHD is paying off in the United States. The rate of parent-reported ADHD diagnosis looks similar to community- based prevalence estimates. The rate of medication use approaches 70% of currently diagnosed cases, suggesting a substantial proportion of those with ADHD diagnoses are receiving treatment. It is important to not over-react simply to the notion of increasing rates of diagnosis and treatment without considering the whole picture. It is absolutely critical to benchmark current diagnosis and treatment rates against prevalence estimates to best serve the public health.
This editorial is one of the more ridiculous things I have ever read in an academic journal. First, as is widely known, ADHD misdiagnosis is rampant, which I have previously blogged about. Second, if we're to talk about a public health approach, to me that would go beyond identifying children with ADHD and medicating them; it would entail trying to figure out why rates of ADHD are so much higher in certain places than others, and then trying to address the root causes that contribute to those regionally higher rates.

Around the same time I read this JAACAP article, I read about the release of a landmark report on social mobility in the United States. The report, by the National Bureau of Economic Research, examined the incomes of over 40 million parents and their children from 1996 to 2012, looking at the factors that influenced how well the offspring did economically. Again, I was fascinated by a map showing how rates of upward mobility differed across the U.S.:

While the maps are obviously not identical, they are similar in that the Deep South and Rust Belt stand out on both, with higher rates of ADHD and lower levels of income mobility. I wish that the CDC study had more detailed local prevalence data than the state-level numbers, so the two maps could be more directly compared. The economists examined factors correlated with upward mobility and found:
High mobility areas have (1) less residential segregation, (2) less income inequality, (3) better primary schools, (4) greater social capital, and (5) greater family stability.
I would not be surprised if many of the above factors – especially family stability – also influence regional variation in ADHD rates. But regardless of the reasons behind the variation in ADHD diagnosis, it's clear to me that ADHD is not just a "brain condition," and I wish that more psychiatrists would be interested in investigating the bigger picture.