ADHD: An American Disorder?
In 2007 a comprehensive report lead by Guilherme Polanczyk found that the average prevalence of ADHD worldwide was 5.29%. But when the researchers looked at the data grouped by geographic area they found large discrepancies in the prevalence. The middle east was found to have the lowest rate of ADHD at about 2.5% while the highest was found, surprisingly, in South America at around 12%.
In a more recent study of school-aged children 9% were found to have been diagnosed with ADHD in the United States. Meanwhile, in France less than .5% of children are recognized as having ADHD. And in 2009 the rate of children age 5-9 diagnosed with ADHD in the US was four times higher than the rate of children diagnosed with ADHD in the UK.
What is the cause of this irregularity across countries? Well, the difference is primarily in the way ADHD is categorized and treated. The United States uses the definition of ADHD in the Diagnostic and Statistical Manual of Mental Disorders (DSM). While the World Health Organization has a slightly more restrictive definition which is listed in the International Statistical Classification of Diseases and Related Health Problems (ICD)
But what does this mean in practice? Let’s compare how the US and France look at ADHD as an example. In the United States, child psychiatrists classify ADHD as a biological disorder. Meaning that they view ADHD as being caused by a chemical imbalance in the brain. This leads primarily to the conclusion that treatment for children with ADHD should be pharmaceutical in nature. In France, on the other hand, ADHD is viewed as having psycho-social and situational causes. Therefore, French clinicians are much more likely to look for problems in the child’s social setting. This leads to lifestyle changes, which ultimately get to the root of the behavioral problem. As opposed to treating with pharmaceuticals which simply mask the symptoms of ADHD.
All in all, it is virtually impossible to compare the reported rates of ADHD in different countries and come to any meaningful conclusions because each country has its own system for diagnosing and treating ADHD.