Many people ask if ADHD is over-diagnosed in children. I get comments from parents like, “So many children in my kid’s school are taking medication for ADHD, what’s going on.” The scientific answer is tricky.
We first have to clarify what over-diagnosis is. In scientific terms, it is a false positive, or diagnosing a child with ADHD who in fact doesn’t have the condition. Another error that can occur is a false negative or failing to diagnosis ADHD in a child who actually does suffer from the condition. Since we do not have a 100% accurate test for the ADHD diagnosis (by the way few conditions in medicine have such tests), we rely on expert diagnosis using varied methods. Yes, this method is imperfect. We are constantly doing research to improve diagnostic accuracy, but don’t be misled to think that ADHD is not a real condition. The science behind the validity of the diagnosis is excellent.
It is also important to understand that ADHD is a common childhood condition and studies across different countries find a prevalence rate of somewhere between 3 to 7 percent of children suffer from this condition. A world-wide systematic study found the rate at 5%. Boys have a higher rate of this condition than girls.
What we have also discovered that characteristics such as age, race, gender, and where you live affect prevalence rate. If your child is older, Caucasian, male, and you live in an urban setting, he is more likely to get a diagnosis and be in that 3 to 7 percent group.
We have also discovered that over-diagnosis, or false positive errors, are more likely to occur when the diagnosis is based on a single office visit with a doctor who does not use a multi-model assessment procedure (this also leads to a higher false negative rate by the way). It is important to realize that the actual problem is that there is more mis-diagnosis overall.
One study found that only 59% of children diagnosed in single office visit mainly by pediatricians were diagnosed correctly (this includes false positive and false negatives). This was established by having a second doctor who rigorously followed practice guidelines of multimodal assessment to confirm the initial diagnosis. In an even more carefully done study, the over-diagnosis rate or false positive was 17% in cases reviewed, but not all these children were actually treated with medication.
Diagnostic errors can therefor lead to two problems. The first is inappropriate treatment such as giving a child medication when he/she does not need it, but also a failure to treat, which is not giving medication to a child who needs it. Interestingly, while errors are high in some settings as discussed above, treatment with medication is not over the expected prevalence rates. The medication rate for ADHD was 6% as reported in 2011 for school aged children in the US. This is in line with prevalence rates, but of concern is that this number is far higher in some communities and has crept up over the years overall. Interestingly, treatment rates in Europe are lower even though their prevalence rates are similar to ours (an example of how “culture” can affect treatment decision-making). We also know in the US that Caucasian boys are treated more than females and other races with medication. Studies show that Caucasian boys are twice more likely to get medication treatment than African-American boys. Thus, there is a percentage of children in these other groups who are not being treated (who may benefit from medication treatment). Many factors including access to care affect treatment rates.
The “big” result here is that the initial diagnosis of ADHD has to be done carefully. The doctor should follow research-based practice guidelines that use multi-modal assessment procedures. It is also important that all children with ADHD get screened for learning disabilities since a child with ADHD is at far greater risk for these conditions as well.