How many children have ADHD?

The frequency of occurence of ADHD can vary from country to country. We may note that funnily, the instances of ADHD in developed countries is higher than in under-developed countries. This is majorly attributed to the lack of established mechanisms to diagnose and treat the condition in most developing countries. Or in other words, the frequency could be much more outside of the developed world, but the infrastructure needed for diagnosis and treatment or for the documentation and assimilation of pertinent information is more often than not absent. So there may not be one reliably accurate number that gives the frequency of ADHD in children and young adults. But there are studies that show that it could be as varied as 3.5% in some countries (most likely developed ones) to as low as 1 in 250, or, about 0.4% in other countries (most likely in under-developed countries).

What also complicates the problem is, the definition of ADHD and minor hyperactivity is subject to debate. Some thought leaders also debate the validity of ADHD as a significant mental condition. Hope this helps.

ADD/ADHD is the most commonly diagnosed disorder of childhood, estimated to affect 3 to 5 percent of school-age children, and occurring three times more often in boys than in girls. It is estimated that on average about one child in every classroom in the United States needs help for this disorder.

No one knows for sure whether the number of people with ADD/ADHD has risen, but it is very clear that the number of children identified with the disorder who get treatment has risen over the past decade. This could be due to greater media interest, heightened consumer awareness, and the availability of effective treatments. Other countries are observing a similar pattern. Whether the frequency of the disorder itself has risen remains unknown, and needs more research.