Attention deficit hyperactivity disorder (ADHD) is vastly over-diagnosed with many cases simply immature children who are the youngest in their class. […] Around three to seven percent of British children are believed to have ADHD, about 400,000, with many being prescribed drugs to try and improve their concentration at school. […] Now a study of nearly 400,000 children between four and 17 years old in Taiwan has shown that the percentage of youngsters diagnosed with ADHD significantly changes depending on month of birth. Where just 2.8 percent of boys born in September have the condition, the figure jumps to 4.5...