Youngest in class more likely to be diagnosed with ADHD

Children who are the youngest in their classroom are more likely to be diagnosed with Attention Deficit Hyperactivity Disorder (ADHD) than their older classmates, finds a new global study co-authored by UCL. The research, published in the  Journal of Child Psychology and Psychiatry , systematically reviewed studies that examine the relationship between a child's age relative to their classmates and their chances of being diagnosed with, or medicated for, ADHD. Seventeen studies covering more than 14 million children - five in the USA, two in Spain and one each in Canada, Finland, Germany, Netherlands, Iceland, Israel, Norway, Sweden, Taiwan and Australia - found it was more common for the youngest children in a classroom to be diagnosed with ADHD and medicated. Co-author Dr Joanna Moncrieff (UCL Division of Psychiatry) said: "The review finds that the diagnosis of ADHD is sometimes applied to behaviour that is disruptive in the classroom because the child is young for their year.  "Children who are developing within the normal range may end up labelled and medicated because of the pressures and inflexibility of our school system."  Lead author Dr Martin Whitely, Research Fellow at the John Curtin Institute of Public Policy based at Curtin University, Western Australia, said there are no biological markers or physical tests for ADHD and the diagnosis is based in large part on teacher reports of a child's behaviour.  "It appears that across the globe some teachers are mistaking the immaturity of the youngest children in their class for ADHD," said Dr Whitely.  "Although teachers don't diagnose it, they are often the first to suggest a child may have ADHD.