Author and ADHD expert Chris Dendy spoke at the ADDA-SR Conference hosted by Briarwood School February 25th, about research that shows the slower development of the brain in children and young adults with ADHD. On the whole, there is a lag of 2.5 to 3 years, or 30%, in the executive functioning region of the brain of a student with ADHD and a student without. This explains a lot about why a ten-year- old might act like a 7-year-old or a sixteen-year-old may act like a thirteen-year-old. Impulsivity, lack of emotional inhibition, and poor organization are among EF Skills that make the ADHD kiddo look less mature than his peers. Research was done by Barkley and Shaw.