AD/HD is thought to affect 3-7 percent of school-aged children.
• Evidence suggests that boys are three times more likely to have AD/HD than girls, although the higher rate may be due to the greater prevalence of behavioral and conduct problems in boys, leading to a higher referral rate.
• AD/HD is a strongly inheritable condition. If a family has one child with AD/HD there is a 30-40 percent chance that a brother or sister will also have the condition. More than half of all parents with AD/HD themselves will have a child with AD/HD.
• Experts estimate that up to 60 percent of children with the disorder carry their symptoms into adulthood.
