Dr. Sean McDonnell:

ADHD is extraordinarily problematic in terms of the development of peer support networks. At an early age, children with ADHD have difficulty developing such networks. They have a tendency to overwhelm other children in school during play or social activities and so can become quite isolated in school. That carries on and can lead to the development of and involvement in negative peer groups. That leads to exposure to some of the behaviours we talked about. They are more prone to getting involved in teenage difficulties, delinquent behaviours and early drug use. It is difficult with ADHD to know which comes first, the cart or the horse, but we know that very early on they have a tendency to experience social difficulties. If you can step in and inculcate social skills, it acts as a protective factor.