 Many children with ADHD have, beside the main symptoms hyperactivity, impulsivity and a lack of ability to maintain attention, difficulties with social interaction. This is a burden in the childrens relationship towards parents, peers and teachers and thereby influencing their performances in school. Many children with ADHD find great help in receiving medical treatment, which has a good effect on the childrens problems with hyperactivity, impulsivity and lacking attention. However, social interaction problems will probably not be set right due to medication alone. Several studies have shown that social skills training can help children with ADHD in their social interactions. It is also an interesting issue to further investigate treatment effect in relation to the ADHD-childrens attachment competences, as one must assume that differences in attachment competences may influence the childrens relationship and social interaction problems. 