ASD symptoms in children with ADHD familial and genetic underpinnings

PhD ceremony: Ms. J.S. Nijmeijer, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: ASD symptoms in children with ADHD familial and genetic underpinnings

Promotor(s): prof. R.B. Minderaa, prof. J.K. Buitelaar

Faculty: Medical Sciences

Attention-Deficit/Hyperactivity Disorder (ADHD) and autism spectrum disorders (ASD) are strictly separated in the current classification systems. Recent studies have shown considerable overlap between both disorders, not only in symptoms, but also in genetic background. The aim of this thesis was to study the nature and origin of ASD symptoms in children with ADHD. A large, international database of children with ADHD and their families was used. Children with ADHD and their siblings presented more ASD symptoms than healthy controls. In addition to problems in social relationships, these children also experienced communication problems, stereotyped and rigid behaviours. ASD symptoms in children with ADHD and their siblings were similar. Children with ADHD and certain genes presented with more ASD symptoms, but only in children whose mothers had smoked during pregnancy, or who had a low birth weight. These findings point at the importance of gene-environment interactions in the development of ASD in children with ADHD.