Helland, W. A. 1, 2 , Posserud, M. 3 , Helland, T. 4 , Heimann, M. 5 & Lundervold, A. 6
1 Department of psychiatry, Helse Fonna HF, Norway
2 Statped, Norwegian Support System for Special Education
3 Department of Child and Adolescent Mental Health, Haukeland University Hospital, Bergen, Norway
4 Department of biological and Medical Psychology, University of Bergen, Norway
5 Department of Behavioural Science, Linköping, Sweden
6 Centre for Child and Adolescent Mental Health, Uni Research, Bergen, Norway
Attention deficit hyperactivity disorder (AD/HD) and RD are the two most prevalent neurodevelopmental disorders of childhood, and high rates of comorbidity have been reported for both disorders. This large scale population-based study aimed to explore whether children with symptoms of AD/HD, children with symptoms of RD, children with symptoms of both AD/HD and RD and a control group could be differentiated from each other regarding different aspects of language; phonology, expressive language, receptive language and pragmatics. Method: Out of a sample of 5672 children aged 7-9 years four groups were derived based on the results of a screening questionnaire distributed to teachers and parents of the children; children with RD (N=332); children with ADHD (N=169); children with AD/HD + RD (N=121) and a control group (N=5050). Results: All groups differed significantly on phonology and expressive language; the ADHD+RD group being most severely impaired, followed by the RD group, the ADHD group and the controls. On receptive language significant differences were also revealed between all groups, with the ADHD+RD group being most impaired, here followed by the ADHD group, the RD group and the control group. Regarding pragmatics a somewhat different picture was found; although the ADHD+RD group was most severely impaired and the control group was not, the difference between the ADHD group and the RD group did not reach significance on this item (p=.02). Conclusions: In sum these findings support findings from clinical samples pointing to a considerable rate of language impairments both in children with symptoms of AD/HD and in children with symptoms of RD. Although children with ADHD and children with RD share many symptoms of language impairments, they can be differentiated from each other regarding some aspects of language.