International Meeting for Autism Research (London, May 15-17, 2008): Regression of Language and Non Language Skills in Pervasive Developmental Disorder

Regression of Language and Non Language Skills in Pervasive Developmental Disorder

Friday, May 16, 2008
Champagne Terrace/Bordeaux (Novotel London West)
9:30 AM
A. A. S. Meilleur , Psychology, McGill University, Montréal, QC, Canada
E. Fombonne , Montreal Children's Hospital
Background: As part of the Autism Spectrum Disorder (ASD), a subgroup of individuals display a different pattern of onset consisting of an apparently normal early development followed by a loss of verbal and/or non-verbal skills prior to age 2.
Objectives: This study aims at comparing the symptomatology of children who displayed a regression through investigation of 2 types of loss namely language and other skill regression.
Methods: This study examined the occurrence of regression in 135 children with ASD, mean age 6.3 years. The sample was composed of 80 (59.4%) children diagnosed with autism, 44 (32.6%) with PDD-NOS and 11 (8%) with Asperger syndrome. The Autism Diagnostic Interview Revised (ADI-R) was used to evaluate the type of loss and to characterize associated factors. 
Results: A total of 30 (22%) subjects regressed:  9 (30%) underwent language regression only, 17 (57%) loss a skill other than language, and 4 (13%) lost both language and another skill. Significantly higher levels of regression were found in autism (30%) compared to PDD-NOS (14%) and Asperger syndrome (0%). Children who regressed in language skills talked at a significantly earlier age (mean=12 months) than those who did not regress in this domain (mean=26 months). Parents and interviewers consistently reported developmental abnormalities prior to the loss. ADI-R domain mean scores indicated a more severe autistic symptomatology profile in children who regressed compared to those who did not, especially in the repetitive behaviour domain.
Conclusions: A loss of skill, present in 1 out of 5 children with ASD, is associated with a more severe symptomatology as measured by the ADI-R, particularly in the repetitive behaviours domain. Furthermore, although abnormalities are first noticed at the time of regression, the ADI-R reveals that other atypical behaviours are in fact present prior to the onset of regression.