Social and language regression: characteristics of children with autism spectrum disorder in a community-based sample.

This study investigated the prevalence, and the developmental, behavior and emotional outcomes of 675 preschoolers with ASD with or without a history of regression, who participated in the Study to Explore Early Development (SEED). The SEED project is a cross-sectional case-control study that collected data between 2007 and 2011. Children's history of regression, adaptive skills, and behavior problems were assessed using the Autism Diagnostic Interview-Revised (ADI-R), the Vineland Adaptive Behavior Scales-Second Edition (Vineland-2), and the Child Behavior Checklist (CBCL), respectively; and children's developmental levels were assessed using the Mullen Scales of Learning (MSEL). Findings from this study indicated that 26% of children experienced social and language regression, and of those with regression, 76% had regained lost skills upon completion of the study. Compared to children without a history of regression, children with social regression demonstrated increased internalizing problems and decreased fine motor skills, and children with language regression demonstrated poorer language skills. Also, children with language and social regression displayed poorer adaptive communication skills than children without regression. Children who experienced regression in one area of development demonstrated better outcomes than those who experience regression in multiple areas. To conclude, children with regression are at risk for poorer outcomes during their preschool years.