Developmental profiles of young children with autism spectrum disorder and global developmental delay: A study with the Griffiths III scales

The purpose of this study was to identify developmental profiles associated with autism spectrum disorder (ASD) and global developmental delay (DD) in pre-school aged Italian children. Developmental profiles were evaluated by means of a standardized tool widely used for the assessment of psychomotor development in early childhood, the Griffiths III scales, recently adapted and standardized for the Italian population. Specifically, we compared the Griffiths III profiles of children with ASD and DD (ASD + DD) with those of children with DD alone. Moreover, we inspected the psychometric function of single items by comparing children with ASD + DD and children with DD with typically developing (TD) children from the Griffiths III normative sample. In this way, we aimed to isolate the effects of each diagnostic class on psychomotor abilities and on the psychometric function of single items. The ASD + DD and DD groups were found to share the presence of lower age equivalent scores relative to their chronological age in all the developmental domains considered: Foundations of Learning, Language and Communication, Eye and Hand Coordination, Personal–Social-Emotional and Gross Motor Skills. However, the DD group displayed a homogeneous profile with similar levels of delay in all developmental domains, while children with ASD + DD exhibited relative weaknesses in the Language and Communication and Personal–Social-Emotional scales. The analysis of the psychometric function drawn for each item has confirmed different profiles in social-communicative and non-verbal items between the two diagnostic groups and in relation to TD normative sample. The Griffiths III is a valid psychometric tool for identifying atypical developmental profiles and its use may be recommended during the diagnostic process of ASD and DD, to detect specific strengths and weaknesses and guide person-centered treatment.