Background: Both parent-report and clinician-administered autism spectrum disorder (ASD) screening instruments are important to accurately inform ASD risk ascertainment. The aim of this study was to adapt a clinician-administered ASD screening instrument, the Autistic Behavioural Indicators Instrument (ABII), as a parent questionnaire equivalent…

We prospectively examined mean changes in Autism Diagnostic Interview-Revised (ADI-R) Total and Domains scores and stability of the ADI-R diagnostic classification in 28 children with autism initially assessed at age 2-4 years and reassessed 2 years later. Mean Total, Social Interaction, and Communication scores decreased significantly from Time 1…

Autism spectrum disorder and attention deficit hyperactivity disorder are neurodevelopmental disorders that cannot be codiagnosed under existing diagnostic guidelines ("Diagnostic and Statistical Manual of the American Psychiatric Association," 4th ed., text rev.). However, reports are emerging that attention deficit hyperactivity…