Severe problem behaviors such as self-injury and aggression are frequently observed in young children under age 5 with intellectual and developmental disabilities (IDD). Although early identification of problem behavior is critical to effective intervention, there are few standardized measures available that identify severe problem behavior in…

The Autism Spectrum Quotient (AQ) has been widely used for measuring autistic characteristics in parents of children with autism spectrum disorders (ASD). Nonetheless, its psychometric validity is yet to be justified. This study tested the factor structure of the AQ by means of principal component analysis and confirmatory factor analysis using,…

Attention deficit hyperactivity disorder (ADHD) is prevalent in the adult population. The associated co-morbidities and impairments can be relieved with treatment. Therefore, several rating scales have been developed to identify adults with ADHD who may benefit from treatment. No systematic review has yet sought to evaluate these scales in more…