Interpreting intelligence test results for children with disabilities: is global intelligence relevant?

School psychological and neuropsychological evaluations typically include intellectual and other standardized assessment tools in the identification of children with disabilities. The clinical utility of intellectual assessment in the identification and treatment of these children has been repeatedly challenged, with alternatives such as a response to intervention or global intelligence score interpretation offered to replace the long-held tradition of idiographic interpretation of intellectual factors or subtests for the purpose of differential diagnosis and individualized intervention. Replicating previous work, this study examined the structure of intellectual functioning for children diagnosed with Learning Disability (LD; n=128), Attention-Deficit/Hyperactivity Disorder (ADHD; n=71), and traumatic brain injury (TBI; n=29) using regression commonality analysis. Across groups, results provide substantial evidence for a multifactorial representation of intellectual functioning for children with LD, ADHD, or TBI, with little shared variance among factor predictors of FSIQ in each analysis. As global intellectual functioning, represented by the shared variance among all predictors, was largely absent and instead composed of several discrete elements with the requisite specificity for individual interpretation, idiographic interpretation appears to be warranted for children with disabilities.