Determining the efficacy of the BASC-2 PRS in the differential diagnosis of autism and attention-deficit/hyperactivity disorder

Autism and ADHD are two distinct disorders that share many overlapping symptoms, including attention problems, hyperactivity, behavior problems, and social skills deficits as well as co-occurring problems, such as mood disorders, emotional lability, anger, and conduct problems. The Behavioral Assessment System for Children, Second Edition (BASC-2; Reynolds & Kamphaus, 2004) is a frequently used behavioral rating scale designed to aid in the assessment of a variety of social and emotional problems. However, there is limited research on the use of the BASC-2 comparing the behavioral profiles of children with autism and ADHD, and the available research is flawed by methodological issues or has only examined autism or ADHD relative to typical development as opposed to comparing the two disorders. Given the potential of the BASC-2 to assist in the differential diagnosis of autism and ADHD, the current study aimed to compare maternal behavioral ratings of children diagnosed with ADHD and autism to each other and to children with neurotypical development using the BASC-2 PRS. Group profiles were compared to determine which composites and scales were significantly different between diagnostic groups and which of the composites and scales were most predictive of diagnosis. Overall, children with a psychoeducational diagnosis were rated as having more maladaptive behaviors compared to children without a diagnosis. However, the level of severity differed between the autism group and the ADHD group. In general, children with autism received ratings indicating more maladaptive behavior than children with ADHD or neurotypical children. These finding support previous research indicating that children with autism tend to have more exaggerated behavioral problems than children with ADHD. Scales that showed significant group differences for children with autism and ADHD were then used to determine which of those scales were most predictive of diagnosis. The Withdrawal and Atypicality scales were determined to be the most predictive of diagnosis in the study sample. These scales were then used to create a weighted formula that can be used to predict the likelihood of a diagnosis of autism versus ADHD. Clinicians and school-based personnel can easily apply the findings of this study when conducting assessments with children suspected of having these disorders.