Application of the Bifactor S – 1 Model to Multisource Ratings of ADHD/ODD Symptoms: an Appropriate Bifactor Model for Symptom Ratings

The symmetrical bifactor model is often applied to attention-deficit/hyperactivity disorder (ADHD)-hyperactive/impulsive (HI), ADHD-inattentive (IN), and oppositional defiant disorder (ODD) symptoms, but this model frequently yields anomalous or inadmissible results. An alternative model, the bifactor S – 1 model, is more appropriate for examining the hierarchical structure of ADHD/ODD symptoms. Both models were applied to ADHD-HI, ADHD-IN, and...