Harmonizing DSM-IV and DSM-5 Versions of ADHD "A Criteria": An Item Response Theory Analysis

The transition from Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev.; DSM-IV-TR) to Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) attention deficit/hyperactivity disorder (ADHD) checklists included item wording changes that require psychometric validation. A large sample of 854 adolescents across four randomized trials of psychosocial ADHD treatments was used to evaluate the comparability of the DSM-IV-TR and DSM-5 versions of the ADHD symptom checklist. Item response theory (IRT) was used to evaluate item characteristics and determine differences across versions and studies. Item characteristics varied across items. No consistent differences in item characteristics were found across versions. Some differences emerged between studies. IRT models were used to create continuous, harmonized scores that take item, study, and version differences into account and are therefore comparable. DSM-IV-TR ADHD checklists will generalize to the DSM-5 era. Researchers should consider using modern measurement methods (such as IRT) to better understand items and create continuous variables that better reflect the variability in their samples.