Is the Structure of ADHD stable across adulthood? Insights from the CAARS 2

It is well established that ADHD persists into adulthood with some changes in the clinical presentation, but structural stability of ADHD across different stages of adulthood has rarely been examined. This study used a multiple-group confirmatory factor analysis (CFA) approach to examine the measurement invariance of the latent 5-factor structure of the Conners Adult ADHD Rating Scales, 2nd Edition (CAARS 2) across stages of emerging (18-24 years), early (25-39 years), and middle adulthood (40-64 years). Data were drawn from the CAARS 2 general population and ADHD subsamples, including self-reported (n = 1684) and observer-generated (n = 1606) ratings. Results provide very strong evidence for configural, threshold, metric, and scalar invariance of the 5-factor correlated traits model across these three adult age groups for both Self-Report and Observer forms of the CAARS 2. This finding suggests a stable latent structure of ADHD across emerging, early, and middle adulthood. Evaluation and treatment of ADHD in adults may be enhanced by expanding beyond the two-factor DSM-5-TR model to reflect this 5-factor model (viz., Inattention/Executive Dysfunction, Hyperactivity, Impulsivity, Emotional Dysregulation, Negative Self-Concept), though further research on this important topic is needed. Additional clinical implications of the stability of the latent structure of ADHD across adulthood are discussed, along with methodological limitations and directions for future research.