Professor Rapson Gomez is a clinical psychologist with specific expertise in statistical modelling, personality measurement, and a variety of clinical conditions (especially Attention Deficit Hyperactivity Disorder). He received degrees from the University of Melbourne, the University of Stirling (UK), and the University of Newcastle-upon-Tyne (UK). He has held positions at the University of Ballarat and the University of Tasmania. His current affiliation is with Federation University.
Title: Resolving Controversies in the Structure, Organization and Content of ADHD Symptoms Using Latent Variable Procedures
Attention Deficit/Hyperactivity Disorder (ADHD) is conceptualized differently in the Diagnostic and Statistical Manual (DSM-5 and DSM-5-TR, 2022), and the International Classification of Diseases-10 (ICD-10, 1990 and ICD-11, 2022). All these frameworks consider inattention (IA), hyperactivity (HY) and impulsivity (IM) as the core symptoms for ADHD, This keynote address will present a series of six studies involving children, adolescents and adults, conducted in our laboratory, that applied independent cluster confirmatory factor analysis (ICM-CFA), exploratory structure equation model with target rotation (ESEM), and symmetrical and asymmetrical (S -1) bifactor CFA and ESEM approaches to evaluate a range of potential ADHD models yielded by different combinations of these taxonomic frameworks. Within each study, the different models were compared using the stepwise algorithm for model selection (SAMS) procedure, a novel approach we developed for selecting the optimum model from a group of competing models. It involves in sequence model fit, and factor clarity, reliability, and validity criteria. Regardless of the sample examined, for all studies that did not test ESEM models, the findings showed most support for the asymmetrical (S-1) bifactor CFA model, based on ICD-10 configuration, with a general factor based on IM symptoms as the reference indicators, and IA and HY symptoms as specific factors. However, this model was not as well supported when compared to the ESEM model, with ICD-10 symptoms as the group factors. For both these S-1 and ESEM models, the HY specific/group factor lacked clarity and reliability. Thus, we propose that structurally, ADHD is best viewed as a disorder primarily reflecting ICD-10 symptoms for IA and IM (but no HY), and that it could be referred to as “attention deficit/impulsivity disorder” or ADID.