Bifactor models vs factor mixture models in the factorial structure of ADHD

Abstract

In the last decade, the bifactor model of Attention Deficit Hyperactivity Disorder (ADHD) has been widely investigated. This model consists of a general dimension of ADHD and two specific factors (inattention and hyperactivity / impulsivity). On the other hand, mixed factor models (FMM) have also begun to be implemented in the study of the structure of ADHD due to the possibility of combining categorical and continuous variables that facilitate the study of the latent reality of the disorder. The aim of the present work was to describe and analyse the research published in the last ten years (from 2008 to 2018) that were based on bifactor models and mixed factor models (FMM) for the analysis of the structure of ADHD. Given that, to date, there is no consistent evidence on an optimal model of the disorder in children and adolescents. For this, an exhaustive review based on a bibliographic search was presented, where the publications of scientific journals referring to the objective of the work were analysed. The studies conclude that the bifactor is superior to the traditional model of two correlated factors, according to the adjustment obtained by factor analysis, while the mixed factorial model of ADHD of two factors and two classes has shown a better adjustment than most of the bifactor models.