ABSTRACT
This chapter provides the analysis of the criteria used for diagnosing Attention Deficit Hyperactivity Disorder (ADHD) as defined by the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders. Sonuga-Barke, in discussing the scientific status of categorical models of childhood disorder, argued that assumptions underpinning the “medical model”—namely categorical, endogenous, and dysfunctional syndromes— constrain empirical study and development of theory. The use of latent class analysis in genetically informative designs is proposed by Sonuga-Barke (1998) as an approach to the investigation of nonlinear relations between symptoms and underlying aetiological factors. Structural modelling has been used to clarify the role of genetic and environmental factors in the aetiology of ADHD, and the influence of contrast effects on hyperactivity ratings. Inattention and Hyperactivity-Impulsivity scales are designed to describe the manifestation of the underlying disorders and the most basic descriptors of these disorders are the items of the scale.
