The Hierarchical Taxonomy of Psychology (HiTOP): origin, development, and future directions

Nosology, the classification of diseases or disorders, represents the systematic effort to organize diverse and complex clinical phenomena into meaningful and standardized descriptions of illness. In the field of psychopathology, the evolution of psychiatric nosology reflects the changing paradigms in our understanding of mental disorders. From the primordial attempts to categorize disorders based on spiritualistic perspectives to a more standardized approach influenced by clinical observations and scientific understandings. The 20th century witnessed the publication of the International Classification of Disease (ICD) and the Diagnostic and Statistical Manual of Mental Disorders (DSM), which have defined the constructs we study and treat for decades. Nevertheless, as the chapters in this book will no doubt serve to remind us, this journey is not without controversies and challenges. The inherent complexity and diversity of mental health conditions present difficulties in creating discrete categories that fully capture individuals’ experiences. Issues such as cultural variability and dynamic changes in mental health over time further complicate the task of constructing a reliable organization of psychopathology. Given the shortcomings of traditional classification systems like the ICD and DSM, the field has recently witnessed the emergence of alternative approaches to classification, such as the Hierarchical Taxonomy of Psychopathology (HiTOP; Kotov et al., 2017). The goal of this chapter is to briefly review important features of a useful nosology, describe the origin and structure of HiTOP, and discuss its implications for clinical practice, research endeavours, and the broader understanding of mental health within the context of an ever-evolving scientific landscape. Additionally, we will address some of the major criticisms of the quantitative approach to classification represented by HiTOP and describe ongoing efforts to address them.