This book reviews all the important aspects of treatment-resistant psychiatric disorders, covering issues such as definitions, clinical aspects, neurobiological correlates, treatment options, and predictors of treatment response. The book is divided into three sections, the first of which examines the most recent thinking on treatment resistance in psychiatry, including definition and epidemiology, paradigm shift in the study of the subjects, individual susceptibility and resilience, abnormal structural or functional connectivity, and insights from animal models. The second section then discusses treatment resistance in each of the major psychiatric disorders, with particular focus on the responsible clinical and biological factors and the available management strategies. Finally, more detailed information is presented on diverse pharmacological and non-pharmacological therapeutic interventions. The book, written by leading experts from across the world, will be of value to all who seek a better understanding of the clinical-neurobiological underpinnings and the development of management for treatment resistance in psychiatric disorders.