Definition and epidemiology of treatment resistance in psychiatry

The current chapter discusses different aspects of treatment resistance in mental disorders. We will first describe the prevalence and disease burden of mental disorders, then we will have a closer look at treatment outcomes in psychiatry, and next we will focus on treatment resistance, its impact and strategies for improvement. It will become clear that, despite the rapidly increasing knowledge base for psychiatric treatments, there are still many unknowns and points for improvement. The aim of this chapter is to introduce the major elements of this discussion needed to appreciate the more specific aspects that will be treated in the subsequent chapters that focus on specific disorders.</p