This introduction presents an overview of the key concepts discussed in the book Mental Health and Disasters. The book is the definitive reference on mental health and disasters. It focuses on the assessment and treatment of the full spectrum of psychopathologies associated with many different types of individual disasters. The book talks about the mental health consequences of disasters. It provides a synthesis of the current knowledge of the mental health effects of disaster. The book focuses on key aspects of vulnerability and resilience in the face of disasters. It overviews the scientific literature on the key known determinants of the mental health consequences of disasters. The book discusses the science of interventions after disasters, along with the barriers and challenges faced in providing mental health care services after these events. It presents detailed explorations of a number of sentinel natural, technological, and human-made disasters.