Global health is an area for study, research and practice that places a priority on improving health and achieving equity in health for all people worldwide. Global mental health is the application of these principles to the domain of mental ill-health. The most striking inequity is that concerning the disparities in provision of care and respect for human rights of people living with mental health problems (MHP) between rich and poor countries. Low and middle income countries (LMIC) are home to over 80% of the global population, but command less than 20% of the share of the mental health resources. The consequent treatment gap is in itself a contravention of basic human rights. Even where treatment is provided, far too often this falls far below minimum acceptable standards. Failure to provide basic necessities such as adequate nourishment, clothing, shelter, comfort and privacy, and the administration of unauthorized and unmonitored detention, shackling and chaining are all well documented abuses, described recently as a failure of humanity. The emergence of the discipline of global mental health as one of the most dynamic fields of global health underscores the need for this textbook for students of the discipline. Global mental health was cited by the NIMH Director in his 2012 year-ending blog as one of the major advances in mental health in 2012 and by one of the most influential figures in psychiatry and anthropology, Arthur Kleinman, as the exciting future of academic psychiatry (Br J Psychiatry, December 2012). The scope of the book is to cover two major aspects of the field: its scientific foundations and its practice and opens with an original account charting the history of the field from antiquity to its most recent developments. The language and content is geared towards a wide audience of practitioners and students of global mental health, including those who do not have any previous training in a clinical mental health specialty. This textbook, edited by four of the fields most widely acknowledged champions, with 20 chapters authored by over 30 global leaders of the field from diverse institutions and countries, is aimed to be the definitive text of this dynamic new discipline.