Depression is a major cause of morbidity throughout the world. Given that between 8 and 12% of the population (in most countries) will suffer from depression at some point in their lives, it is clearly a significant public health problem. As our knowledge of this illness has expanded in recentyears, it has become clear that depression can no longer be viewed as a simple disorder of the brain. It has to be seen as a series of behavioural and biological changes that span mind, brain, genes, and body - indeed affecting both psychological and physical health. This book brings together world leaders in research on depression, to discuss, for the first time, in an interdisciplinary setting, both classical and innovative ideas to understand this devastating disorder. It presents neurobiological, psychological, genetic and evolutionary models, with aparticular emphasis on the mechanisms linking the brain to the endocrine and the immune systems, and therefore linking depression to physical health. Opening with a powerful, personal, account of depression, that conveys something of the all-consuming, debilitating, nature of this illness, the book then presents cutting edge research from those at the frontiers of work in this area. The book will be valuable for all those in the brain sciencesseeking a state of the art review of this global problem.