This book provides a comprehensive review of melancholia as a severe disorder of mood, associated with suicide, psychosis, and catatonia. The syndrome is defined with a clear diagnosis, prognosis, and range of management strategies, differentiated from other similar psychiatric, neurological, and general medical conditions. It challenges accepted doctrines in the classification and biology of the mood disorders and defines melancholia as a treatable mental illness. Described for millennia in medical texts and used as a term in literature and poetry, melancholia was included within early versions of the major diagnostic classificatory systems, but lost favour in later editions. This book updates the arguments for the diagnosis, describes its characteristics in detail, and promotes treatment and prevention. The book offers great hope to those with a disorder too often mis-diagnosed and often fatal. It should be read by all those responsible for the management of patients with mood disorders.