During the past year depression has remained an important theme of debate in Britain because of its continued high prevalence and association with suicide. Nonetheless patients are often inadequately assessed, the diagnosis is frequently missed, and treatment is commonly inadequate. Depression also has a complex aetiology and physical causes including several medical conditions are often causally related. The condition has a devastating effect on an individual's life and without adequate treatment can be disabling. The following papers examine some of these issues in detail.