Reported by the WHO and the World Bank to be the fourth cause of disability worldwide, depression can best be explained from a genetic perspective as a complex disorder of gene-environment interactions. This is the first major reference to cover the clinical aspects of this common and complex disorder of unknown cause. Readers will also learn about our current understanding of the psychosocial, environmental, biological, and genetic aspects of depression. The authors are internationally recognized experts from leading academic and industrial environments, and they present the features, advantages, and limitations of animal models while reviewing candidate biological systems and genetic approaches. In addition, the book covers the important topic of the medical consequences of depression, as clinicians and investigators increasingly appreciate how it negatively impacts on cardiovascular function and bone mineral density. Finally, a separate section is devoted to the biochemical and molecular basis for existing treatments, along with strategies for the use of genomic tools to discover new targets for antidepressants and to predict therapeutic outcomes.