There have been significant advances in the pharmacotherapy of depression in recent years. Clinicians now have available a broad range of efficacious and safe medications, which have been studied in randomized controlled trials and compared in rigorous meta-analyses. However, much remains to be understood about the pathogenesis of depression and about the mechanisms of action of antidepressants. In this nine-chapter book, renowned international experts have convened to address the different classes of pharmacotherapy currently available. In his opening chapter, the Editor provides some context