In this chapter, we will briefly review evidenced-based approaches to understanding and treating mood disorders. For greater depth, we have included along with references, hyperlinks to other materials. In other chapters, we will begin by looking at the evidence for the pros and cons of various medications and then we will do the same for psychotherapeutic interventions. Succeeding chapters will consider combination therapies, alternative and complementary therapies, and attempts at self-medication to ease the distress.