This chapter describes the two most common emotional disorders: depressive and anxiety neuroses. It discusses how symptoms of depression and anxiety tend to cluster together into different categories; and how a psychological understanding has helped in the development of new treatments. Anxiety and depression are a part of everyday living. It is only when they persist and become more severe that they cause problems for people or their families. Many attempts have been made to identify different types of depression. In order to deal effectively with depression, it is important to know what psychological factors may be causing and maintaining it. Anxiety, like depression, is a normal part of everyday life for the majority of people. Generalized anxiety disorder is usually characterized by severe and disproportionate worry about life issues which persists more or less consistently for 6 or more months. Panic disorder is a more extreme form of anxiety than that found in generalized anxiety disorder.