Handbook of Psychology, Second Edition || Clinical PsychologyAUTHOR'S NOTE: The previous version of this chapter was co-authored by John M. Reisman, and I greatly appreciated the opportunity to collaborate with him at that time. He has, however, not participated in the revision, and I think it only fair to assume the role of sole author now. My wife, Margaret Gonzalez, has helped me make the revised chapter more clear and readable.