When one introduces a new psychotherapy model to professional colleagues, one must do 3 things: (a) define the patient for whom the program has been developed; (b) describe how the model addresses the problems of the patient, which entails some description of the techniques; and (c) present any efficacy data that are available that justify the usefulness of the new program with the target population. Accordingly, Part 1 of the article describes the chronically depressed adult, the target individual for whom the cognitive behavioral analysis system of psychotherapy (CBASP; J. P. McCullough, 1984McCullough, , 2001McCullough, , 2003a has been specifically developed. In Part II, the reader is shown how CBASP tries to modify the multiple psychopathological problems of the patient. In Part III is a summary of data obtained from a recently completed multisite, national clinical trial in which 681 chronically depressed outpatients were comparatively treated with CBASP, nefazodone (serzone), and their combination. Among completers of the study (n = 519; 76%) during a 12-week acute phase, 55% responded to serzone, 52% responded to CBASP, and 85% responded to combination treatment.