James P. McCullough observed that patients with chronic depression show a deficit of operational thinking in interpersonal situations. Due to early emotional trauma, they get stuck in the preoperational stage of development according to Piaget. Specific techniques for psychotherapy of chronic depression will be described and illustrated by a case vignette. These techniques were first described by McCullough and labeled CBASP. The goal of these techniques is to teach formal operational thinking. In chronic depression, personal involvement techniques are a central element of successful therapy. With another interpersonal skills training technique called situational analysis, the patient learns to recognize the consequences of his behavior and behave in a goal-directed manner in interpersonal situations. Recent evidence on the effectiveness of CBASP will also be presented.