He is a psychiatrist, psychotherapist and professor emeritus at the University of Pennsylvania. Initially, he worked with patients in the psychoanalytic current, but discouraged by its directive nature and lack of evidence of effectiveness, he began to develop his own model of treatment. One of his areas of interest was depressive disorders: his triad and depression scale are now part of the canon of knowledge. Cognitive therapy has gained a very large number of adherents; it is also considered to be the most effective treatment for certain disorders (e.g. anxiety). Based on the original cognitive therapy, many new currents have emerged and new ones are still being created.