When and why does cognitive-behavioural treatment appear more effective than psychodynamic-interpersonal treatment? Discussion of the findings from the Second Sheffield Psychotherapy Project

Abstract

The main outcome and process findings from the Second Sheffield Psychotherapy Project (SPP2) support the equivalence paradox: the overall outcomes of cognitive-behavioural (CB) and psychodynamic-interpersonal (PI) therapy were roughly the same, but the content of the two treatments were different. However, when we compared specific groups of clients or specific problems CB therapy showed an outcome advantage to PI therapy. Subsequent analyses of the data suggested that two factors accounted for these differences in treatment outcome and processes: the extent to which clients had assimilated their problems at the beginning of therapy and therapists' responsiveness to clients' interpersonal style. The implications of the SPP2 findings for clinical practice are discussed.