Where Are the Commonalities Among the Therapeutic Common Factors?

Abstract

There is little convergence or empirical research on factors shared by diverse psychotherapies. We reviewed 50 publications to discern commonalities among proposed therapeutic common factors. The number of factors per publication ranged from 1 to 20, with 89 different commonalities proposed in all. Analyses revealed that 41% of proposed commonalities were change processes; by contrast, only 6% of articulated commonalities were client characteristics. The most consensual commonalities across categories were development of a therapeutic alliance, opportunity for catharsis, acquisition and practice of new behaviors, and clients' positive expectancies. The frequency of selected commonalities is presented and directions for future research are outlined.