Personality as a Variable in Psychotherapy Research: Outcome or Process Measurement?

Psychotherapeutic effectivity research and personality research have developed in parallel ways. Nowadays, it is possible to identify two convergent perspectives: the study of the effect of the psychotherapy over personality change and the study of the effects of patients' personality variables over the psychotherapeutic process. In this paper some advances of process-outcome psychotherapy research, which includes personality as a variable, are shown. Specifically, the issue of personality change is presented and empirical studies, which include personality as an outcome or process measurement, are reviewed. The value of the concept of personality for psychotherapy research is discussed integrating theoretical, practical and methodological topics.