[Clin Psychol Sci Prac 18: 89–99, 2011]
The meaning of the term evidence-based psychotherapy (EBP) is a moving target and is inconsistent among international organizations. To clarify the meaning of EBP and to provide guidelines for evaluating psychosocial interventions (i.e., psychological treatments), we propose that psychotherapies should be first classified into nine categories, defined by two factors: (a) theory (mechanisms of psychological change) and (b) therapeutic package derived from that theory, each factor organized by three levels: (a) empirically well supported; (b) equivocal data [(a) no, (b) preliminary data less than minimum standards, or (c) mixed data]; and (c) strong contradictory evidence. As compared to the previous classification systems, and building on them, we add the requirement that there should also be a clear relationship between a guiding theoretical base and the empirical data collected. The proposed categories are not static systems; depending on the progress of research, a form of psychotherapy could move from one category to another.