What do we know about highly effective therapists? A systematic review

Highly effective therapists are clinicians who systematically achieve excellent therapeutic outcomes. Although these types of therapists can be found among different therapies, the variables that could explain their performance remain uncertain. Therefore, to clarify these variables, analyze their definition, their objective measures, and the extent to which they measure what they claim, a systematic review (SR) was conducted. Publications between 2000 and 2020-from Scopus, MEDLINE/PubMed, Web of Science, PsycInfo, Google Scholar and ProQuest Research Library databases-were included. After analyzing 2784 empirical works, 31 studies have met the inclusion criteria. The results made it possible to identify, summarize and define almost 50 predictor variables of therapist effect. The need to increase construct validity, to improve empirical designs and to measure therapist-client interaction is discussed.