Originally, there was little scientific data to back up psychotherapists’ claims about the effectiveness of psychotherapy. People had to rely on the testimony of psychotherapists which, for many skeptics, was not particularly convincing. The empirical study of psychotherapy started in the 1950s, however, and within a few decades grew into a large movement. There now exists an entire field of psychotherapy research and there is substantial data supporting the positive effects of psychotherapy. Consequently, we can now state with confidence: Yes, psychotherapy does work.