Abstract
All psychotherapeutic methods must be scientifically evaluated. Empirical evaluation of evidence is a prerequisite for acceptance as scientific psychotherapy as well as for payment by health insurance. Currently the psychotherapy methods accepted within the German health system (behavioural therapy, psychodynamic psychotherapy, and analytic psychotherapy) are reviewed by a governmental evaluation committee concerning evidence, necessity and cost-effectiveness. The DPG practice study has basically two aims: 1) to conduct a large naturalistic study to investigate effectiveness, sustainability and economic aspects of psychodynamic and analytic psychotherapy and 2) to offer a framework for psychoanalytic institutes, members, candidates or groups to realize own research ideas by collecting additional data within the study. The present article describes the background, main research questions, structure and design of the DPG practice study with regard to the evaluation questions.