The outcome problem in psychotherapy: what have we learned?

The outcome problem in psychotherapy has usually been studied without much regard to the theories underlying the methods used. It is suggested that theories are vital to scientific advancement, and that without them we cannot even specify criteria to judge outcomes. Numerous studies since the 1950s have in essence failed to disconfirm the view that various forms of psychotherapy do not show greater effectiveness than spontaneous remission or placebo treatment. An effort is made to clarify the nature of spontaneous remission and placebo treatment, and to discuss the consequences of the many empirical findings and meta-analyses published over the past 50 years. A theory is suggested linking spontaneous remission, placebo treatment, psychotherapy and behaviour therapy, leading to a discussion of ethical considerations and cost-effectiveness issues.