ABSTRACT
An evidence-based approach to the practice of psychotherapy requires that some basic questions about the nature of therapy be addressed. Evidence-based practice can only be as good as the research on which decisions are to be made. The difficulty in providing an adequate evidence base for at least some of the modes of psychotherapy has been discussed extensively elsewhere (Roth and Fonagy, 1996; Aveline and Shapiro, 1995; Parry and Watts, 1996; Bergin and Garfield, 1994). Within this volume there are several commentaries about the nature of evidence itself (see Chapters 1 to 6).
