One size cannot fit all: A stage model for psychotherapy manual development

There has been controversy surrounding the roles and value of psychotherapy manuals in clinical practice since their inception. It has been underrecognized that the appropriate,roles and content of manuals should evolve with the stage of development of a given treatment. This article proposes a stage model in which manuals are seen as evolving with the level of development of the treatment, from the basic outlines necessary for preliminary evaluation of the treatment in early pilot studies (stage I), to highly defined guidelines that demark the internal and external boundaries of treatment for efficacy studies (stage II), and finally to elaborated systems appropriate for use with diverse clinical populations (stage III). We propose guidelines for the content of manuals at the various stages, as well as strategies for developing "clinician-friendly" manuals to facilitate broader use of empirically supported treatments.