The Second Sheffield Psychotherapy Project: rationale, design and preliminary outcome data.

The cost-efficiency of psychotherapy research can be enhanced by (a) dissemination of the rationale and design of large-scale investigations whilst still under way, (b) incorporation of process measures within comparative outcome studies, (c) cumulative development of a series of related studies, and (d) sharing of recordings and other data with other investigators. We present the rationale and design, including full details of process and outcome measures, of the second Sheffield psychotherapy project, in which 120 white-collar, professional and managerial employees presenting with major depressive disorder receive either eight or 16 sessions of either prescriptive (cognitive/behavioural) or exploratory (relationship-oriented) therapy in a 2 x 2 design. Ethical considerations prompted the analysis of preliminary outcome data on 48 clients. Results suggested substantial clinical improvement, of similar magnitude for both methods and both durations of treatment, except that exploratory therapy appeared more effective than prescriptive in relation to interpersonal difficulties. Other workers are invited to build collaboratively on this research by making their own process analyses of recordings available from this study, relating these analyses to the existing impact and outcome data, and developing comparable data sets based on the design and initial results of this project.