ABSTRACT
Mental health practice is composed of a large variety of interventions. These range from admission to a psychiatric ward to participation in a self-help group or taking a course of psychotropic medication. In relation to any of these, it seems reasonable and indeed socially important to ask, ‘Does it work?’, or ‘Does intervention X work better than intervention Y?’. This chapter sets forth the basic principles of outcome research, which lies at the heart of efforts by clinical psychologists and others to build a scientific foundation for mental health practice. The aim is to provide a guide both to the design of outcome studies and to the critical reading of published outcome research, Examples will be taken from research on psychological treatments, because this is the field I know best. However, most of the principles discussed are common to all mental health interventions. Indeed, the basic research approach or paradigm of outcome research was originally developed for the evaluation of drug treatments.
