The meaningful assessment of therapy outcomes: Incorporating a qualitative study into a randomized controlled trial evaluating the treatment of adolescent depression.

For many years, there have been heated debates about the best way to evaluate the efficacy and effectiveness of psychological therapies. On the one hand, there are those who argue that the randomized controlled trial (RCT) is the only reliable and scientifically credible way to assess psychological interventions. On the other hand, there are those who have argued that psychological therapies cannot be meaningfully assessed using a methodology developed to evaluate the impact of drug treatments, and that the findings of RCTs lack "external validity" and are difficult to translate into routine clinical practice. In this article, we advocate the use of mixed-method research designs for RCTs, combining the rigor of quantitative data about patterns of change with the phenomenological contextualized insights that can be derived from qualitative data. We argue that such an approach is especially important if we wish to understand more fully the impact of therapeutic interventions within complex clinical settings. To illustrate the value of a mixed-method approach, we describe a study currently underway in the United Kingdom, in which a qualitative study (IMPACT-My Experience [IMPACT-ME]) has been "nested" within an RCT (the Improving Mood With Psychoanalytic and Cognitive Behavioral Therapy [IMPACT] study) designed to evaluate the effectiveness of psychological therapies in the treatment of adolescent depression. We argue that such a mixed-methods approach can help us to evaluate the effectiveness of psychological therapies and support the real-world implementation of our findings within increasingly complex and multidisciplinary clinical contexts.