Randomized controlled trials (RCTs) are currently the dominant methodology for evaluating psychological treatments. They are widely regarded as the gold standard, and in the current climate, it is unlikely that any particular psychotherapy would be considered evidence-based unless it had been subjected to at least one, and usually more, RCTs. Despite the esteem within which they are held, RCTs have serious shortcomings. They are the methodology of choice for answering some questions but are not well suited for answering others. In particular, they seem poorly suited for answering questions related to why therapies work in some situations and not in others and how therapies work in general. Ironically, the questions that RCTs cannot answer are the questions that are of most interest to clinicians and of most benefit to patients. In this paper, we review some of the shortcomings of RCTs and suggest a number of other approaches. With a more nuanced understanding of the strengths and weaknesses of RCTs and a greater awareness of other research strategies, we might begin to develop a more realistic and precise understanding of which treatment options would be most effective for particular clients with different problems and in different circumstances.
KEY PRACTITIONER MESSAGE: Practitioners can think more critically about evidence provided by RCTs and can contribute to progress in psychotherapy by conducting research using different methodologies.