Evaluating new treatments in psychiatry: the potential value of combining qualitative and quantitative research methods

Abstract

Clinical trials have been extensively used in order to explore the effectiveness of drug treatments for psychiatric disorders. Double-blind, randomized controlled trials provide the potential to explore the effectiveness of treatments free from the effects of bias and confounding factors. More recently clinical trials have been used in order to evaluate the effects of more complex interventions such as psychological treatments and alternatives to inpatient treatment. Clinical trials of complex interventions present several methodological challenges including the need to identify their mechanisms of action, problems ensuring the fidelity of the experimental intervention and variations in the effects that interventions have in sub-groups of people. We argue that some of these challenges can be met by incorporating qualitative research methods into the experimental evaluation of complex interventions. The benefits and some of the problems of combining methods are illustrated by examples of recent and ongoing research.