Treatment outcome evaluation methodology with anxiety disorders: Strengths and key issues

Methodology in the conduct of clinical outcome studies with anxiety disorders has advanced in several areas in recent years. Nevertheless, difficult issues concerning the conduct and interpretation of the results of these clinical trials remain. Developments that have facilitated clinical trials include the construction of structured interviews for anxiety and related disorders that allow consistency in identification of target disorders in a clinical context. An equally important development has been the introduction and widespread utilization of treatment manuals which allows for replicable independent variables. Remaining issues include ascertaining the optimal way of measuring change from among the variety of dependent variables available. A related difficulty is determination of the principle dependent variable (e.g., panic attacks, intrusive thoughts) in an anxiety disorder where many key features of anxiety disorders seem to coexist (symptom and syndrome comorbidity). Solving these issues as well as determining the optimal way to handle attrition will provide important methodological advances.