An Exploration of Intervention Augmentation in a Single Case.

Recent work has highlighted that process-outcome relationships are likely to vary depending on the client, yet much work remains to be done in the area of tailoring interventions to a given client. This naturalistic single-case analysis provides an example of augmenting a treatment protocol with "off protocol" relaxation methods, based on routinely collected outcome information to guide shared decision making. Intensive case study analyses were applied to one client with principal generalized anxiety disorder and comorbid major depressive disorder receiving transdiagnostic cognitive-behavioral therapy. The client completed two routine anxiety and depression symptom and functioning scales prior to each session of naturalistic treatment. Time series analyses were applied to the two symptom measures. Among the results, (a) significant linear decreases in anxiety and depression from baseline to posttreatment were observed; and (b) the introduction of relaxation methods had a significant impact on the course of anxiety symptom change. In conclusion, routine outcome assessment can be used to inform intervention augmentation with individual clients. Furthermore, regular assessment is needed to determine if a client may benefit from an alternative set of specific intervention strategies.