Examining Specific Cognitive Change in Cognitive Therapy for Depression: A Controlled Case Experiment

Abstract

Cognitive therapy (CT) is purported to ease depression primarily by weakening the influence of certain depressive beliefs. Customarily, this claim is supported by a reduced score on one or more of the standardized measures of dysfunctional thinking, and not by measuring beliefs specific to the individual; nor is it usual practice to monitor dysfunctional beliefs regularly before and throughout CT. The present single-case study describes a new approach for studying specific cognitive change by obtaining ongoing data on process and outcome. Multiple-baseline methodology was used to measure the impact of CT on four depressive beliefs identified during apre-baseline assessment stage. The patient, a man in his late 30s, was diagnosed according to Research Diagnostic Criteria (RDC: Spitzer, Endicott, & Robins, 1978) as having a primary depressive disorder which showed as moderate to severe on the Beck Depression Inventory (BDI: Beck & Steer, 1987). Anumberof measures of change were used, including weekly ratings of the degree of conviction with which the four beliefs were held, and the BDI was given at regular intervals. By the close of therapy, all beliefs were rejected and the BDI scores indicated that the client was asymptomatic. Validation of change was provided by an independent clinician who conducted pre- and post-assessment interviews, and via the Dysfunctional Attitudes Scale (DAS: Weissman & Beck, 1978); while this increased confidence that the reported changes were genuine, the limitations of the study are acknowledged. Maintenance over the six-month follow-up period was good. The study thus offers provisional evidence of specific cognitive change in CT, and describes a new methodology that could be used on a wider scale to reveal if cognitive change has primacy over symptom relief.