Developing reliable and valid assessments of techniques in cognitive behaviour therapy for depression

Submission note: A thesis submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy to the Department of Psychology and Counselling, School of Psychology and Public Health, La Trobe University, Bundoora.

Depression is one of the most highly prevalent and debilitating psychological disorders. Research suggests that Cognitive Behaviour Therapy (CBT) is a highly effective treatment for individuals with depression. Despite the increasing practice of CBT, there exist a number of attitudes towards CBT that may hinder the dissemination of the approach. For example, one such opinion is that CBT is defined by its techniques rather than the theoretical framework. These misconceptions have been noted among proponents of CBT, and are also reflected in psychotherapy research, where techniques are the most common form of identifying CBT and measuring adherence to CBT in clinical trials. This thesis presents the development of a reliable and valid measure of techniques in CBT. Study 1 was a qualitative study of 2,086 mental health practitioners from diverse training and occupational backgrounds that examined: (a) the CBT techniques they incorporate into their practice, (b) how they report using these techniques (e.g., to target cognitive change), and (c) their opinions of CBT and its associated techniques. Study 2 involved the development of the Cognitive Therapy Orientation Scale (CT-OS), a process scale that measures: (a) CBT techniques, (b) the cognitive change processes of each technique, and (c) the level of clarity/ skill with which these cognitive change are discussed with the client. A total of 191 archived sessions from a previous randomized controlled trial on CBT for depression were rated with the CT-OS. Data were examined in relation to therapeutic change throughout treatment, at outcome, and at 6-, 12-, 18-, and 24-months follow-up. Results from Study 1 revealed that mental health practitioners often use CBT techniques without considering the theoretical framework of the approach. The qualitative analysis provided insight into how CBT techniques are typically used among mental health practitioners, and which techniques are commonly incorporated into their practice. Study 2 found that the degree to which techniques and cognitive change processes were addressed in treatment was a significant predictor of treatment outcome. The present research highlights the importance of how techniques are defined and measured in CBT, and demonstrates a number of cognitive change processes that lead to significant clinical change within clients.