Client aptitude for cognitive behaviour therapy: the development and evaluation of a new measure

Submission note: Submitted in partial fulfilment of the requirements for the degree of Doctor of Clinical Psychology to the Department of Psychology and Public Health, School of Psychology and Counselling, La Trobe University, Victoria.

As an extension of Beck’s cognitive theory of psychopathology (Beck and Haigh, 2014; Beck et al., 1979) Cognitive Behaviour Therapy (CBT) proponents have theorised that change is enacted in CBT via cognitive change (Mennin, Ellard, Fresco, and Gross, 2013). Although clients arguably play the most important role in implementing this change process (Kazantzis, Dattilio, and Dobson, in press), research relating to individual differences and therapeutic change, which highlights the active role of clients, is limited (Bohart and Wade, 2013). The body of research conducted by the writer involved the development and subsequent psychometric evaluation of the Client Aptitude for Cognitive Behaviour Therapy (CACBT) observer scale, which was designed to examine client, in-session behavioural expressions of a range of cognitive abilities of posited relevance to CBT processes and outcomes. Grounded in the findings of the literature reviews that were conducted as a part of the present research, the CA-CBT scale assesses basic cognitive abilities, higher-order cognitive processes, aspects of emotional intelligence and interpersonal functioning Scale development and evaluation included thorough pilot testing and a stepped process of expert review, wherein 27 subject-matter experts provided feedback on a draft of the CA-CBT scale via an online questionnaire, using a process consistent with the Delphi method. In order to assess the development of the construct of interest over time, and its relationship to within- and post- treatment outcomes (i.e., next session and 0-, 6-, 12-, 18- , and 24- months follow-ups) the finalised CA-CBT scale was used to rate 49 early and 44 late sessions of a CBT for a depression condition from a previous component analysis (Jacobson et al. 1996). The results of this study indicated (i) that client aptitude significantly increased over the course of CBT, and (ii) that there were no significant relationships between early or late client aptitude and within- and post- treatment outcomes, after controlling for depression symptomatology and after accounting for multiple comparisons.