Currently, a major issue within the psychotherapy literature is the specific/ nonspecific debate, which refers to the increasingly prevalent finding of equivalent treatment outcomes across diverse therapies, and the finding that cognitive change is not exclusive to cognitive therapies. Whilst CBT is undoubtedly efficacious in the treatment of depression and anxiety, there is continued debate concerning the mechanisms by which it exerts its therapeutic effects. One possibility is the operation of nonspecific factors that are hypothesised to play a significant role in change processes across the range of psychotherapies. Though the specific and nonspecific factors have been shown separately to impact positively on treatment outcome, further research is needed to address whether these aspects of therapy are mutually facilitative. Thus, the aim of this thesis was to examine the role of specific factors and the therapeutic alliance in change processes
associated with CBT for depression (i.e., Major Depressive Disorder) and anxiety (i.e., Panic Disorder and Generalised Anxiety Disorder). The empirical studies were conducted with an outpatient population.
Conceptualised as constituents of therapeutic alliance. Study 1 examined the nonspecific factors of client satisfaction with therapy and therapist, and a scale that measures these factors (i.e., Satisfaction with Therapy and Therapist Scale - Revised: STTS-R). An extension upon the work by Oei and Shuttlewood (1999), the study empirically evaluated the factor structure and psychometric properties of the STTS-R. EFA revealed two conceptually coherent factors which accounted for 66.9% of the variance. Consistent with Oei and Shuttlewood (1999), these factors were 'Satisfaction with Therapy' (ST) and 'Satisfaction with Therapist' (SWT). CFA revealed a 2-factor and total-score solution to be the best-fitting model. The STTS-R demonstrated good psychometric
properties and it was concluded that the scale would be useful in research as a measure of the nonspecific factors that operate in group CBT for depression and anxiety.
Study 2 extended upon the statistical procedures of Hartley and Strupp (1983) to empirically evaluate the factor structure of the Vanderbilt Therapeutic Alliance Scale - Revised (VTAS-R), and examine the psychometric properties of the scale. EFA revealed two conceptually coherent factors which accounted for 57.2% of the variance. Similar to those of Hartley and Strupp (1983) these factors were 'Positive Climate' (PC) and 'Therapist Intrusiveness' (TI). CFA failed to confirm any of the tested models as an adequate fit to the data, though revealed the new VTAS-R factor structures to be better-fitting than the original VTAS structures. Although the VTAS-R possessed good psychometric properties, further exploratory and confirmatory factor analyses were deemed necessary to ensure the underlying
structure was replicable and robust.
Study 3 investigated the phenomenon of specific and nonspecific factors in treatment outcome of group CBT for depression and anxiety. The variance that specific and nonspecific factors accounted for in the measurement of treatment outcome was examined, as well as the processes by which the therapeutic alliance facilitated the reduction of depression and anxiety. The outcome measures for the depression group included the Zung Self-Rating Depression Scale (ZSDS) and the Sentence Completion Test for Depression (SCD-22). The outcome measures for the anxiety group included the Beck Anxiety Inventory (BAI) and the Catastrophic Cognitions Questionnaire - Modified (CCQ-M). The STTS-R assessed the nonspecific factors of client satisfaction with therapy and therapist, whilst the VTAS-R assessed therapeutic alliance. Hierarchical regressions revealed that only the nonspecific factors significantly predicted change in level of
depression, whilst both the specific and nonspecific factors independently and significantly predicted change in level of anxiety. Although the causal relationship between these factors remains unclear, these findings were interpreted as consistent with the increasingly-popular proposition that the function of the therapeutic alliance in CBT is to facilitate the specific cognitive mechanisms of change. The empirical findings were summarised and the theoretical and clinical implications discussed. The necessity for further empirical investigation into the function of the therapeutic alliance in CBT was emphasised, together with recommendations for the manner in which future research may undertake such pursuits.