Do chronically depressed individuals exhibit a hostile-submissive interpersonal style and what is the process of change in Cognitive Behavioural Analysis system of psychotherapy?
Cognitive Behavioural Analysis System of Psychotherapy (CBASP) has been developed to treat individuals suffering from chronic depression. There is a growing evidence base to suggest that CBASP is effective for these individuals. Given these findings, it is important to understand the process of change during CBASP and how it is affected by the components of the therapy. Purpose: A systematic review and meta analysis aimed to establish whether there is evidence for one of the theoretical foundations of CBASP; that a hostile-submissive interpersonal style is associated with major depressive disorder, and in particular with chronic forms of depression, as suggested by McCullough (2000). An empirical study then aimed to investigate whether the components of CBASP are associated with symptom change for chronically depressed individuals during therapy. It also sought to examine whether individuals experienced change differently in CBASP if it was delivered without using Disciplined Personal Involvement (DPI) by the therapist. The aim of this research was to investigate the process of change within the context of CBASP for individuals receiving the therapy, and to evaluate the usefulness of a multilevel modelling approach to analysing singe-case data. Methods: The literature was systematically searched for research reporting a relationship between depression and interpersonal hostility and/or submissiveness and a meta-analysis conducted to test the strength of this relationship. An empirical study presents analyses of two datasets. The first is a multilevel modelling analysis of data from a CBASP case series, seeking to determine what role the components of CBASP have in symptom change during therapy. A single-case, multiple baseline study then examined the process of symptom change during CBASP. This study included individuals experiencing chronic depression, who completed a series of baseline observations followed by up to 20 sessions of CBASP over a six-month period. Participants were assigned to either receive manualised CBASP, or a form of CBASP without the interpersonal focus. The latter study employed mixed models to evaluate change in individuals in CBASP, and sought to evaluate this novel approach to single-case analysis. Results. The meta analytic review provided preliminary support for McCullough’s (2000) hypothesis that chronically depressed individuals tend to present as more hostile and submissive than individuals with first-episode MDD. Findings from the empirical study suggest that acquisition learning in relation to the situational analysis exercise in CBASP is associated with symptom change but not learning in relation to the interpersonal discrimination exercise. Findings from the single-case analysis, however, provided limited evidence that CBASP without the interpersonal focus is associated with less change over the first few sessions of therapy than CBASP. Multilevel modeling analysis of single cases appeared to provide a useful approach to evaluating within-individual change in therapy, compared with traditional methods such as clinically significant change indices. Discussion: The findings of this thesis provide preliminary evidence for components of McCullough’s (2000) CBASP model. The review’s results pointed to a need for more methodologically sound studies to further investigate the role of interpersonal style in the aetiology and maintenance of chronic depression. Analyses in the empirical study appeared to support the use of Situational Analysis in bringing about symptom change in therapy, but findings were mixed in relation to the interpersonal components of CBASP. The use of a small-N design with multiple baselines allowed for a preliminary analysis of the role of DPI, but incomplete data limited this analysis to the first half of therapy.