Group Processes in Group Cognitive-Behavioural Therapy: An Investigation of Their Therapeutic Importance in Patients with Mood Disorders or Anxiety Disorders

Existing literature has conclusively shown that group cognitive behavioural therapy (GCBT) is effective and efficacious for a variety of mental health disorders and physical health issues. With such overwhelming support, the question is no longer whether GCBT works, but what makes it works. Increasingly, experimental attention is now centred on understanding the mechanisms underlying these positive treatment outcomes. One possible mechanism of change is that of group processes. Relatively little attention has been given to the unique properties of the group format, as important vehicles for treatment process and outcomes. Clinical studies which have examined group processes typically focus on the notion of cohesion. This thesis seeks to address the existing gaps in the group psychotherapy literature by investigating the role of group process variables in influencing therapeutic outcomes, and in particular, GCBT. This was achieved through extending investigation beyond cohesion to include other potentially important group process variables, validating group process instruments in clinical samples, incorporating a wide range of treatment outcome measures (specifically using symptomology measures, quality of life and global functioning measures, and self- and clinician-rated measures) and making comparisons across two diagnostic groups (mood disordered patients and anxiety disordered patients) in a real-life clinical group setting. Chapter 1 provides an overview of the current evidence for GCBT and in particular, the efficacy of GCBT in the treatment of mood and anxiety disorders. It then discussed the concept of mechanisms of change in psychotherapy by differentiating between specific factors and non-specific factors. Group process factors, as a non-specific factor, were highlighted as a relatively under-researched but essential component in understanding the contributing components of therapeutic gains. “Cohesion” had been the main construct of investigation by group processes researchers. However, in recent years, investigators have cautioned the unequivocal importance placed on cohesion, citing difficulties in reaching a theoretical agreement of the construct, measurements and conflicting evidence of its proposed benefits on clinical outcomes. As such, a case for considering other less examined but potentially important group process factors for group psychotherapy was put forth. These factors, specifically Expressiveness, Independence, Autonomy, Task interdependence and Homogeneity, were selected after consulting other branches of psychology (e.g. social psychology) which have more established knowledge about small group phenomena. Because of their potential significance in effecting benefits in group psychotherapy, investigation into the role of these group processes factors is proposed. Chapter 2 comprised of a study with two parts, focusing on the constructs of cohesion, expressiveness and independence. The study examined the psychometric properties of three group processes scales (i.e. Feelings about the Group Scale and Gross-Yalom and Rand Cohesion Questionnaire in the first part of the study and three subscales of the Group Environment Scale in the second part of the study). Exploratory factor analyses with these three measures demonstrated moderately consistent factor structures with the original measures but with revised item loadings for the current sample. Internal consistencies for the total scales and the factor scales of the three measures varied. Effectiveness of the group programme was evidenced by significant positive changes in treatment outcome measures and effect sizes of small to medium were obtained across most measures. Further analyses using bivariate correlations and multiple regressions were conducted to investigate the relationships between group process factors and treatment outcomes for patients who completed the GCBT. Collectively, results suggested that cohesion may be more important in GCBT for depression while expressiveness may be more significant for GCBT for anxiety. In addition, group processes seem to exert their influence differentially across the two clinical groups. Independence seemed to be related to negative outcomes for the Anxiety group. Findings were discussed within the context of psychometric issues, differences between diagnostic groups, clinical implications and research limitations. Chapter 3 investigated the role of other less investigated group process factors (i.e. Autonomy, Task Interdependence, Expressiveness and Homogeneity) in predicting treatment outcomes. As there was no established group process scale which measured these variables of interest within a clinical population, a new scale was first developed and validated in the current study. As expected, four factors, representing the four group process variables were obtained in the exploratory factor analyses. A similar set of analyses, as that performed in Chapter 2, was carried out. Results suggested that Autonomy played the most important role in contributing to clinical outcomes while Task Interdependence, Expressiveness and Homogeneity appeared to exert limited significant influence. In addition, differential effects of group processes were found for the two diagnostic groups. Theoretical, research and clinical implications were discussed. The final chapter sought to consolidate the findings of the two studies conducted. Complexity of the findings was highlighted. Theoretical, research and clinical implications, as well as limitations and directions for future research, were also discussed