Relationship factors such as a psychotherapy group's cohesion and interpersonal climate have been touted as being analogous to the therapist-client alliance in individual psychotherapy, and as such should predict treatment outcome. However, predicting and explaining contributors to outcome in group psychotherapy remains unclear. This series of studies examined therapist-client alliance, group cohesion and climate, self-other differentiation processes (using a repertory grid method) and mastery of Core Conflictual Relationship Themes (CCRT) in brief dynamic group therapy for depression. These studies also integrated qualitative-phenomenological and clinical-quantitative research methodologies to examine in detail significant helpful and hindering psychotherapy events. It was found that therapeutic alliance is not analogous with group cohesion, but is associated with group member's engagement in therapeutic tasks. Perceived levels of conflict and group developmental processes helped explain the dimensions of cohesion. How group members defined themselves in relation to others meaningfully changed over therapy. Changes in perceived conflict in the group, and an individual's mastery of their CCRT patterns predicted outcome. In particular, through the experience of telling their stories, clients were able to change their responses to conflicts both within the group and in their wider interpersonal circle.