The inter-subjective and dialogical nature of narrative therapy, as commonly practiced, remains unarticulated. Further, there currently exists no rigorous empirical research investigating the process or outcome of narrative therapy. The research aim, to investigate the process and outcome of narrative therapy, comprised theoretical and empirical objectives. The first objective was to articulate a theoretical synthesis of narrative theory, research and practice. The process of narrative reflexivity was identified as a theoretical construct linking narrative theory with narrative research and practice. The second objective was to substantiate this synthesis empirically by examining narrative therapy processes, specifically narrative reflexivity and the therapeutic alliance, and their relation to therapy outcomes. The third objective was to support the proposed synthesis of theory, research and practice and provide quantitative evidence for the utility of narrative therapy, by evaluating depressive symptom and inter-personal relatedness outcomes through analyses of statistical significance, clinical significance and benchmarking. Founded in theories of self, language and narrative (James, 1890; Bruner, 1986; Gergen, 1991; Hollway, 2006; Vygotsky, 1934/ 1987), narrative therapy was conceptualized as involving dialogical and intra-personal processes. Narrative therapists generally apply a story metaphor and commonly focus on the inter-personal field (White, 2007). This thesis recognised the storied and inter-personal nature of narrative therapy, but proposed this does not represent narrative therapy in its entirety. The notion of story connotes monological processes, inconsistent with the conversations of narrative practice, and neglect of intra-personal dimensions is inconsistent with narrative notions of inter-subjectivity. This thesis proposed an integration of dialogical narrative theory (Cooper, 2003; Hermans & Kempen, 1993; Lysaker & Lysaker, 2006) and narrative research (Angus, Levitt, & Hardtke, 1999) provides a model for understanding narrative therapy (White, 2007) as involving the inter-subjective and dialogical process of narrative reflexivity. During the process of narrative reflexivity, a person engages in dialogue with his or her own self and others as extensions of self, interpreting experience from diverse perspectives in the context of personal aspects, such as beliefs, values and intentions that give meaning to experience, to achieve a rich narrative and a sense of well-being. To support this theoretical synthesis, a process-outcome trial evaluated eight-sessions of narrative therapy for 47 adults with major depressive disorder. Dependent process variables were narrative reflexivity (assessed at Sessions 1 and 8) and therapeutic alliance (assessed at Sessions 1, 3 and 8). Primary dependent outcome variables were depressive symptoms and inter-personal relatedness. Primary analyses assessed therapy outcome at pre-therapy, post-therapy and three-month follow-up and utilized a benchmarking strategy to the evaluate pre-therapy to post-therapy and post-therapy to follow-up gains, effect size and pre-therapy to post-therapy clinical significance. Results indicated that when a sub-sample of clients were categorised into five least-improved and five most-improved groups (according to depressive symptom change), there was a differential change in the percentage of reflexive sequences in the discourse of clients at the end of therapy depending on outcome. Improvement in the quality of the working alliance was associated with improvements in depressive symptoms and inter-personal relatedness, with working alliance improvement from Session 1 to 8 sharing 19% of the variance in depressive symptom improvement and 17% of the variance in inter-personal relatedness improvement from pre-therapy to post-therapy. The clinical trial provided empirical support for the utility of narrative therapy in improving depressive symptoms and inter-personal relatedness from pre-therapy to post-therapy: the magnitude of change indicating large effect sizes (d = 1.10 to 1.36) for depressive symptoms and medium effect sizes (d = .52 to .62) for inter-personal relatedness. Therapy was effective in reducing depressive symptoms in clients with moderate and severe pre-therapy depressive symptom severity. Improvements in depressive symptoms, but not inter-personal relatedness, were maintained three-months following therapy. The reduction in depressive symptoms and the proportion of clients who achieved clinically significant improvement (53%) in depressive symptoms at post-therapy were comparable to improvements from standard psychotherapies, reported in benchmark research. This research has implications for assisting our understanding of narrative approaches, refining strategies that will facilitate recovery from psychological disorder and providing clinicians with a broader evidence base for narrative practice. Despite limitations of a repeated-measures research design, use of a standardised intervention protocol, coupled with outcome evaluation of clinical significance enhanced internal validity. Future research could examine narrative therapy in a larger sample, with different disorders, and with an alternative therapy or control group. Coding a greater number of therapy transcripts for evaluating associations of narrative reflexivity with working alliance and outcomes could enhance understanding of narrative reflexivity. Thesis strengths included a strong theoretical foundation underpinning the research design and arguments, examination of therapy process in the context of outcome, and a parsimonious evaluation of narrative therapy outcomes.