Given the pervasive, debilitating nature of major depressive disorder, a large body of clinical research has evaluated the efficacy of short-term treatments for depression. Researchers have attempted to understand the complex mechanism of therapeutic change by examining treatment response, which is typically defined as the extent of symptom change between the intake and termination sessions. However, this approach fails to recognize that therapy is a non-linear, dynamic longitudinal process. An alternative approach involves analysis of longitudinal repeated measures process and outcome indicators in order to examine change both during treatment as well as following treatment. In order to evaluate dynamic, longitudinal hypotheses, it is necessary to use an appropriate analytical framework. A structural modelling technique termed Latent Difference Score Analysis (LDS) is well suited for this purpose, allowing for evaluation of longitudinal growth within a time series, while also considering multivariate relationships and determinants. / The purpose of this research was to evaluate established theories of depression vulnerability as well as theories of psychotherapy process, both during and following depression treatment. The research described in Chapter 2 examined several theories of the longitudinal relationship between depression and perfectionism during depression treatment, while considering the role of the therapeutic alliance. Longitudinal LDS analyses supported a "personality vulnerability" model of depression, in which perfectionism predicted the subsequent rate of depression change throughout treatment. Results indicate that patients with high levels of perfectionism experience less reduction in their depression scores throughout treatment. Furthermore, the strength of the therapeutic alliance significantly predicted the rate of change in personality vulnerability throughout therapy. The research described in Chapter 3 examined several theories of the longitudinal relationship between depression and stress following treatment termination. Results supported a "stress reactivity" model, in which stressful events led to elevations in the rate of depression change following therapy. Multigroup LDS analysis indicated that stress reactivity only occurred for patients who had been treated with medication, and not for those who had received psychotherapy. / These findings have several implications. First, comprehensive analyses of treatment efficacy can move beyond symptom reduction by examining mechanisms underlying treatment response using an appropriate statistical framework. The first paper demonstrates that an efficient route to symptom reduction involves establishing an adequate therapeutic alliance in order to target personality vulnerability. The second paper demonstrates that importance of evaluating treatment efficacy by considering whether a treatment leads to enduring change. Specifically, results indicate that the enduring effects of psychotherapy (in comparison to medication treatments) following treatment termination involves increased resiliency to stressful life events.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.102983 |
| Date | January 2006 |
| Creators | Hawley, Lance. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Psychology.) |
| Rights | © Lance Hawley, 2006 |
| Relation | alephsysno: 002591168, proquestno: AAINR32191, Theses scanned by UMI/ProQuest. |
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