Ilardi, Stephen SElliott, Brendon2024-11-262024-11-262022-12-312022http://dissertations.umi.com/ku:18760https://hdl.handle.net/1808/35727Key features of the dynamic interrelationship between acute depressive illness and more enduring trait-like constructs, such as personality and interpersonal style, remain unclear. Notably, self-reported changes in patients’ personality traits during depression treatment are amenable to competing conceptualizations, including the position that the presence or absence of severely negative mood may bias the self-reporting of theoretically stable constructs. The purpose of this study was to examine the degree to which a brief intervention for depression – either cognitive-behavioral or interpersonal therapy – would be associated with significant changes in self-reported pathological personality traits (PID-5-SF) and interpersonal problems (IIP-SC), and to determine whether or not such changes would remain significant in models accounting for changes in patients’ dysphoric mood and other depressive symptoms from pre- to post-treatment. Linear mixed-effects models with random intercepts were used to test for changes during treatment, and subsequent sets of models controlled for the effects of Dysphoria Neurovegetative Symptoms, which were derived from a factor analysis of the Montgomery- Asberg Depression Rating Scale (MADRS). During treatment, all PID-5-SF domains significantly decreased (p < .05). The severity of interpersonal problems also significantly decreased, but no change was observed in participants’ interpersonal style dimensions (Agency and Communion). None of the changes over time remained significant in models controlling for the effects of Dysphoria, nor in models that included Dysphoria and Neurovegetative factors in tandem. However, Dysphoria remained a significant predictor of in-treatment change on several personality traits and interpersonal difficulties, even in models that included the effect of Neurovegetative Symptoms. These results largely support the mood-state dependence hypothesis and suggest that self-reporting of long-term maladaptive traits may not be reliably assessed in depressed populations.42 pagesenCopyright held by the author.Clinical psychologycognitive-behavioral therapydepressioninterpersonal problemsinterpersonal therapymoodpersonalityThesis0000-0003-3682-8419