Electronic Thesis and Dissertation Repository


Doctor of Philosophy




Dr. David J. A. Dozois


Purpose: Researchers have recently demonstrated interest in interpretive bias, the tendency to interpret ambiguous information more negatively and/or less positively. The extent to which interpretive biases influence the occurrence of life stressors and potentially compound the negative effects of life stress in the development of depression is presently unknown. Hence, the purpose of this study was to investigate interpretive bias for ambiguous social information within the context of stress and depression. This study examined interpretive bias in the context of two theoretically and empirically supported models of depression – stress generation and diathesis-stress – to determine the mechanism through which interpretive bias influences depression. Method: Two hundred and seven young adult women participated in a two-wave prospective study. At Time 1, participants were asked to complete two measures of interpretive bias—the Scrambled Sentences Test and the Ambiguous Stories Task— as well as self-report questionnaires of their current depressive symptoms and depression symptom history. Five weeks later, participants were asked to complete a measure of their current depressive symptoms and a life events questionnaire. Results: Consistent with expectations, multiple indices of interpretive bias were directly predictive of Time 2 depression symptoms, over and above the effects of Time 1 symptoms. Some evidence was found for a role of interpretive bias in stress generation. In contrast to hypotheses, none of the interpretive bias variables interacted with life stress to predict depressive symptoms at follow-up (diathesis-stress model). Conclusion: Taken together, the findings suggest that a theoretically significant role exists for interpretive biases in depression vulnerability. Additionally, these findings offer initial evidence that individuals with a pre-existing cognitive vulnerability may be at risk of contributing to the occurrence of stressful life events in their lives. Future research should examine interpretive biases in the context of interpersonal behaviours to determine the specific pathways from interpretation of an ambiguous situation to stress generation and/or depression.

Pamela Seeds Dissertation.docx (524 kB)
Microsoft Word version of dissertation document