Open Collections

Terpstra, Alexander Roy

University of British Columbia

For this dissertation, I examined anticipatory reward sensitivity, facial emotion judgment, and self-referential processing in major depressive and bipolar spectrum disorders (MDD and BSD) during a major depressive episode (MDE). I also examined whether these cognitive-affective processes predicted trajectories of response to repetitive transcranial magnetic stimulation (rTMS) for treatment-resistant depression (TRD) and/or changed from pre-treatment to post treatment. In Chapter 1, I begin by conceptualizing the constructs of interest and reviewing previous research relevant to MDD and BSD as well as rTMS for TRD. I subsequently introduce my research questions and hypotheses. In Chapter 2, I report a study examining differences in the cognitive-affective processes of interest between acutely depressed individuals with MDD and BSD, as well as non-psychiatric control participants (NCs). I show that individuals with MDD exhibited blunted anticipatory reward sensitivity and attributed fewer positive traits to themselves compared to individuals with BSD and NCs. Participants with BSD also self-attributed fewer positive traits than NCs. Individuals with MDD and BSD attributed more negative traits to themselves and had greater negative self-referential memory bias than NCs. Thus, anticipatory reward sensitivity and self-attribution of positive traits may be higher in BSD than MDD, and self-attribution of negative traits and negative self-referential memory bias appear higher in both disorders, compared to NCs. Chapter 3 is a study examining the roles of reward sensitivity, facial emotion judgment, and self-referential processing in response to rTMS for TRD. I found that anticipatory reward sensitivity and the number of negative traits participants self-attributed at baseline were significantly associated with overall depressive and suicidality symptoms, from baseline to three months post treatment. Furthermore, participants self-attributed a higher number of positive traits and a lower number of negative traits, and had lower negative self-referential memory bias, at one-week post rTMS compared to baseline. The findings suggest baseline reward sensitivity and negative self-referential processing may be risk factors for higher depressive symptoms and suicidality during and after rTMS. Additionally, rTMS may help address negatively biased self-referential processing. In Chapter 4, I conclude with a final summary and discussion of this research, including limitations and future directions.

Text

2023-08-31

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/85721

Psychology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/