Undergraduate Honors Theses

Thesis Defended

Spring 2018

Document Type


Type of Thesis

Departmental Honors


Molecular, Cellular, & Developmental Biology

First Advisor

Dr. June Gruber

Second Advisor

Dr. Jennifer Martin

Third Advisor

Dr. Sona Dimidjian


Recent research has shown that emotional diversity – or the variety and relative abundance of the emotions one experiences – can be beneficial to one’s mental and physical well-being. However, it is less clear if cognitive behavioral therapy (CBT) – an empirically-supported and well-studied psychosocial treatment for depression – may impact emodiversity among adults diagnosed with major depression or experiencing symptoms of depression. To examine the potential clinical efficacy of CBT on emodiversity, the present investigation conducted a systematic review of the literature surveying a total of 87 studies and obtained full datasets from two CBT studies on depression in adults. Specifically, Study 1 included adults with major depressive disorder who were randomly assigned to receive either CBT (n = 70) or SSRIs (n = 22) and a non-psychiatric control group (n = 35), all of whom completed self-reported positive and negative affect before and after a 12-week treatment period (Siegle et al., 2012). Study 2 included adults (n = 41) treated with CBT naturalistically in private practice for depression and anxiety who completed weekly measures of positive and negative affect over a variable treatment period (Kring, Persons, & Thomas, 2007). Results suggested that CBT was effective in decreasing negative emodiversity among adults with a history of MDD or depressive symptoms (Study 1 and Study 2) and that CBT was associated with greater increases in positive emodiversity compared to SSRI among MDD adults (Study 1). Findings provide insight into affective mechanisms underlying empirically-supported treatments for depression.