Award Date


Degree Type


Degree Name

Master of Arts (MA)



First Committee Member

Andrew Freeman

Second Committee Member

Stephen Benning

Third Committee Member

Shane Kraus

Fourth Committee Member

Julia Freedman Silvernail

Number of Pages



Anhedonia, a cardinal symptom of a major depressive episode, is the decreased motivation to seek rewards. Individuals with depressive symptoms tend to report reduced positive affect, a distal measure of reward motivation, and engage in less reward-motivated behavior (i.e., reward seeking). However, diurnal rhythms may also influence reward-seeking. Both self-reported positive affect and behavioral measures of reward-seeking increase from the morning to the afternoon and then decreased in the evening. Therefore, the aim of this study was to examine whether reward-seeking varied across time of day and whether anhedonia moderated variation. Overall, reward-seeking did not vary across time of day. Diurnal trends in reward seeking may require within-subjects designs to detect individual variation over time. Additionally, anhedonia and depressive symptoms were not associated with reward seeking, nor moderated the relationship between reward seeking and the time of task completion. Risk taking may be too distal to reward seeking and anhedonia’s influence may be specific to rewards without salient risks. Exploratory results found cubic trends in certain measures of reward-seeking that may be a result of fatigue evoked by the study design.


Anhedonia; Circadian rhythm; Depression; Reward; Risk taking; Time of day


Mental and Social Health | Psychology

File Format


File Size

.857 MB

Degree Grantor

University of Nevada, Las Vegas




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