Stress, Mental Health, and Their Role in Reward-Based Decision-Making
Have you ever been to a carnival and played a dart-throwing game? If you throw darts and win, you can get a smaller prize immediately or you can take additional turns to save for a larger prize in the future (e.g., the big teddy bear on the shelf). This is an example of an intertemporal choice, or a choice between rewards available at different times.
One well-known phenomenon associated with intertemporal choices is delay discounting, or temporal discounting. Delay discounting refers to people’s tendency to choose an immediate reward instead of waiting for a later reward, even when the later reward is larger in value. Experiencing stress about your financial situation or life may increase how impulsive you are when deciding between immediate and future rewards, and this can impact your future. Discounting more could lead to unhealthy choices and financial issues, like problems with gambling. Therefore, discovering more about the kinds of people or situations that lead someone to make more impulsive decisions is important to the field of psychology, because knowledge of this can help us find or create more solutions to help people. In this study, which was funded by a Summer Undergraduate Research Fellowship (SURF) from the Hamel Center for Undergraduate Research, Dr. Jolie Wormwood and I examined how stress and mental health symptom severity are related to college students’ choices between immediate and future rewards.
Data Collection
This study was approved by the University of ʤ Institutional Review Board (IRB) under protocol number IRB-FY2024-263. We recruited 120 participants from Prolific.com, an online platform for participant recruitment and remuneration. Eligible participants were currently residing in the United States, enrolled in an undergraduate degree program, and fluent in English. Participants’ ages ranged from eighteen to fifty years old. They identified their gender and race (see Figure 1). Three participants were removed from analyses because their delay discounting scores were outliers (i.e., fell outside the expected distribution of values).
Figure 1. Demographic characteristics of study participants.
Participants completed the study remotely via Qualtrics on their personal computer in a single online session lasting approximately twenty minutes. After providing informed consent, participants completed the Temporal Discounting Task (described below). After the task, participants completed the self-report questionnaires (described below) and received a debriefing form. Participants received four dollars for completing the study.
Participants were told that past work suggests listening to music helps people focus on tasks, and they were randomly assigned to complete the Temporal Discounting Task while listening to one of two pieces of music. One piece of music was meant to be calm and relaxing (Violin Concerto No. 4 in D Major, KV218, Mvt 2 by Mozart) and served as our control condition. The other piece of music was loud and discordant and was meant to be stress-inducing (“Night Flight,” Exorcist II, by Ennio Morricone). Participants listened to their assigned piece of music for three minutes before completing the Temporal Discounting Task.
The task itself involved twenty-seven decisions between choosing smaller cash amounts ($11 to $80) available immediately or larger amounts ($25 to $85) available in the future, from one week to six months later. Participants’ choices in the task were used to estimate a discount rate for each participant. Higher discount rates indicated greater impulsivity or impatience (i.e., stronger preference for more immediate rewards).
We also measured individual differences in anxiety and depression symptom severity, and trait stress (i.e., perceived average exposure to stressors). Trait stress was assessed using several scales from the Adolescent Stress Questionnaire (ASQ; Byrne et al., 2007). Participants rated how stressful they found each of several items over the past year on a five-point scale ranging from 1, “not at all stressful,” to 5, “very stressful.” Specifically, participants answered five items about each of the following: stress related to school and leisure, financial stress, and the stress of having adult responsibility.
To look at participants’ mental health symptom severity, we used the Generalized Anxiety Disorder-7 scale (GAD-7; Spitzer et al., 2006), which assesses anxiety symptoms. Participants reported how often they were bothered by a list of symptoms over the previous two weeks (e.g., “feeling nervous, anxious, or on edge” and “trouble relaxing”) on a scale from 0 (not at all) to 3 (nearly every day). For depression symptom severity, we used the Patient Health Questionnaire-8 (Kroenke et al., 2009). Again, participants reported how often they were bothered by a list of symptoms over the previous two weeks (e.g., “little interest or pleasure in doing things” and “feeling down, depressed, or hopeless”) using the same scale. For each scale, the responses to the individual items were summed to give a single score of anxiety and depression symptom severity, respectively.
Using these measures, we examined how stress and mental health are related to decision-making in contexts involving choices between immediate and future rewards, and we predicted participants would have higher discount rates (i.e., be more impulsive) when they were experiencing stress or when they had higher trait stress or mental-health-related distress.
Preliminary Findings
We found that participants who listened to stressful music reported feeling significantly more stressed and less pleasant than those in the calm music condition, suggesting the music did indeed increase acute feelings of stress during the task. Participants who listened to stressful music also had a higher discount rate than those who listened to calm music, consistent with our predictions, but this difference was not statistically significant. Also consistent with our predictions, we found that current self-reported stress predicted significantly higher discounting, though only in the calm music condition. This may be because people in the stressful music condition generally all reported high levels of stress, which may have prevented us from looking at how different stress levels were associated with discounting within that condition. Contrary to predictions, we did not see any associations between discounting rates and mental health (depression and anxiety symptom severity) or trait stress.
One reason we may have failed to find any significant associations between discounting rates and mental health is that our sample was recruited online from the general public, and participants did not disclose if they had a mental health diagnosis. However, we did see a wide range in self-reported symptom severity even in this sample: Approximately 38% and 31% of participants reported low or no anxiety and depression symptoms, respectively, and approximately 17% and 14% of participants reported moderate or severe anxiety and depression symptoms, respectively.
In supplemental analyses, we also found that anxiety and depression symptom severity were significantly positively associated with our measures of trait stress related to financial pressure, school/leisure conflict, and adult responsibilities. These findings demonstrate how these stressors play a role in mental health and well-being even if they are not associated with delay discounting.
This SURF project contributed to my long-term goal of becoming a professional researcher focusing on behavior and what affects the neurobiology of Alzheimer’s disease. It also enhanced my understanding of human psychology and behavior within a college population. Looking into delayed discounting broadened my knowledge of how people approach simple and complex decisions in life, as well as how stress and mental health symptomatology can impact risk-taking and decision-making behaviors. I plan to read more on delay discounting and behavior among undergraduate students specifically and would like to discover more about what impacts mental health in the undergraduate population and within neurodivergent individuals.
I would like to thank my mentor Jolie Wormwood and Alix MacVittie for their willingness to spend so much time going back and forth, cheering me on, and guiding me along the way for something that meant so much to me. I am grateful for the support from the Hamel Center for Undergraduate Research and my donors, Mr. Dana Hamel, the ʤ Parents Association Undergraduate Research Fund, and the Class of 1959 Fund for Excellence, for making this project possible. I also want to thank the members of my lab, my friends, and close family for motivating me. Although parts of this seemed like they would never end, I got through it.
References
Byrne, D. G., Davenport, S. C., & Mazanov, J. (2007). Profiles of adolescent stress: The development of the adolescent stress questionnaire (ASQ). Journal of Adolescence, 30(3), 393–416.
Kroenke, K., Strine, T. W., Spitzer, R. L., Williams, J. B., Berry, J. T., & Mokdad, A. H. (2009). The PHQ-8 as a measure of current depression in the general population. Journal of Affective Disorders, 114(1–3), 163–173.
Spitzer, R. L., Kroenke, K., Williams, J. B., & Löwe, B. (2006). A brief measure for assessing generalized anxiety disorder: the GAD-7. Archives of internal medicine, 166(10), 1092–1097.
Author and Mentor Bios
Originally from Claremont, ʤ, Amanda Wittemann is a neuroscience and behavior major, with psychology and women and gender studies minors, who will graduate from the University of ʤ (ʤ) in September 2027. Amanda completed the research described in this research brief with funding from a Summer Undergraduate Research Fellowship (SURF) from the Hamel Center for Undergraduate Research.
Jolie Wormwood is the Arthur K. Whitcomb Professor of psychology and started at ʤ in 2018. Dr. Wormwood’s research is broadly interested in affect and emotion, particularly how they influence our perceptions and decision-making, how we infer them in others, and the role of the body in their experience. Dr. Wormwood consistently mentors undergraduate students in the Affect and Social Psychophysiology (ASP) Lab, including several SURF recipients and past Inquiry authors.
Copyright 2025 © Amanda Wittemann
