How Does Stress Affect the Body?

Stress has unfortunately become a commonplace aspect of many of our lives as we enter a second year of a global pandemic. In fact, a survey last fall reported 32% of adults felt so stressed by the pandemic that they sometimes struggle with daily tasks like choosing what to wear or eat, let alone work or go to school. It’s clear that stress can change the way we think, but how? Jenna Rieder, PhD, assistant professor in Psychology in Jefferson’s College of Humanities and Sciences, is interested in how stress and traumatic events change the physiology in not just our brains, but also our bodies. Her findings will help us better understand how our bodies respond to acute stress, and how those responses change in mental disorders like post-traumatic stress disorder. Read on to learn more about her research.

Q: Tell us a bit about your field or area of research.

A: My research is focused on stress—a topic that most people can probably relate to. I am interested in both normative stress (what most of us experience in daily life) and more extreme stress. A lot of my work has focused on how the stress system works, particularly in trauma-exposed or chronically stressed people. I am interested in learning more about how stress relates to differences in physiology, and how these mechanisms might underlie clinically relevant outcomes, such as risk for mental illness. This research is situated at the intersection of many different areas of psychology (e.g., behavioral neuroscience, health psychology, clinical psychology) and the projects I’ve worked on employed a variety of methods, including chemical analysis of hormones in saliva samples, which have the advantage of being non-invasive compared to blood samples. The procedure is also a lower burden emotionally and doesn’t induce stress, which could impact measurements. Alongside this bench science, I also conduct clinical interviews with participants. In other words, we study both a person’s perception of stress as well as probing how stress impacts and interacts with different components of our bodies.

Q: What are some of your recent projects?

A: My recent work has focused on the impact of estradiol on daily affective (emotional) experiences, including mood patterns and symptoms of posttraumatic stress disorder (PTSD), in trauma-exposed women. Estradiol is an ovarian hormone that interacts with stress hormones, like cortisol, in naturally-cycling women. Fluctuations in estradiol have been linked with changes in mood and cognition, and changes in function of our stress systems. Yet, most existing research on PTSD has not looked at whether fluctuations in this hormone might impact the daily experiences of women who have experienced traumatic events.

My colleagues, Olena Kleshchova and Mariann Weierich at the University of Nevada, Reno, and I recently published a paper that shows that among trauma-exposed women, daily affective experiences, including PTSD symptoms, differ by menstrual cycle phase. We tracked our participants’ experiences over the course of ten days, which spanned both low-estradiol and high-estradiol phases of the menstrual cycle. During the lower-estradiol portion of the cycle, our participants experienced more PTSD symptoms, as well as greater changes in mood. These results could help clinicians anticipate times of increased symptoms in their trauma-exposed clients who menstruate, and that information could also be imparted to their clients as a form of psychoeducation.

In a related project, we tested differences in the association between estradiol and symptoms by trauma type. We found that the relationship was strongest in women who had experienced sexual, chronic or early-life trauma. In other words, the kinds of events that often put people at greater risk for PTSD symptoms are also associated with greater sensitivity to changes in estradiol.

In addition, I'm also working on a study that tracked undergraduate students’ experiences during the pandemic, which in many ways, has been an unprecedented collective stressor. During the Spring 21 semester, my colleagues (Olena Kleshchova, Mariann Weierich, and Erick Fedorenko) and I collected longitudinal data, that is to say we surveyed our respondents across three campuses for information at multiple time-points during the semester, rather than just once. We used this survey to capture the range of experiences that undergraduates have had. We are analyzing this data now to better understand the factors that predict maladaptive adjustment to pandemic-related stressors. This work potentially has implications for policy and educational practices in the current situation, but also gives us an opportunity to study individual differences in responding to life-disrupting stressors.

Q: What’s the fire in your belly that drives your passion for your research?

A: Stress is something that many people view as purely psychological. I hope to contribute to our knowledge of how stress can tangibly affect physiology, health and well-being. I also think it’s incredibly important for us to understand how estradiol can impact mental health in women. Compared to men, women are twice as likely to develop PTSD following a traumatic event, yet historically, much of the research on PTSD has focused on men, and studies that included women have not always considered hormonal status or menstrual cycle phase.

Q: What’s a cool or little known or unique fact about your work?

A: A lot of researchers who collect saliva samples send them away for analysis, but in the lab where I was trained and did much of this work, we analyzed the samples ourselves. I think people are surprised sometimes that I’ve done this type of bench work, because it’s not what people typically picture psychologists doing.

Q: If you had any words of advice for an aspiring researcher or student in this field, what would they be?

A: Don’t be afraid to get experience in an area that is slightly tangential to your main interests. Any research experience will help you acquire skills that will generalize to different areas of study, and learning a variety of different methods can give you additional tools or strategies for approaching questions.