Shedding Light on SAD: Rebecca Gowen ’19 Researches Seasonal Affective Disorder

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During the summer, Colgate students are applying their liberal arts know-how in a variety of real-world settings, and they are keeping our community posted on their progress. Microbiology major Rebecca Gowen ’19, from Philadelphia, Pa., describes her summer research, conducted through the Beckman Scholars Program.

This summer, I am completing research as a Beckman Scholar with Associate Professor of Biology Krista Ingram. The Beckman Scholars Program allows me to conduct an independent research project directly relating to my interests in public health and molecular biology for 15 months.

Seasonal affective disorder (SAD) is a common subtype of depression that occurs in the winter as a result of short days with limited light exposure. I am studying chronic levels of cortisol — a steroid hormone — as a biological marker of SAD in two high-risk, genetically diverse populations in upstate New York: a Karen population that relocated from Myanmar to Utica and a local population in Hamilton, primarily of Caucasian-European descent. Individuals from equatorial regions who relocate to areas with long, harsh winters may be disproportionately affected by SAD as they may have not adapted to lower levels of sunlight.

We are using a longitudinal design, which entails repeated observations of the same variables. With this study design, we measure SAD, depression, and chronotype. Chronotype refers to circadian rhythms — when people are most alert and when they prefer to sleep in a 24-hour period.

We have hypothesized that participants with SAD experiencing depressive symptoms in the winter will have higher chronic cortisol levels at that time of year as compared to the summer, when SAD tends to subside. Other studies have found that individuals classified as evening types are more likely to be depressed, so we have hypothesized that evening chronotypes may also be more likely to have SAD.

The results of my research offer insight into how depression and chronotype influence the susceptibility of SAD. This can help develop prevention efforts and create more effective treatments, improving the lives of those affected.

I recently returned to Utica for a second sampling of the refugees. At the end of the study, each participant received a light bulb to mitigate SAD symptoms, along with educational materials about SAD.

As part of the Beckman Scholars Program, I will have the opportunity to present my research with Professor Ingram at a chronobiology conference in Barcelona, Spain, later this summer. I hope to apply the public health knowledge I’ve gained from this experience, when I begin my new job in San Francisco at a company that focuses on diabetes research and patient advocacy.