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The Physiology of Stress - How Does The Endocrine System Affect Your Mental Health?

By Elizabeth James

We have all experienced it at one point —you can’t sleep, you’re anxious, and you feel overwhelmed by every task required of you. Physically, you feel that your body is distressed, and you can tell you are not in a good mental state. We can be negatively impacted by stress, but we might not be aware of the biological effects of stress on our bodies (APA). What causes these physical and emotional stressors? A combination of factors come into play to produce these responses, but one of the main underlying factors happens to be hormone response. The primary hormone involved in this response is cortisol, a steroid made from cholesterol (Thau et al. 2020). You may be wondering what controls this hormonal response —the endocrine system.  

The main hormonal response is produced by the hypothalamic-pituitary-adrenal (HPA) axis. The hypothalamus, located in the brain, is a pea-sized collection of nuclei that connects the brain and endocrine system (APA). The hypothalamus is the main decision maker of the endocrine system, and it initiates all hormonal responses (APA). When you experience a stressful event, such as an important exam or a breakup, the hypothalamus sends a signal to the pituitary gland by releasing corticotropin-releasing hormone (Johns Hopkins). The pituitary gland then produces adrenocorticotropin hormone, which continues the signaling cascade by telling your adrenal gland to produce increased levels of cortisol. Cortisol is a primary messenger, and it enters the cell by passing through the cell membrane (Thau et al. 2020). Once inside the cell, cortisol binds to a glucocorticoid receptor and triggers a cellular response (Thau et al. 2020). Cortisol increases gluconeogenesis, which is the process of producing glucose from pyruvate molecules to use it for energy production (Thau et al 2020). This action increases the level of ATP, or adenosine triphosphate, which is the energy source your body uses to react to stressful situations (Thau et al. 2020). Cortisol also narrows the arteries, which leads to increased blood pressure and heart rate, and also leads to feelings of anxiety (APA). Your body typically produces cortisol throughout the day at varying levels, and it is needed for normal biological functioning (APA).  

Cortisol is also involved in immune system regulation. The issue with prolonged stress is that this signaling cascade will be used more than normal, which may desensitize the response downstream of the HPA axis and prevent it from communicating with your immune system normally (APA). This may not seem to be a big deal at first, but decreased communication between the HPA axis and your immune system can lead to a myriad of potential mental and physical illnesses. These illnesses include depression, as well as diabetes and immune disorders. In fact, hyperactivity of the HPA axis is one of the most common factors underlying the development of depression (Yang et al. 2015).  

 Many aspects of college can put an unhealthy amount of stress on students, especially if you are a high achiever or need good grades to get into medical school or other graduate level programs. Grades are important, but they should not lead to the development of serious diseases such as the depression and diabetes. Stress can impact everyone differently so coping mechanisms can differ person to person. A few things that seem to work for college students include exercise and decreasing caffeine consumption (Lovello et al. 2005). Those may seem like impossible goals, but even 10 minutes of exercise a day can significantly decrease stress and increase endorphin production. This could be as simple as stretching when you wake up or going on a walk down a South Oakland street (with your mask on, of course). According to APA, exercise alone can decrease stress by 62%. Decreasing caffeine consumption may seem like an unattainable goal especially if you have an 8:00am class, or gold status at Starbucks, but it is possible. Sticking to one cup of coffee a day or reducing caffeine intake in the afternoon are easy ways you can cut back. 

The endocrine system is important for your physical and emotional wellbeing, and your endocrine system will be more likely to function normally if you are taking care of your mental health. If you are feeling unreasonably stressed, do not be afraid to reach out for help—Pitt has a counseling service that is HPA axis approved. Your hypothalamus—and your future self—will thank you.