With its advent in the 1960s, the hormonal birth control pill was a revolutionary invention that allowed women to have greater control over their reproductive choices. With the freedom to decide when to start a family, more women than ever began to pursue educational and career endeavors outside of the home. In 1965, 26.2 million women participated in the U.S. labor force, and in 2014, that number soared to 73 million (Planned Parenthood, 2015).
Despite its effectiveness in preventing pregnancy, hormonal birth control can be accompanied by uncomfortable effects, such as nausea, headaches, bleeding in between periods, weight gain, and decreased libido (Brown University). There’s one less talked about yet, just as serious side effect: mood changes. About 4-10% of women report adverse mood effects that are so debilitating that they will discontinue use before finishing their first pill pack (Gingnell et al., 2013). These emotional changes may present as depressive symptoms, anxiety, irritability, and mood swings.
Research on the psychological effects of oral contraceptives is fairly limited but growing. In one study, 14 years’ worth of data from over 1 million women in Denmark revealed that women who used hormonal contraception were 50% more likely to be diagnosed with depression than their non-pill-taking counterparts just 6 months after beginning pill use.
To uncover why mood can be affected by the hormonal birth control pill, we have to get down to the biological level. The pill has been found to interfere with the body’s natural response to stress via a pathway called the HPA axis, or hypothalamic-pituitary-adrenal axis (Hertel et al., 2017). The HPA is a series of interactions between the brain and the body, specifically in the areas of the hypothalamus, pituitary gland, and adrenal glands. The hypothalamus and pituitary gland are located just above the brainstem and the adrenal glands are on top of the kidneys. When faced with a stress-inducing event, such as an upcoming exam or an interview, the HPA axis releases cortisol into the bloodstream. In order to cope with a stressor, cortisol creates physiological changes like increased heart rate to provide more blood to the muscles, and increased levels of glucose to the bloodstream to give you the energy to fight or flee. However, having too much cortisol from an overactive HPA axis has been linked to negative effects such as mood disorders, suppressed immune system function, type 2 diabetes, obesity, and cardiovascular disease. In addition, it has been found that life trauma and significantly stressful events can lead to a permanently overactive HPA-axis later in life (Dingman, 2014). Women on birth control have been found to have higher than normal free-floating cortisol in the body, which has been correlated with greater instances of anxiety and depression (Hertel et al., 2017). It is quite alarming that a pill could have psychological effects that are comparable to experiencing life trauma. The HPA axis is a crucial part of our body’s tool kit for fighting stress, but birth control pills can possibly deplete those resources for many women.
Throughout the menstrual cycle, sex hormones like estrogen and progesterone rise and fall in a predictable pattern. These fluctuations in hormones interact with the levels of brain chemicals, called neurotransmitters, in the brain. Neurotransmitters, like dopamine and serotonin, are involved in the emotion center of our brain. Our brain produces these chemicals when we engage in positive and rewarding activities such as talking to a loved one, eating a favorite food, or even having sex. Estrogen levels can affect how rewarding we find our favorite activities to be. Greater amounts of estrogen in the system are correlated with happier moods and increased pleasure from the things we love to do. Greater progesterone, however, has the opposite effect, reducing how rewarding these activities feel to us. The birth control pill works by keeping estrogen levels low throughout the menstrual cycle and stimulating progesterone receptors. The pill’s effect on the body’s natural hormonal cycle can make a huge difference in a woman’s day-to-day life. Decreased estrogen throughout the cycle can actually make the world feel far less rewarding, mimicking symptoms of depression: People with depression often report a loss of interest in activities they used to find pleasurable. Research has also shown that women on the pill are more likely to show a reduced positive emotional response to rewarding or positive images. When shown pictures of their romantic partners, they do not experience activity in the reward centers of their brains. As women often go on the pill to prevent pregnancy in committed relationships, it’s possible that the mood changes can put a damper on the emotionally rewarding aspects of the relationship. Women are thus faced with a dilemma: should they sacrifice their happiness over reproductive health?
It’s important to continue investigating the link between hormonal birth control and women’s mental well-being. The pill is 99% effective at preventing pregnancy, which makes it worth tweaking in order to be accessible to more women. One study shows that almost half of women who start the pill will discontinue it in the first year due to intolerable side effects (Sanders et al., 2001). Otherwise, the women who are left behind may turn to less effective forms of birth control, placing them at a higher risk for unwanted pregnancy.
Brown University. (n.d.). What are the side effects of birth control pills? www.brown.edu. https://www.brown.edu/campus-life/health/services/promotion/content/what-are-side-effects-birth-control-pills
Dingman, M. (2014, June 4). Know your brain: HPA axis. Neuroscientifically Challenged. https://neuroscientificallychallenged.com/posts/what-is-the-hpa-axis
Grabowska, K. (2020). Pink Pills on Yellow Surface [Photograph]. Pexels. https://www.pexels.com/photo/pink-pills-on-yellow-surface-4047112/
Hertel, J., König, J., Homuth, G., Van der Auwera, S., Wittfeld, K., Pietzner, M., Kacprowski, T., Pfeiffer, L., Kretschmer, A., Waldenberger, M., Kastenmüller, G., Artati, A., Suhre, K., Adamski, J., Langner, S., Völker, U., Völzke, H., Nauck, M., Friedrich, N., & Grabe, H. J. (2017). Evidence for Stress-like Alterations in the HPA-Axis in Women Taking Oral Contraceptives. Scientific Reports, 7(1). https://doi.org/10.1038/s41598-017-13927-7
Hill, S. (2020, March 26). Feel like a different person on the pill? Here’s how it affects your mood. Ideas.ted.com. https://ideas.ted.com/how-the-birth-control-pill-affects-your-mood/#:~:text=Mood%2Drelated%20issues%20like%20anxiety
Jarva, J. A., & Oinonen, K. A. (2007). Do oral contraceptives act as mood stabilizers? Evidence of positive affect stabilization. Archives of Women’s Mental Health, 10(5), 225–234. https://doi.org/10.1007/s00737-007-0197-5
Planned Parenthood Federation of America. (2015). The Birth Control Pill: A History [Fact sheet]. https://www.plannedparenthood.org/files/1514/3518/7100/Pill_History_FactSheet.pdf
Sanders, S. A., Graham, C. A., Bass, J. L., & Bancroft, J. (2001). A prospective study of the effects of oral contraceptives on sexuality and well-being and their relationship to discontinuation. Contraception, 64(1), 51–58. https://doi.org/10.1016/s0010-7824(01)00218-9
Skovlund, C. W., Mørch, L. S., Kessing, L. V., & Lidegaard, Ø. (2016). Association of Hormonal Contraception With Depression. JAMA Psychiatry, 73(11), 1154. https://doi.org/10.1001/jamapsychiatry.2016.2387