Science & Tech

Birth control pill pack. Image: Unsplash/Stock
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How much is your birth control really affecting you? New research says that it’s more than you may think. U of O researcher Andra Smith has spent the past several years trying to understand the popular medication’s neurophysical and developmental effects on its users.

Smith, who in addition to being a researcher, is a full-time professor within the faculty of social science and psychology. She has researched throughout her career the neural impacts of cocaine, marijuana, psychiatric disorders, mindfulness, and most recently, the use of synthetic hormones in birth control. 

In 2020, Smith and co-authors Nafissa Ismail and PhD student Rupali Sharma from the University of Ottawa, published a study titled “Use of the birth control pill affects stress reactivity and brain structure and function.” The study sought to research the impacts of early oral contraceptive use on brain development, structure, and function in its users.

How does birth control work?

Birth control works by altering the levels of specific hormones (estrogen and progesterone) throughout the menstrual cycle. Typically, these levels vary over the course of a month and their general presence or absence dictates when ovulation and menstruation occurs. Although there are many types of oral contraceptives, the general guideline is that they are composed of synthetic versions of naturally occurring hormones, namely progestin instead of progesterone. 

A pill is taken every day, typically at the same time, to keep the hormone levels even throughout the cycle. The notable exception is for four-seven days at the end of the month, where there are either no pills or “sugar pills” that contain no hormones, which allow for a period to occur.

Is birth control supposed to affect the brain?

It’s a common misconception that birth control doesn’t affect the brain. However, this makes very little sense in actuality because the brain is responsible for hormone control, with the endocrine system — namely the hypothalamus and pituitary gland — starting there.

Smith clarified that “the hypothalamus, for example, controls the release of hormones and the production of some hormones. So, absolutely, oral contraceptives are going to impact the brain.”

Research objectives and proceedings

One of the main objectives of this study was to look at how brain development was affected based on differences in the age of the medication’s users. 

Researchers did this by comparing users who started using oral contraceptives within the first six months following their first period (pubertal onset) and those who started using after the age of 18. These participants were also compared to a control group that had never taken contraceptives. 

The birth control users underwent stress, anxiety and depression testing, memory tasks, an MRI session as well as basic questionnaires to determine eligibility and demographics. During the memory tasks, participants were asked to view negative, positive, and neutral images, with their memory of each being measured.

What did the researchers find?

One of the main findings of the study was that in general, those using oral contraceptives “had more activity in their prefrontal cortex during negative image processing and working memory,” said Smith.

This suggests that those groups had to work harder to remember the negative images. It is also important to note that the prefrontal cortex is part of the brain that is still in development in your teenage years, thus offering up an explanation as to why it was affected.

Also notable was a visible blunted stress response, meaning that those on oral contraceptives didn’t react as much to stressors as those not on contraceptives.

Additionally, there were differences in amounts of grey and white matter in the brain. The location of a distinct lack or addition of grey/white matter was also distinguishable based on whether the women had been taking oral contraceptives.

Of note, the duration that users had been taking birth control also played a role in impacting both brain structure (white and grey matter specifically) and function, for example in frontal brain activity. Thus, it is not simply the age of onset that plays a key role, but also for how long a person has been using the medication. 

Birth control and depression: is there a relationship?

In essence, yes. Although it is not fully understood why exactly, this research revealed that users who started taking oral contraceptives earlier had a blunted stress response. Smith clarified that although this may seem like a good thing, it’s not. The diminished stress response has actually “been correlated with things like depression.” This may not be desirable, given the existing increase in anxiety and depression throughout adolescence. This finding also supports users who have come forward with mental health concerns in the past after using an oral contraceptive.

Most surprising result

When asked what Smith found most surprising about the research, she responded that “the biggest thing was that, despite the fact that we had a small sample, we were still able to see significant differences between the [early] pubertal onset users and the adult users. That you could actually see that in the brain.” 

Final Takeaways 

Most importantly, the effects of birth control need to be discussed with a health care practitioner. Birth control, like every other medication, is a balance of pros and cons, and it should be up to each patient whether the personal benefits outweigh the risks. Oral contraceptives do have an impact on emotion, cognition, and brain development, all of which should be factored into the decision.