There is limited research on how hormonal birth control may affect the adolescent brain. Some studies have suggested that hormonal contraceptives may have an impact on brain structure and function, but more research is needed to understand the full range of potential effects.
One study published in the Journal of Clinical Endocrinology and Metabolism found that hormonal contraceptive use was associated with changes in brain structure and function in women. However, it’s important to note that this study did not specifically examine the effects of hormonal contraceptives on the adolescent brain.
One aspect of hormonal contraception’s effect on the adolescent body remains unknown: whether and how they alter the developing brain. Synthetic hormones found in birth control pills, patches, and injections have been linked to disrupted signal transmission between cells in the prefrontal cortex, an area of the brain that continues to develop throughout adolescence, according to new research in young rats.
Hormonal contraceptives are considered good choices for adolescents because they are safe and highly effective at preventing pregnancy, but one aspect of their effect on the adolescent body remains unknown – whether and how they modify the developing brain.
Synthetic hormones found in birth control pills, patches, and injections have been linked to disrupted signal transmission between cells in the prefrontal cortex, an area of the brain that continues to develop throughout adolescence, according to new research in young rats. The animals receiving hormonal contraception produced higher levels of the stress hormone corticosterone, which is similar to cortisol in humans when compared to control rats.
The researchers at Ohio State University began this line of research in the prefrontal cortex, a region where the mood is regulated because previous research has linked early adolescent use of hormonal contraceptives to an increased risk of depression in adulthood. But what’s most important, the researchers said, is learning how birth control affects the developing brain so individuals can weigh the risks and benefits of their reproductive health choices.
Birth control has had a significant positive impact on women’s health and autonomy, so we’re not suggesting that adolescents avoid hormonal contraception.Benedetta Leuner
“Birth control has had a significant positive impact on women’s health and autonomy, so we’re not suggesting that adolescents avoid hormonal contraception,” said senior study author Benedetta Leuner, an associate professor of psychology at Ohio State.
“What we need is to know what synthetic hormones are doing in the brain so that we can make informed decisions, and if there are any risks, they must be monitored. If you decide to use hormonal birth control, you will be more aware of warning signs if you are aware of any potential mood-related side effects.”
The research poster was presented at Neuroscience 2022, the annual meeting of the Society for Neuroscience.
An estimated 2 in 5 teenage girls in the United States have sexual intercourse between age 15 and 19, and the vast majority use a contraceptive – condoms in particular. Of those using birth control, almost 5% use hormonal contraceptives, also known as long-acting reversible contraceptives. These products are also prescribed to treat acne and heavy periods.
Despite their popularity, “there isn’t a lot known about how hormonal birth control influences the teen brain and behavior,” said co-author Kathryn Lenz, associate professor of psychology at Ohio State. “Adolescence is a crucially under-investigated period of dramatic brain change and dramatic hormonal change that we really haven’t understood.”
Female rats were given a combination of synthetic estrogen and progesterone commonly found in hormonal contraceptives for three weeks beginning about a month after birth, an age equivalent to early adolescence in humans. Researchers confirmed that the drugs disrupted the animals’ reproductive cycles; these birth control products work by preventing ovaries from producing hormones at levels required to generate eggs and making the uterine lining inhospitable for an egg to implant.
Blood samples revealed that treated rats produced more corticosterone than untreated animals, indicating that they were stressed. After being subjected to and recovering from an experimental stressor, the treated rats’ corticosterone levels remained high. Their adrenal glands were also larger, suggesting their stress hormone production was consistently higher than that of control animals.
An analysis of gene activation markers in the animals’ prefrontal cortex revealed a decrease in excitatory synapses in that region of treated rats’ brains compared to controls, but no change in inhibitory synapses – a phenomenon that could set up an imbalance of normal signaling patterns and result in altered behavior. Previous studies have linked the loss of only excitatory synapses in the prefrontal cortex to chronic stress and depression.
“We don’t know what this means for the operation of specific circuits. However, this hints at where we should look next in terms of what the functional outcomes might be” said Lenz.
The researchers are moving forward with additional studies focusing on hormonal contraceptive effects on the brain between puberty and late adolescence – a difficult time to study the developing brain because it is constantly changing, according to Leuner. The reasons for the drugs’ effects are also unknown.
“These are synthetic hormones, so are they affecting the brain because of their synthetic properties, or are they affecting the brain because they’re blocking naturally produced hormones?” she asked. “It’s a difficult question to answer, but it’s an important one.”