Sex Hormones & the Female Brain: A Focus on Mood Disorders

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Female sex hormones can have effects on the brain both during hormonal transition periods and across a woman’s lifespan, including short-term shifts during the menstrual cycle.1,2 A 2021 review, published in Neuroendocrinology, showed an overall reduction in grey matter and region-specific decreases in brain areas during puberty and the menstrual cycle, during pre- and post-pregnancy, as well as during perimenopause and menopause, where the decline in sex hormones was paralleled with a reduction in hippocampal and parietal cortex volume. These changes in brain volume were significantly correlated with estradiol, testosterone, progesterone, and luteinizing hormone levels in some of the studies included in the review, but directionality remains inconclusive between studies. The comprehensive results indicate that sex hormones play an important role in brain plasticity during female hormonal transition periods, and, most notably, are not restricted to developmental periods.2 Fluctuations in female hormones are highly expressed in brain areas important for emotional processing and may predispose women to mood disorders,2 as they interact with neurotransmitters such as serotonin, dopamine, GABA, and glutamate.3

Depression is disproportionately reported by women (almost twice as often as by men) during reproductive age.4 For example, the worldwide annual prevalence of depression in 2010 for females and males was 5.5 and 3.2%, respectively. In the US, women had an approximately two-fold higher risk of depression than men, with 21.3% of women and 12.9% of men experiencing major depressive episodes during their lifetimes. Some researchers speculate that a potential mechanism accounting for this difference, in part, may include covariation between estrogen levels and the incidence peak of female depression.4

Interestingly, this distinction between sexes is most prominent during the reproductive years.3 The overall heightened risk for depression in women can begin as early as puberty3 due to fluctuating estradiol levels.5 While some women may experience depression during pregnancy,3 researchers speculate that pregnancy may sometimes offer a form of protection against depression. The peripartum period is considered high risk for mood instability in women with a history of major depressive disorder (MDD) and bipolar disorder (BD).6,7 A 2021 review by Yu et al focused on triggering factors related to postpartum disorder (PPD), such as reproductive hormones, stress hormones, and inflammation, suggesting that progesterone levels, which progressively increase throughout pregnancy and drop rapidly after delivery, may be correlated with PPD. The authors also suggest that a low prenatal allopregnanolone (a progesterone derivative) may predict PPD.8

The severity of mood fluctuations throughout a woman’s lifespan ranges from reports of low mood, irritability, impulsivity, and fear to severe suicidal behavior.3 A subgroup of women suffer from clinical levels of premenstrual mood changes called premenstrual dysphoric disorder (PMDD), which includes symptoms like anxiety, irritability, and depressed mood.3 Premenstrual exacerbations (PME) of ongoing mood disorders are well studied; a 2021 review estimates that in women with mood disorders, approximately 60% report PME, while some women with bipolar disorder also show symptom exacerbations around ovulation.2 During perimenopause, women enter a vulnerable period for developing a depressive illness, with women who begin the menopausal transition early having a more significant risk of first onset depression.3

While there is evidence of the beneficial effect of hormone therapy on cognitive and affective function,9 hormone replacement therapy (HRT) can elicit significant side effects and is not the only treatment option. While HRT is an extremely common intervention, it has its own health risks and may not address the underlying causes of hormonal imbalance. The functional medicine approach is to look upstream at the wide variety of ways that the hypothalamic, pituitary, adrenal, thyroid, and gonadal (HPATG) axis modulates health. By applying dietary modifications, nutraceutical supplementation, and other lifestyle changes as a frontline treatment, the need for HRT can often be minimized or avoided.

Functional Medicine Clinical Considerations for Balancing Hormones

Nutritional Interventions

Research suggests that specific nutrients, dietary patterns, and overall nutrition may play either beneficial or detrimental roles in hormonal balance. Understanding potential nutrition-hormone relationships, including hormone signaling sensitivity, is a key part of the functional medicine approach to hormonal dysfunction. At the most basic level, consumption of anti-inflammatory foods—specifically fruits and vegetables—may help alleviate symptoms of many chronic conditions associated with increased inflammation.10-13

Determining the underlying cause of a hormonal imbalance or dysfunction may be challenging, depending on the individual patient and presentation. Understanding a cell’s sensitivity to hormonal signaling and what may be influencing any impaired signal reception is an important consideration for a subsequent intervention. Cellular sensitivity is the S in IFM’s “PTSD” mnemonic, which is used in the general assessment of hormone dysfunction and helps determine if the dysfunction is related to hormone production, hormone transport, signaling sensitivity, or to an issue with detoxification. This functional medicine approach also helps identify points of leverage where physicians can apply individualized interventions to help restore hormonal balance.

Two enzymes, aromatase and 5-alpha reductase, may affect the conversion of testosterone to estrogen and the conversion of testosterone to dihydrotestosterone, respectively. Modulating these enzymes can therefore have a significant impact on the levels of testosterone and estrogens circulating in the body. A variety of factors affect those enzymes, and IFM has created patient handouts that list foods, herbs, and nutrients that have been shown to modulate these hormone levels. In the IFM Clinical Practice Toolkit, these are titled “Maintaining Healthy Testosterone Levels” and “Aromatase Inhibitors.”

Exercise Interventions

High estradiol is associated with mood dysfunction in women, and exercise can address this imbalance.14 A 2015 systematic review and meta-analysis based on randomized controlled trials conducted among healthy women demonstrates a significant decrease in total and free circulating estradiol concentrations induced by physical activity. This finding confirms the associations reported in observational studies, independent of menopausal status. The study concludes that overall, physical activity induces a decrease in circulating sex hormones.14

Hormone homeostasis and levels of physical activity are also factors known to modulate hippocampal plasticity and lead to strengthening (long-term potentiation) or weakening (long-term depression) of synapses.15 Physical activity is a potent modulator of HPG activity and circulating sex hormone concentrations. A 2020 study on the interplay between hormones on hippocampal plasticity across the lifespan suggests that:

  • Exercise modulates systemic and local levels of stress hormones, sex hormones, and metabolic hormones.
  • Exercise-induced hormonal changes modulate hippocampal neuroplasticity.
  • Exercise benefits hormonal balance and neuroplasticity throughout the lifespan.15

Learn how to re-establish hormonal balance in IFM’s Hormone Advanced Practice Module (APM). This functional medicine Advanced Practice Module will clarify exactly how to approach hormonal dysregulation, with discussions on the most important evaluations to make and integrative treatment approaches to apply. IFM’s faculty team supplies clinicians with the foundational background, insight, and in-depth clinical thinking to confidently assess and treat patients who present with hormonal dysfunction. Learn more:

LEARN MORE ABOUT RE-ESTABLISHING HORMONAL BALANCE>

Related Articles

Chronic Stress and Hormone Disruption 

Reducing Chronic Disease Risk at Menopause Using Nutrition 

Women’s Health: Supporting Ovary Function and Longevity 

References

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  2. Kuehner C, Nayman S. Premenstrual exacerbations of mood disorders: findings and knowledge gaps. Curr Psychiatry Rep. 2021;23(11):78. doi:1007/s11920-021-01286-0
  3. Barth C, Villringer A, Sacher J. Sex hormones affect neurotransmitters and shape the adult female brain during hormonal transition periods. Front Neurosci. 2015;9:37. doi:3389/fnins.2015.00037
  4. Shi P, Yang A, Zhao Q, Chen Z, Ren X, Dai Q. A hypothesis of gender differences in self-reporting symptoms of depression: implications to solve under-diagnosis and under-treatment of depression in males. Front Psychiatry. 2021;12:589687. doi:3389/fpsyt.2021.589687
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  11.  Zwickey H, Horgan A, Hanes D, et al. Effect of the anti-inflammatory diet in people with diabetes and pre-diabetes: a randomized controlled feeding study. J Restor Med. 2019;8(1):e20190107. doi:14200/jrm.2019.0107
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  13.  How to use food to help your body fight inflammation. Mayo Clinic. Published August 13, 2019. Accessed March 21, 2022. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/how-to-use-food-to-help-your-body-fight-inflammation/art-20457586
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  15.  Bettio LEB, Thacker JS, Rodgers SP, Brocardo PS, Christie BR, Gil-Mohapel J. Interplay between hormones and exercise on hippocampal plasticity across the lifespan. Biochim Biophys Acta Mol Basis Dis. 2020;1866(8):165821. doi:1016/j.bbadis.2020.165821