Depression is the leading cause of disability worldwide, and antidepressant use has risen dramatically in recent years (1). Depression also happens to be one of several commonly reported side-effects of hormonal contraceptives, and mood symptoms are a known reason for stopping hormonal birth control treatment (2, 3).
I’ve written previously about depression as an inflammatory condition. In this article, I will specifically focus on the associations between hormonal birth control and depression.
The Natural Hormone Cycle
The hormones estrogen and progesterone fluctuate over the menstrual cycle in a predictable pattern that is repeated every month. Estrogen and progesterone levels begin very low at the beginning of the cycle (the follicular phase), signaling the pituitary gland to produce follicle-stimulating hormone (FSH). FSH begins the process of maturing about 15 to 20 follicles, the fluid filled sacs in the ovaries that each contain an egg. The follicle produces estrogen to prepare the body and uterus for pregnancy.
Approaching ovulation (about midway through the cycle), high estrogen levels trigger the release of luteinizing hormone (LH) from the pituitary gland, causing the release of a single egg from the follicle (the ovulatory phase). The ruptured follicle (corpus luteum) begins to secrete progesterone and estrogen to continue to prepare the uterus for pregnancy (the luteal phase). If the egg is not fertilized, estrogen and progesterone levels drop and menses begins as the uterine lining is shed along with the unfertilized egg.
Types of Hormonal Contraceptives and How They Work
The primary types of hormonal contraception (HC) include the combined pill, progestin-only pill, IUD, implant, injection, vaginal ring, and transdermal patch. Hormonal contraceptives contain either synthetic estrogen and progestin (combination) or progestin only. Most HCs work by providing the body with synthetic hormones, keeping progesterone (and estrogen) levels consistently high. In the case of oral contraceptives, there is a sharp spike in hormones each day of the cycle that falls before the next day. (This is why oral contraceptives have to be taken daily to prevent pregnancy.)
The high levels of synthetic estrogen and progesterone “fool” the body into thinking it’s pregnant, inhibiting the secretion of LH and FSH and thus effectively blocking follicular development and ovulation. Progestin-only contraceptives also inhibit sperm penetration through the cervix by decreasing the amount and increasing the viscosity of cervical mucus (4).
The takeaway here is that hormonal contraceptives suppress the natural hormone pattern that occurs over the course of the menstrual cycle. We’ll see in the next few sections how these hormones are associated with mood and depression.
Sex Hormones, Mood, and Depression
A review by Toffoletto and colleagues found evidence that steroid sex hormones have an influence on cortical and subcortical brain regions involved in emotional and cognitive processing (10). Changes in estrogen levels may trigger depressive episodes in women at risk for depression, and adding progesterone to hormone therapy has been shown to adversely affect mood in women (11). Progesterone metabolites can mimic the neurotransmitter GABA, the major inhibitory system in the central nervous system (12). External progestins also increase levels of monoamine oxidase, an enzyme that degrades serotonin. It may do this more potently than endogenous progesterone (13).
Furthermore, a double-blind, randomized controlled trial recently found that women given a goserelin (a stimulator of gonadotropin-releasing hormone) implant had significantly greater subclinical depressive symptoms than those receiving a placebo implant. Depressive symptoms were positively correlated with a decrease in estrogen (14).
The Association of Depression and Contraceptive Use
Several studies have now studied the association between low-dose HC use and risk for depression. Two studies found that teens taking progestin-only contraceptives tended to be more frequent antidepressant users (15, 16). Another study found that use of combined oral contraceptives among women who previously experienced adverse emotional effects resulted in deterioration of mood and changes in emotional brain reactivity (17). A 2014 case report describes two female patients who developed depressive symptoms after starting hormonal contraception use (18). On the other hand, one study found no association between mood and oral contraceptive use (19), while three studies suggested that HC use was actually associated with better mood (20, 21, 22).
This type of birth control doubles your risk of depression
The most robust study, however, was published just last month and provides strong evidence for an association between HC and depression (23). The researchers designed a prospective cohort study, where patients are followed forward in time and outcomes are observed. The entire female population of Denmark between ages 15 and 34 was studied, thanks to extensive national registry data. Of the more than 1 million women studied, 55.5 percent were current or recent users of hormonal contraception.
So what did they find? Compared to non-hormonal contraceptive users, the chance of needing your first antidepressant was:
- 1.2-fold higher if you used a combined oral contraceptive
- 1.3-fold higher if you used a progestin-only pill or transdermal patch
- 2.0-fold higher if you used a vaginal ring
- 2.1-fold higher if you used an implant
Use of all types of hormonal contraceptives was also positively associated with subsequent diagnosis of depression. These risks were even higher for adolescents and for those who had been using hormonal contraception for a longer period of time.
Alternatives to Hormonal Contraception
Evidently, hormonal contraception is not as harmless as it is often made out to be.
I also know that women use HC for a number of reasons, not just preventing pregnancy. Fortunately, there are natural alternatives to HC:
- For PMS symptoms or painful periods: this is likely a sign that your hormones are out of balance. Check out this blog article and podcast for tips on how to fix your menstrual cycle and rebalance hormones naturally.
- For contraceptive purposes: one of the most effective non-hormonal options is the Fertility Awareness Method (FAM). FAM is a natural method of preventing or achieving pregnancy by tracking and charting the body’s cued responses to hormone fluctuations over the menstrual cycle. Due to the combined maximum survival time of an unfertilized egg (1 day) and sperm (5 days), there is only a small portion of a woman’s cycle where she can actually get pregnant. This method uses basal body temperature, cervical fluid, and cervical position to effectively predict ovulation so that you can choose to avoid unprotected sex during the fertile time around ovulation.
While there has not been a ton of research in this area (it’s not anywhere near as profitable to study cycle charting as it is to study a birth control pill), a review of robust clinical trials found that the FAM symptothermal method for contraception has about 98 percent effectiveness for typical use and about 99.5 percent efficacy for correct use (24). In comparison: condoms are 98 percent effective when used properly, and birth control pills are between 91 and 99 percent effective. However, it should be noted that FAM does not protect against STDs.
For more information on FAM, I highly recommend the book Taking Charge of Your Fertility, by Toni Weschler.