TLDR: A Danish study found that women using hormonal birth control were more likely to experience depression compared to women not using hormonal birth control. What many headlines didn’t mention was that the risk of depression in both groups was quite low (around 2%), and that several factors make it tricky to interpret this study's results. The takeaway is simple: If you feel good on your method, don't let the headlines scare you. If your method isn’t working for you, don't settle—find a different one.
In a new study that included over a million women in Denmark, researchers looked at whether there's a link between depression and using more than a dozen kinds of birth control with hormones. They followed women ages 15-34 from 2000 through 2013, using information about the women's prescriptions to compare those who were using hormonal birth control with those who weren't. The researchers looked at depression in two ways:
- getting a first prescription for an antidepressant, and
- being diagnosed by a medical professional with depression.
The researchers also took into account other things that could be associated with depression, like age, education, and diagnoses of polycystic ovarian syndrome (PCOS) or endometriosis.
Some scary numbers
The study found that, overall, women using hormonal methods were about 20% more likely to fill a prescription for an antidepressant and about 10% more likely to get a diagnosis of depression when compared to women who didn't use hormonal birth control. Because there were so many women in the study, the researchers were able to look at specific types of hormonal birth control. They found that not all birth control methods were created equal when it came to the link with depression. Specifically, compared to women not using hormonal birth control:
- Women using low-dose pills with the progestin norethisterone were no more likely to use antidepressants or have a diagnosis of depression. (Examples are Loestrin, Microgestin, Junel, Ovcon 35, Zenchent, Zeosa, Femcon, Balziva.)
- Women using any pills with norethisterone, including progestin-only pills, were no more likely to have a diagnosis of depression.
- Women using pills with the progestin drospirenone (Yasmin, Ocella, Yaz, Gianvi); high-dose pills with 50 micrograms of estrogen (Ortho Novum, Necon, Norinyl, Ovcon 50, Ovral, Ogestrel); and a pill with estradiol valerate and dienogest (Natazia) were 40-80% more likely to use antidepressants. Most of the same pills were associated with a similar increased risk for a diagnosis of depression.
- Women using the patch were 100% more likely to use antidepressants and 70% more likely to be diagnosed with depression.
- Women using the ring had a 60% higher risk of both outcomes.
- Women using the hormonal IUD had a 40% higher risk for both outcomes.
- We don't have data on depression diagnoses for women using the shot or the implant, but shot users were 170% more likely to use antidepressants and implant users were 110% more likely.
- Women under age 20 using any hormonal method seemed to be particularly susceptible to depression, with about an 80% increase in the use of antidepressants and diagnoses of depression.
Some context for the scary numbers
This is another case of scary headlines about birth control not telling the whole story. It's important to know that these numbers tell you the change in the risk, not the risk itself. If we look at the risk itself, the findings seem less dramatic. In other words, while the study found a difference in the chances of depression between hormonal birth control users and everyone else, the number of women dealing with depression was quite low in both groups. Specifically:
- Women not using birth control with hormones started taking antidepressants at a rate of 1.7 per 100 women each year. That's just under 2% of women each year.
- In comparison, women using birth control with hormones started using antidepressants at a rate of 2.2 per 100 women each year. That's just over 2% of women each year, or a difference of 0.5%.
- There was an even smaller difference in the rate of women diagnosed with depression by their birth control use. Those using birth control with hormones got depression diagnoses at a rate of 0.3 per 100 women each year. Those not using these methods were diagnosed at a rate of 0.28 per 100 women each year. That's about 1 in 300 women each year in both groups.
We're grateful to the Danes for doing this kind of research, especially because it would be impossible to do in the United States. We're also grateful because it's a step in the right direction in trying to understand this very complicated topic.
Here are just a couple of the reasons why studying birth control and depression is so complicated:
- If you start using birth control and you feel crappy, it's common to switch to a different method. So you switch from being, say, a pill user to being a copper IUD user right around the time that you experience what the researchers are looking for. I.e. folks who stop using a method due to depression may not be counted as users of that method.
- There are things that could be related to both depression and birth control that no study has ever been able to take into account, like being in your first serious relationship, not getting enough sleep due to your baby or toddler, and negotiating sex with partners.
Researchers just don't have access to this kind of information in medical records—even in Denmark!
Can’t we do better?
One way to address these complications would be to compare apples to apples. We know from other studies that women using birth control are different in some basic ways from women not using birth control at all. For example, many women not using birth control are actively trying to get pregnant or not having sex, either of which could be related to the chances of depression. For this reason, it would be better to compare women using any birth control method with hormones to women using any method without hormones, leaving out the women who aren’t using birth control at all.
Still, the only way to get an iron-clad answer about the link between hormonal birth control and depression would be to randomly have some women use birth control with hormones and some use a placebo, and make sure neither the women nor their doctors knew which type of pill they were taking (aka, a double-blind placebo controlled trial). Obviously it's not okay to do this type of study if women are relying on birth control to avoid pregnancy. Three small studies have been able to get around this because their participants either already had birth control (sterilization) or were using the pill for reasons besides pregnancy prevention, like painful periods or acne. Although these studies are small and some are quite old, it's worth mentioning that two of them showed no association between the pill and depression or mood changes, and one showed that progestin-only pills might protect against depression.
Sooo... should we be worried?
This study confirms what many birth control users already know: different methods can affect people very differently. You know your body best. If you feel good on your method, you don't need to worry about this study. If you don't like how your birth control method makes you feel, don't settle. Talk to your health care provider about switching it up until you find a method that works for you.