Landmark Study Links Hormonal Birth Control And Depression

Teens who used the patch or the IUD were the most at risk.

29/09/2016 1:40 AM AEST | Updated 29/09/2016 1:40 AM AEST
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If you’ve been feeling a little bit “off” since you started a new hormonal birth control, don’t dismiss that observation.

New long-term research on more than a million women in Denmark found that some hormonal contraceptives are linked to a small but clear increased risk of depression. What’s more, this association between heightened depression risk and birth control use was especially strong in adolescents.

The study adds robust evidence to a research topic that, until now, resulted in mixed findings. While some previous research suggested a link, one study suggested that hormonal contraceptives result in no change in mood for women, and other studies found that hormonal birth control actually improves mood for some.  

While most women won’t experience clinical depression or need antidepressant medication soon after starting birth control, experts say the results suggest that doctors who prescribe birth control to first-time users should be on the lookout for potential changes in mood in the first few months.

It’s also a reminder that women starting on any kind of hormonal medicine, or indeed any medicine at all, should be careful to note any changes ― good or bad, physical or mental ― and discuss them with a doctor.

Different birth control methods had different risks of depression 

From 2000 to 2013, researchers at the University of Copenhagen tracked data on more than one million Danish women and teens between the ages 15 to 34. 

They used the Danish equivalent of a social security number to track prescriptions and diagnoses, using a national prescription database and national psychiatric registry. This allowed them to see who received and filled prescriptions for hormonal birth control and who went on to be prescribed antidepressants or receive a diagnosis of depression.

They found that 55 percent of the women and teens were either current or recent users of hormonal contraception including birth control pills, the patch, the vaginal ring, or hormonal IUDs. Among these women, the researchers found that antidepressant use and depression diagnosis risk varied according to both age and method of contraception, compared with non-users.

Compared to women who didn’t use hormonal birth control…

Women who used the combined birth control pill, a mix of estrogen and progestin, had a 1.23 times higher relative risk of being prescribed antidepressants for the first time, while those on progestin-only pills had a 1.34 times higher relative risk.

Hormonal contraception from devices seemed to lead to a higher risk than pills: Women who used the patch had a two-fold higher relative risk, while those who used the vaginal ring had a 1.6 times higher relative risk and women with a hormonal IUD had 1.4 times higher relative risk.

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When broken down by age, teens aged 15 to 19 had an even higher risk of antidepressant prescription: Those using the combined birth control pill had a 1.8 higher relative risk, while those using progestin-only pills had a more than two-fold higher relative risk. Finally, teens who used non-oral forms of hormonal contraception had about a three-fold higher risk for first use of an antidepressant.

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As for depression diagnoses, the researchers found similar or slightly lower estimates than antidepressant prescriptions for everyone. 

The researchers excluded from their analysis all women who had been diagnosed with depression or used antidepressants before their 15th birthday or before the study started, as well as women who had other major psychiatric diagnoses. Women with cancer, venous thrombosis or those who underwent treatments for infertility before the study were also excluded, as the conditions preclude them from using hormonal birth control. Women who got pregnant were temporarily removed from the analysis during pregnancy until six months after birth to account for the potential effect of postpartum depression. 

Teen heartbreak and other alternative explanations

The findings raise questions about the hormones’ potential effects on women, and especially developing teen brains, says Dr. Anna Glezer, a reproductive psychiatrist at the University of California, San Francisco and founder of the educational site Mind Body Pregnancy

The research does not definitively establish that hormonal medication causes depression. But a connection of some kind may be likely, given the large number of women studied, the objective measures (like actual data for the fulfillment of prescriptions, as opposed to relying on patient recall) and the various analyses they used to make the data more accurate.

The Danish researchers theorize that progestin, the synthetic version of progesterone used in many of the contraceptives, may play a role in the development of depression, but they don’t yet know how or why.

But one alternative theory could be that first use of contraception probably coincides with a first serious relationship, putting teens especially at risk for broken hearts and depression, according to Catherine Monk, an associate professor in psychiatry, obstetrics and gynecology at Columbia University Medical Center. 

“The possibility that this link between love, sex (contraception), and feeling depressed is strengthened by the fact that the contraception-depression link was strongest in adolescents, those who are at the developmental stage where trying to find a romantic partner is paramount,” said Monk, who, like Glezer, wasn’t involved in the research but did review its findings.

The researchers themselves don’t put much stock in this interpretation, as most teens in Denmark use condoms rather than hormonal birth control for their first sexual experiences.

It’s also important to note that hormonal contraception is often prescribed to treat mood problems linked to the menstrual cycle, like premenstrual dysphoric disorder, said Monk. This could mean that both the birth control and antidepressants were prescribed to a woman to treat a pre-existing, underlying problem. But there are problems with this theory, too. 

“Their data showing that first came the hormone medication, then came the signs of depression evidenced in psychiatric medication prescriptions and/or psychiatric hospitalization, works against that [theory],” Monk pointed out.

So, should you take hormonal birth control? 

While the figures may seem alarming, it’s important to note that the rates of developing depression or using antidepressants were very small overall. Only a tiny minority of women went on to take antidepressants or be diagnosed with depression, whether they took birth control or not. 

Still, the findings do offer a word of caution to young teens and first-time users of hormonal contraceptives. All women considering hormonal medications should approach them thoughtfully, and with a strong sense of self, Monk said.

“For some women, this form of birth control works really well, but for others, it may not,” she said. “This study suggests it is possible hormonal contraception can be associated with risk for depression, so one needs to consider the risk.”

For doctors, this means having a longer discussion with women about the potential side effects of the medication, which may include changes in mood that are both positive and negative, says Glezer.

Doctors should also be prepared to follow up a new birth control prescription with another appointment sooner than they normally would ― especially for younger women and first-time users ― to see how the medication is affecting them, and if any changes are needed.

“If it were a mild [mood] change in the negative direction, I’d talk about potential ways to treat that change — maybe a brief course of supportive psychotherapy, exercise, or other lifestyle changes that would help with mood,” Glezer said. “If it doesn’t improve after three to six months, then it might mean that she needs a change in formulation of the hormones or an alternate form of contraception.”

Glezer also pointed out that hormonal birth control helps women avoid unplanned pregnancy, which itself is linked to a host of other risks, including a heightened risk of postpartum depression

Women shouldn’t dismiss their own observations about changes in mood and behavior as “it’s all in your head,” Monk concluded.

“We are in the era of personalized medicine ― the right treatment, at the right time, for the right patient,” she said. “It is not one size fits all in health care.”

The research was published in the journal JAMA Psychiatry

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