Teenage girls who take the birth control pill may be more likely to develop depression as adults, new research from University of British Colombia suggests.
The study, published last week in the Journal of Child Psychology and Psychiatry, surveyed 1,236 American women about their use of oral contraception and their history of major depressive disorders. It found that women who started taking the pill as teens were between 1.7 and three times more likely to develop clinical depression later in life, compared to both women who had either started taking the pill as adults and women who had never taken it.
“We can’t say for sure [that] pill use causes depression,” the study’s main author Christine Anderl explained to HuffPost Canada. “But we really did try to control for every single variable in the data set that we thought might provide an alternative explanation, and it never changed anything about the effect. If anything, sometimes the relationship became a bit stronger.”
How the pill works
Most oral contraceptives work by releasing estrogen and progesterone. Those synthetic hormones interact with the body’s natural estrogen and progesterone, keeping the body’s hormone levels consistent, so that eggs can’t mature and the uterine lining can’t develop in a way that will allow a fertilized egg to implant. The pill also changes the cervical mucus, which also makes implantation harder.
VIDEO: How much do you really know about birth control? Story continues after video.
Some people take the pill for other reasons, unconnected to pregnancy prevention. Some women with painful periods can benefit from preventing ovulation, which will make the uterine lining — and also menstrual bleeding — lighter. Stopping periods can help with endometriosis, and the reduced testosterone can also help with acne, among several other reasons it’s prescribed.
What it may mean
One reason teens might be susceptible to this possible side effect is that both the body and the brain change dramatically during the teenage years, Anderl said. “If you think about other substance use, many people would agree that teenage alcohol use might have a more harmful effect, for example, than alcohol use during adulthood,” she explained. “That’s simply because the brain develops so rapidly during those adolescent years.”
While the study does not definitively prove that taking birth control pills as a teenager makes it more likely that a woman will develop depression, the link is “definitely distressing,” Anderl says.
But she doesn’t think it means we should stop prescribing it. “Access to birth control is such an important and universal right, and it’s important that we do have access to birth control, especially as teenagers who might be at risk for teenage pregnancies,” she said.
For that reason, it’s important that teenagers talk to their doctors if they think they may already be at risk for depression, or if depression is a part of their family history.
As of 2015, nearly half of sexually active women in Canada who were trying to prevent pregnancy — 45.5 per cent — used oral contraception. And three quarters of Canadian women take the pill at some point in their lives.
There may not be a causal link, Anderl says, “but if there turns out to be one, it’s really important because so, so, so many women here in Canada and all over the world use the pill.”