A new study out of Stockholm says that women who use birth control pills may live at an increased risk for ill health and poor quality of life. No increase in depressive symptoms, however, was observed, providing a measure of calm to scientists who have suspected that oral contraceptives can increase the rate depression diagnoses in women.

Oral Contraceptives Show Negative Mental Effects

The double-blind study, conducted by researchers at Sweden’s Karolinska Institutet, followed 340 healthy women between the ages of 18 and 35 for a total of three months. Half of the women were given a course of placebo tablets, while the remaining 170 received a combination contraceptive pill.

Birth Control Pill Risk Infographic

Those women who took birth control pills reported a significantly lower general quality of life than women who received the placebo. Moreover, the contraceptive patients reported negative effects for several specific aspects of mental and physical health, including mood, impulse control and energy level. The observed decrease in quality of life could go some way to explain why many women discontinue the use of oral contraceptives. As study author Niklaus Zethraeus noted, “this might in some cases be a contributing cause of low compliance and irregular use of contraceptive pills.”

Unintended Pregnancy Statistic Infographic

In 2008, a report from the Guttmacher Institute estimated that up to 43% of unintended pregnancies could be attributed to inconsistent or incorrect contraceptive use.

Widely-Used Combination Pill

The contraceptive used in the study relies on a combination of two hormones, ethinyl estradiol and levonergestrel, to prevent pregnancy. This is the most common combination pill used in Sweden and is widely-prescribed in the United States. Sold under multiple brand names, the hormone combo can be found in numerous pills, from Altavera and Enpresse to Levora and Portia. The study’s findings don’t say anything about other forms of oral contraception, which will need to be judged by their own merits.

While considered statistically significant, the contraceptive’s health effects were fairly minor and the Swedish researchers have advised caution. Healthcare professionals and patients should not assume that the potential ill effects of birth control are enough to outweigh the benefits. That being said, we still know less about the short- and long-term risks of oral contraception than we should.

Lack Of Birth Control Research Frustrates Researchers

Lead author Angelica Lindèn Hirschberg, a professor in the Karolinska Institutet’s Department of Women’s and Children’s Health, says, “we know surprisingly little today about the pill’s effect on women’s health.” The scientific evidence to support the safety of oral contraceptives is thin, Hirschberg notes, even though an estimated 100 million women around the world rely on the pill as their primary form of birth control. More research is desperately needed.

Oral Contraceptive Usage Infographic

Depression Link Remains Unclear

Previous results have not quieted the concerns of patients and health care advocates. In 2016, a team of Danish researchers published in the Journal of the American Medical Association their results from a 13-year review of more than 1 million women.

Correlating the use of birth control pills to rates of depression diagnosis, the study found that women on combined pills were about 23% more likely to begin using antidepressants than women in the general population. Patients who took progestin-only pills had an even higher risk, about 34%, while users of a contraceptive patch were nearly twice as likely to be prescribed depression medications. Again, these are small elevations in a risk that should not dissuade healthy women from taking their prescribed medications. In addition, the likelihood of depression appears to decrease with age, a signal that more long-term research should be performed.

For now, the researchers have begun to advocate, hoping that doctors will begin to take the potential adverse consequences of oral contraception into account in their prescribing decisions.