Vancouver, British Columbia—Is it possible that women who used oral contraceptives (OCs) during adolescence raise their risk of developing depression as adults?

A new study published in the Journal of Child Psychology and Psychiatry raises that as a possibility. University of British Columbia researchers found teenage birth control pill users were 1.7 times to three times more likely to be clinically depressed in adulthood, compared with women who started taking birth control pills as adults, and to women who had never taken birth control pills.

The researchers tout their study as the first to look at oral-contraceptive use during adolescence and its possible relationship with women‘s long-term vulnerability to depression. “Our findings suggest that the use of oral contraceptives during adolescence may have an enduring effect on a woman’s risk for depression—even years after she stops using them,” said first author Christine Anderl, PhD, a UBC psychology postdoctoral fellow. “Adolescence is an important period for brain development. Previous animal studies have found that manipulating sex hormones, especially during important phases of brain development, can influence later behavior in a way that is irreversible.”

To reach those conclusions, the study team focused on 1,236 women in the United States National Health and Nutrition Examination Survey, for whom information on depression and age at first OC use was publicly available.

Women who reported first use of OCs in adolescence were compared with women who had never used OCs, as well as women who had first used OCs in adulthood. The outcome was 1-year prevalence of major depressive disorder (MDD), as assessed by trained interviewers.

Results indicated that, compared with women who had used OCs during adolescence, women who had never used OCs were less likely to meet the criteria for MDD within the past year in adulthood [odds ratio (OR) = 0.31, 95% CI, 0.16-0.60]. Similar results were documented for women who only started using OCs in adulthood (OR = 0.54, 95% CI, 0.30-0.95).

Researchers noted that factors that have previously been proposed to explain the relationship between OC use and depression risk—e.g., age at sexual debut, and current OC use—did not account for the results in propensity score analyses.

“We show a long-term association between adolescent OC use and depression risk in adulthood regardless of current OC use,” study authors conclude. “Our findings suggest that adolescence may be a sensitive period during which OC use could increase women’s risk for depression, years after first exposure.”

“Millions of women worldwide use oral contraceptives, and they are particularly popular among teenagers,” explained senior author Frances Chen, PhD, a UBC psychology associate professor. “While we strongly believe that providing women of all ages with access to effective methods of birth control is and should continue to be a major global health priority, we hope that our findings will promote more research on this topic, as well as more informed dialogue and decision-making about the prescription of hormonal birth control to adolescents.”

Background information in the articles points out that oral contraceptives contain synthetic forms of estrogen and/or progestogen, while suppressing the endogenous production of estrogen, progestogen, and testosterone “and may, therefore, alter a woman’s vulnerability to depression. Such hormone-induced changes may be particularly pronounced in adolescence, a life period that is characterized by intensive social, cognitive, reproductive and physiological development.”

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