Association between Oral Contraceptive Usage and Depressive Symptoms in Korean Women

Background Oral contraceptives—widely used by women for both reproductive and non-reproductive health reasons such as menstrual regulation, mood stabilization, and acne treatment—vary in type (including combined estrogen-progesterone, progesterone-only, and continuous use oral contraceptives). Usage of oral contraceptives can involve potential negative side effects. Mood changes are among these effects, including depressive symptoms. This study aims to address the gap in research on side effects of oral contraceptives by examining the association between oral contraceptive use and depressive symptoms in adult women in South Korea. Methods This study used data from 2007–2022 from the Korea National Health and Nutrition Examination Survey (KNHANES). Focusing on female respondents aged 18 and older, the final analysis included 15,000 women. Depressive symptoms were measured using the Patient Health Questionnaire-9 (PHQ-9). The main independent variable was oral contraceptive use for longer than one month. A multiple logistic regression model assessed the association between contraceptive usage and depressive symptoms, presenting results as adjusted odds ratios (aORs) and a significance threshold of p < 0.05. All analyses were conducted using SAS version 9.4. Results Of the 15,000 respondents, 2,573 women reported oral contraceptive usage for longer than a month. Among non-users, 6.3% had depressive symptoms, compared to 9.7% of women who reported using oral contraceptives. Women using contraceptives for over a month had higher odds of reporting depressive symptoms (OR = 1.65, 95% CI 1.37–1.98). Subgroup analyses showed elevated odds for depressive symptoms across various demographic categories, with unmarried women (aOR = 2.20) and those without pregnancy experience (aOR = 2.03) showing notably higher risks (compared with married women aOR = 1.42, and women with pregnancy experience aOR = 1.45). The multiple logistic regression also indicated that women who reported using oral contraceptives for one month or longer were more likely to experience moderate to very severe depressive symptoms, with statistically significant associations found only for moderate and higher depressive symptom levels (aORs ranging from 1.66 to 1.92). Conclusion The study found that women using oral contraceptives were at higher risk for depressive symptoms. Subgroup analyses suggested that of these women, unmarried women and women without pregnancy experience were at highest risk for developing depressive symptoms. This suggests that healthcare systems should monitor women using oral contraceptives and patients should be advised to consider the possibility of depressive symptoms.