Association between duration of birth control pill use and risk of depression among US women.

ObjectiveTo explore the association between the duration of birth control pill use (DBCPU) and the risk for depressive symptoms among women in the United States.MethodCross-sectional data from 4996 American women obtained from the National Health and Nutrition Examination Survey, 2005-2012, were analyzed to evaluate the association between DBCPU and depressive symptoms using multivariate logistic regression models, fitted smooth curves, and subgroup and threshold analyses.ResultsStatistically significant differences (P < 0.05) were found for DBCPU, age at menarche, age stratification, race, and marital status. The adjusted weighted logistic regression model revealed a negative correlation between DBCPU and depressive symptoms. Subgroup analysis revealed that this association was stronger among women without diabetes. The restricted cubic splines plot indicated that the risk for depressive symptoms decreased as DBCPU increased. Threshold effect analysis identified an inflection point at 9.3, with a more significant risk reduction below this value (odds ratio 0.94 [95% confidence interval 0.90-0.98]; P = 0.006).ConclusionLong-term oral contraceptive use may be an effective intervention strategy for the prevention and treatment of depression in women; however, further prospective studies are needed to confirm this hypothesis.