There is no association between combined oral hormonal contraceptives and depression: a Swedish register-based cohort study.

Objective: To investigate whether users of hormonal contraceptives (HCs) are at increased risk of depression compared with non-users.

Design: Register-based cohort study.

Setting: Sweden.

Sample: Women aged 15-25 years between 2010 and 2017 with no prior antidepressant treatment, psychiatric diagnose or contraindication for HCs (n = 739 585).

Methods: Women with a prescription of HC were identified via the Swedish Prescribed Drug Register (SPDR). Relative risks (RRs) for first depression diagnosis in current HC-users compared with non-users were modelled by Poisson regression. Adjustments included age, medical indication for HC-use and parental history of mental disorders, among others.

Main Outcome Measures: Depression, captured by a redeemed prescription of antidepressant treatment, or a first depression diagnosis in the SPDR and the National Patient Register.

Results: Compared with non-users, women on combined oral contraceptives (COCs) and oral progestogen-only products had lower or no increased risk of depression, relative risk (RR) 0.89 (95% CI 0.87-0.91) and 1.03 (95% CI 0.99-1.06) after adjustments, respectively. Age-stratified analyses demonstrated that COC use in adolescents conferred no increase in risk (RR 0.96, 95% CI 0.93-0.98), whereas use of progestogen-only pills (RR 1.13, 95% CI 1.07-1.19), contraceptive patch/vaginal ring (RR 1.43, 95% CI 1.30-1.58), implant (RR 1.38, 95% CI 1.30-1.45) or a levonorgestrel intrauterine device (RR 1.59, 95% CI 1.46-1.73) were associated with increased risks.

Conclusions: This study did not find any association between use of COCs, which is the dominating HC in first time users, and depression. Non-oral products were associated with increased risks. Residual confounding must be addressed in the interpretation of the results.

Tweetable Abstract: There is no association between combined hormonal contraceptives and depression.