Differences in prescription rates and odds ratios of antidepressant drugs in relation to individual hormonal contraceptives: A nationwide population-based study with age-specific analyses

Objectives To examine, among young women, the association of individual hormonal contraceptives, within two broad groupings, with antidepressant therapy. Methods In a nationwide register-based study, we examined the prescription rates of antidepressant drugs in relation to individual combined hormonal and progestin-only contraceptives among Swedish women aged 16-31 years (N = 917,993). Drug data were obtained from the Swedish Prescribed Drug Register for the period 1 July 2005-30 June 2008. Data on the total population of women aged 16-31 in 2008 were obtained from the Total Population Register of Statistics Sweden. The proportion of women using both hormonal contraception and antidepressants, and odds ratios (ORs) for antidepressant use for hormonal contraceptive users versus non-users, were calculated, the latter by logistic regression, for each formulation. Results The highest antidepressant OR in all age groups, particularly in the 16-19 years age group, related to medroxyprogesterone-only, followed by etonogestrel-only, levonorgestrel-only and ethinylestradiol/norelgestromin formulations. Oral contraceptives containing ethinylestradiol combined with lynestrenol or drospirenone had considerably higher ORs than other pills. ORs significantly lower than 1 were observed when ethinylestradiol was combined with norethisterone, levonorgestrel or desogestrel. Conclusion The association between use of hormonal contraceptives and antidepressant drugs varies considerably within both the combined hormonal contraceptive and the progestin-only groups.