Use of hormonal contraception is associated with the subsequent use of psychotropic drugs in women of reproductive age with a significant association in young adolescents and an insignificant association in adult women, according to the results of a study published in PLOS ONE.
Researchers designed a nationwide database by linking several Swedish registers. Statistics Sweden and the Swedish National Board of Health and Welfare constructed the database.
The investigators then identified an initial cohort containing all 1,094,069 women aged 12 to 30 residing in Sweden as of December 31, 2010. They obtained information on medication use from the Swedish Prescribed Drug Register. The baseline data was set as the first dispensed prescription of a hormonal contraceptive between January 1, 2010 and December 31, 2011. Women who did not have any hormonal contraceptive prescriptions during those 2 years were given a baseline date of December 31, 2010.
All women were followed-up at 1 year, and the researchers searched a period of 4 years prior to the baseline data to ensure that non-users of hormonal contraception were true non-users for the 4 years before and 1 year after their baseline data as of December 31, 2010.
The study included 815,662 women who had no previous psychiatric illness. The investigators followed the women from their first use of hormonal contraception until a prescription was filled for psychotropic drugs or the end of the 1-year follow-up. They performed age-stratified logistic regression models and estimated odds ratio (OR) to measure the association between different hormonal contraceptive methods and psychotropic drug use as well as the area under the receiver operating curve to estimate discriminatory accuracy of hormonal contraception with regard to psychotropic drugs.
The investigators found an association between hormonal contraceptives and psychotropic drugs with an adjusted OR of 1.34. In the age-stratified analysis, the strongest association was in adolescent girls (adjusted OR 3.46 for age 12 to 14), while it was non-existent for adult women.
The investigators concluded that hormonal contraception is associated with psychotropic drug use in adolescent girls. They suggested that this finding suggests an adverse effect of hormonal contraception on psychological health in this population.
Zettermark S, Vicente RP, Merlo J. Hormonal contraception increases the risk of psychotropic drug use in adolescent girls but not in adults: a pharmacoepidemiological study on 800 000 Swedish women [published online March 22, 2018]. PLOS ONE. doi:10.1371/journal.pone.0194773