A new study by Danish researchers at the University of Copenhagen shows that your birth control pills might raise the risk of depression. The pills contain many hormones,
so the theory that birth control pills can increase depression has been floated before, but this new Danish study is one of the largest and most comprehensive looks into the subject to date. The study looked at health records for one million Danish women between the ages of 15 and 34. The study shows differences in rates of depression between types of hormone used, and also between oral or non-oral birth control. Women were grouped together based on whether they used hormonal contraceptives, including women who had done so in the previous six months, and those who do not. After over six years of following the women, an analysis of the data showed that the women using combination pills, that contain both estrogen and progestin, were 23 percent more likely than non-users to be on an antidepressant. But the numbers for women who took pills only containing progestin were even worse–34 percent more likely. Other, non-oral types of birth control also saw high rates of depression. According to the researchers that is probably because of the higher doses of hormones in those types of contraceptives.