A study published last year in JAMA psychiatry has shed light on a question that has been posed over and over by patients and healthcare practitioners alike – does birth control increase one’s risk of depression?
Although it has long been suspected that hormonal birth control has a negative effect on mood (since the 1960s in fact!), previous research has provided mixed results. This is the largest study to date on the topic and the results are both convincing and concerning.
Literally millions of women worldwide are using hormonal contraceptives. The number affected by depression is also in the millions. In fact, depression is the most common psychiatric disorder. Therefore, finding out how these two things intersect is an extremely important topic to sort out.
Over one million Denmark women between the ages of 15 and 34 were followed for 14 years. Data on participants’ first use of hormonal contraceptives, type of contraceptive, onset of depression, and initiation of an antidepressant were gathered and analyzed. The findings were alarming, particularly for the adolescents on these meds. This younger age group was 80% more likely to be prescribed an antidepressant after beginning a combination (progesterone and estrogen) birth control and a whopping 120% more likely if they took a progestin-only pill. Overall, the ring and patch forms of hormonal birth control were even more likely to precede antidepressant use.
The study does not delve into the mechanisms that might be involved in this link between depression and hormonal contraceptives. But according to psychiatrist Kelly Brogan, there are a few plausible explanations based on previous research.
In one study, several different kinds of hormonal birth control raised sex hormone binding globulin (SHBG), which lowers the amount of thyroid hormones and testosterone in circulation. This can lead to symptoms of hypothyroidism, which include depression and low libido. These oral contraceptives also increased inflammatory markers like c-reactive protein. Inflammation is now well-recognized as an underlying cause of depression.
In another study, those taking oral contraceptives had higher levels of lipid peroxidation, which is a marker for oxidative stress. Oxidative stress leads to inflammation. These medications are also known to deplete vitamins and minerals, many of which have an impact on mood. For example, B6 is a co-factor in the production of the neurotransmitters serotonin and GABA. B6 is commonly depleted by oral contraceptives, along with zinc, magnesium, selenium, and CoQ10, just to name a few – here’s how oral contraceptives deplete vitamins.
Some critics might argue that prospective cohort studies like this one are still not as convincing as the “gold standard” double-blind, placebo-controlled study. Additionally, the percentages of increased risk of depression represent relative risk, not absolute risk. While these factors should be taken into consideration before ditching the pill, the findings of the Denmark study are still significant enough to warrant more caution and awareness surrounding the prescribing of these medications. The very large sample size, in addition to the plausible mechanisms of actions demonstrated in previous studies, make a strong case for hormonal birth control as a contributing factor in the development of depression and subsequent antidepressant use.
Those with a personal or family history of depression may be more at risk for this side effect, which may explain why some women report mood changes after starting the pill and others do not. But in light of other well-known side effects associated with hormonal contraceptives (increased risk of blood clots, headaches, weight gain, lower libido, etc), it may be time to revisit non-hormonal methods of birth control.
Non-hormonal methods are a better fit for many women, especially those concerned about depression or struggling with thyroid-related or other types of hormonal and metabolic imbalances. A few examples are non-hormonal IUDs, condoms, and fertility-based-awareness methods. Talk to your integrative medicine practitioner to determine what type of birth control is right for you.