- A butterfly flapping its wings can set off a hurricane.
- Birth control pills and patches cause depression.
Clearly, the birth-control-pill-depression connection seems plausible yet it is very similar to the butterfly example. It is a change in one thing that will travel over, under, around, and through many other complex systems, and lead to significant change in yet another system. (Kudos if you recognized the hurricane example from chaos theory.)
Yes, a recent study found that women taking birth control pills or using patches were more likely to also take antidepressants. Before we leap to birth control causes depression, let’s look at the not-very-simple context of women using hormonal birth control. One possibility, pointed out by Dr. Aaron Carroll in the New York Times, is that women using prescribed birth control are seeing a doctor to get it; if they have depression, it’s more likely to get diagnosed and treated.
Another possibility: sexually active adolescents may tend to be anxious and depressed. (Risk of antidepressant use was highest for adolescents in the study.)
Yet another option from a commenter on Carroll’s NYT article – Women who use birth control are closely involved with men. [Therefore], men are a leading cause of female depression.
The social factors that lead a woman to choose birth control pills or patches might overlap with those that cause women to be prone to depression.
Even more complex than the social factors is the biological process. Scientists know what contraceptive hormones do to the reproductive system; but tracing the pathway from those hormones to brain chemicals is likely not feasible. Even if we could, we do not know how depression affects the brain or why antidepressants work.
This is not to say that women’s depression is “all in their head” and therefore not worth addressing. Or that depression is a small price to pay for reliable contraception. It is to say that our desire for a quick and easy solution, a tweet-able answer, is doing ourselves a disservice. We are lured by the headline, “Birth Control is Making You Depressed”, not by the more accurate but boring “Some Birth Control Users Have Higher Likelihood of Also Using Anti-depressants; Scientists Ponder Why”.
With our current technology, we cannot untangle the social and biological factors that get triggered by medical care. Maybe we don’t have to. We can improve our effectiveness by recognizing and valuing the rich context that shapes our choices, our experiences, and even our bodies. More answers may lie in that muddle of complexities, than anywhere else.