How do birth control pills change the brain?

The largest brain imaging study of a woman to date shows that hormonal birth control can decrease brain volume – though it isn’t clear what effect, if any, this has on brain function.

Hormonal contraceptives have been around since the 1960s. Yet scientists only began investigating their potential effects on the brain in the past decade or two, says Carina Heller at the University of Minnesota. Previous studies have shown differences in brain volume between women who take hormonal contraceptives…