Not getting enough sleep, at least seven hours each night, has been linked to physical and mental health issues, like cardiovascular disease and depression. But one-third of American adults suffer from insomnia. Surprisingly, a new study in the journal Nature Human Behavior found that women struggle with sleep more than men. And they are more likely to take sleep medications than men. It’s not clear why. Hormones might play a role. But women have also been shown to more often struggle with an overactive bladder or restless leg syndrome, which could make sleep difficult.