How much sleep is enough? Study says focus on consistency, too.

The specific mechanism by which sleep timing affects overall mental health is still not completely understood, said Fang, the researcher who studied the medical residents. But the link between inconsistent sleep schedules and mental health outcomes may have to do with sleep quality, said David T. Plante, a psychiatrist and medical director of the Wisconsin Institute for Sleep and Consciousness at the University of Wisconsin-Madison.  “If you change the timing of when you’re sleeping, you can really affect the quality of your sleep,” he explained. Over time, “it can have a downstream effect on your overall well-being and mental health as well.”