Other than the disgusting factor (more on that below), a bad mattress can lead to awful sleep, which can affect GPA, among other things. According to a report from American Academy of Sleep Medicine, “the lack of adequate nighttime sleep can lead to disturbances in brain function, which in turn, can lead to poor academic performance,” says Clete A. Kushida, MD, Ph.D., director of the Stanford University Center for Human Sleep Research.