These correlational findings do not prove that lack of sleep is causing these problems. Certainly the reverse can be true: depression and anxiety can cause insomnia. “But the majority of the research evidence supports the causal direction being lack of sleep leading to problems rather than the other way around,” says study co-author Adam Winsler, a psychology professor at George Mason University. Sleep deficits reduce brain function, further disturbing areas in which even well-rested adolescents struggle: executive function, self-control and judgment. “Parents, educators, and therapists need to pay attention to the role of sleep in preventing mental illness among youth,” Winsler says. “Its effect is likely larger than most therapies and medications.”
