Doctors have long considered poor s

Doctors have long considered poor sleep to be a symptom of depression that would clear up with treatments, said Rachel Manber, a professor in the psychiatry and behavioral sciences department at Stanford, whose 2008 pilot trial of insomnia therapy provided the rationale for larger studies. “But we now know that’s not the case,” she said. “The relationship is bidirectional — that insomnia can precede the depression.”