Chronic insomnia is a major public health problem. And too many people are using__1__ therapies,even while there are a few treatments that do work. Millions of Americans __2__awake at night counting sheep or have a stiff drink or __3__an pill,hoping it will make them sleepy.__4__ experts agree all that self-medicating is a bad idea,and the causes of chronic insomnia remain__5__. Almost a third of adults have trouble sleeping,and about 10 percent have__6__ of daytime impairment that signal true insomnia. But __7__the complaints,scientists know surprisingly little about what causes chronic insomnia,its health consequences and how best to treat it,a panel of specialists __8__togethe