Valerian root has been used in Europe for thousands of years to fight the blues as well as anxiety and insomnia. It's also prescribed as a sleep aid in lieu of sedatives such as halcion and valium. In Germany, based on clinical trials and other studies, the extract is considered an official sleep aid, while here in the U.S., people are still dubious. The flowering plant has been used by healers from ancient Rome to Greece to India for its mood-lifting and anxiolytic effects. Unlike many other herbs, this one has to be taken for several weeks or months until positive benefits are experienced.