Herb Research Foundation

According to a small Swiss pilot study of 14 depressed patients, ginkgo boosts cognitive-psychomotor performance, reduces the number of nighttime awakenings, and increases both short wave and slow wave sleep. Over a six-week period, half of the subjects took a prescription antidepressant, and the others took ginkgo (source does not specify dosage). Although researchers do not understand the precise mechanism of action, laboratory studies indicate that ginkgo causes a down-swing in stress hormone activity. Researchers at Switzerland's Basel Psychiatric University plan to confirm the results in a larger randomized, double-blind trial.