In this book, the first time the author reported these four plants to have antidepressant activity due to the presence of different active molecules, which act in a synergetic manner. Forced swim stress (FST) was used to developed depressive-like behavior in rats, Thus, polyherbal extract possesses antidepressant action demonstrated by modulation of the serotonergic pathway, MAO receptors, acetylcholine, noradrenalin, and melatonin in rats.