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.