The present invention relates to an anti-depression drug containing at least one compound selected from a branched amino acid, a pharmacologically acceptable salt thereof, and their derivatives as an active ingredient.本發明係有關含有從支鏈胺基酸、其藥理學上所容許之鹽、及該等之衍生物中選出之至少1種以上之化合物做為有效成分的抗憂鬱劑。該代表圖無元件符號及其所代表之意義。