PROBLEM TO BE SOLVED: To obtain a memory disorder inhibitor comprising melatonin, its derivative or pharmacologically acceptable salt as an active ingredient.SOLUTION: The memory disorder inhibitor comprises melatonin, its derivative, its pharmacologically acceptable salt or their solvate.COPYRIGHT: (C)2007,JPO&INPIT【課題】記憶障害抑制剤の提供。【解決手段】 メラトニン若しくはその誘導体、その薬学的に許容可能な塩、又はこれらの溶媒和物を含む、記憶障害抑制剤。【選択図】なし