PROBLEM TO BE SOLVED: To provide pharmaceuticals for central nervous system diseases caused by neurodevelopmental defects which result in excessive GABAergic inhibition in the cortex and hippocampus.SOLUTION: The present invention relates to the use of selective GABA A α5 negative allosteric modulators for the treatment, prevention and/or delay of progression of central nervous system (CNS) diseases. The modulators are compounds represented by formula (I) or compounds represented by formula (II).SELECTED DRAWING: None【課題】皮質及び海馬における過剰GABA作動性阻害をもたらす神経発達異常によって引き起こされる中枢神経系疾患のための薬剤の提供。【解決手段】中枢神経系(CNS)疾患の治療、予防及び/又はその進行の遅延のためののGABA Aα5ネガティブアロステリックモジュレーターの使用で、このモジュレーターが式(I)で示される化合物又は式(II)で示される化合物。【選択図】なし