The present invention relates to a preventive and/or therapeutic agent for psychoneurotic diseases, comprising an EP
3
antagonist represented by the general formula (I):
(wherein the meanings of characters are defined in the description). This compound has an antagonistic potency against EP
3
and exhibits efficacy through unusual action mechanism as a preventive and/or therapeutic agent for psychoneurotic disorder, psychosomatic disorder, anxiety disorder, depression and disorder caused by stress.