An object of the present invention is to provide a therapeutic agent orprophylactic agent for Alzheimer's disease, which has an effect to inhibit ordelay theprogress of Alzheimer's disease and exhibits a long-lasting therapeutic effectonAlzheimer's disease even when used for a long period of time. The presentinvention provides a therapeutic agent or prophylactic agent for Alzheimer'sdisease,said agent comprising as an effective ingredient a cyclohexane derivativeexemplifiedby the formula below, or a pharmaceutically acceptable salt thereof or aprodrugthereof.(See above Formula)
