Disclosed are a therapeutic agent and preventative agent for Alzheimers disease having an inhibiting or delaying action on the progress of Alzheimers disease and maintaining a therapeutic effect on Alzheimers disease even with long-term administration. Specifically disclosed are a therapeutic agent and preventative agent for Alzheimers disease that contain a cyclohexane derivative represented by the formula, a pharmacologically acceptable salt thereof, or a prodrug thereof as the active ingredient.
