To provide an efficient method for retarding the progress of Alzheimer's disease known as a form of dementia developing progressive neurodegeneration of a subject, completely losing recognition ability and causing early death.

This invention relates to a composition and a method for the treatment of cognitive deficit such as Alzheimer's disease. The disease can be treated by administering the subject with an active amount of the 1st compound comprising phenserine or its pharmacologically permissible salt, an active amount of the 2nd compound comprising an HMG-CoA (β-hydroxy-β-methylglutaryl CoA) reductase inhibitor or its pharmacologically permissible salt selected from atorvastatine, rivastatin, mevastatin, lovastatin, pravastatin, velostatin, fluvastatin, simvastatin and their combination, and the 3rd compound comprising (+)9-N-phenylcarbinol esurolin.