This study was a prospective cohort study of patients diagnosed with mild cognitive impairment from February 2008 to January 2019. SNU institute approved the clinical study of patients based on The Nuremberg Code (1947) and FDA guidelines. We carried out all methods were carried out following relevant guidelines and regulations. The SNU Institute of Aging at Seoul National University approved all the experimental protocols. We administered medicines in compliance with medical and pharmacist laws under the informed consent of the patient.