Effects of Deer Bone Extract NS on Improvement in Cognitive-Bio-Markers of Cognitive Functions

Inclusion Criteria: * Age between 40 and 65 years old, * Global Deterioration Scale score (GDS) of 2 * High school or higher levels of education. Exclusion Criteria: * Current pregnancy or breast-feeding * Evidence of neurologic or medical conditions * Axis I diagnosis when assessed by the board certified psychiatrist using the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorder, 4th edition (DSM-IV)(SCID-IV), * One or more major depressive episode during last 12 months * Mini-mental status examination score of 24 or less * Clinical Dementia Rating score of 0.5 or more suggesting cognitive impairment beyond self-perceived subjective deficits * Intelligence quotient less than 70 * Any history of head trauma involving loss of consciousness or seizure * Contraindications to magnetic resonance imaging (MRI) * Use of psychotropics in last 3 months * Use of oral contraceptive medication * Participation in other clinical trials during the study period that might affect the outcome of the present study.