The invention disclosed herein is for an in vitro cell-based assay for predicting the conversion from mild cognitive impairment to Alzheimer's disease in a patient who has received a diagnosis of MCI. The method comprises the following steps: a) culturing human hippocampal progenitor cells in a culture medium comprising serum, obtained from said patient, during a period of proliferation of said progenitor cells; b) subsequently culturing said hippocampal progenitor cells in a culture medium comprising serum, obtained from said patient, during a period of differentiation of said progenitor cells; c) determining the level of proliferation of said cultured progenitor cells; d) determining the average cell count of said cultured progenitor cells; and e) monitoring apoptotic cell death after differentiation of the proliferated hippocampal progenitor cells, wherein the outcomes of each of (c) to (e) are applied to a statistical analysis, the result of which is predictive of conversion from MCI to AD in the patient.