Therefore, the objectives of this study are (1) to explore consistent classes of NPS among patients with MCI using Latent Class Analysis (LCA); (2) to determine the effect of the resulting NPS classes on progression to dementia by means of a survival analysis; and (3) to investigate conversion to different types of dementia based on NPS classes accounting also for factors such as age, gender, level of education and/or APOE-Ɛ4. Here, APOE is linked to dementia.