DIV-AD BARCELONA: Alzheimer's Blood-Based Biomakers for a Diverse Community

INCLUSION CRITERIA * Cognitively Unimpaired individuals aged between 50 and 75 years at the time of signing the informed consent * Individuals interested in participating, able to follow study procedures, and who understand that all the tests are carried out in a research context. * Explicit desire to participate in the tests and procedures of the study, including: collection of study variables, cognitive and neurologic assessment, blood sampling. * Signing the informed consent, agreeing not to receive the research results that will not be of no clinical interest for the participant. EXCLUSION CRITERIA * Cognitive decline defined by CDR\>0. * Individuals with cognitive complaints and who have sought for medical help for cognitive impairment at any time in their life * Patients with relevant medical illnesses that may significantly interfere with the interpretation of results. This includes auditory and visual perception disorders, active oncological disease under treatment (localized tumors are excluded) and any condition that, in the investigator's opinion, may interfere with the correct performance/interpretation of the study procedures and/or with future permanence in the study. * Major psychiatric disorders (according to the DSM-V manual) or diseases that affect cognitive abilities (major depressive episode, bipolar disorder, schizophrenia, etc). * Acquired brain damage: history of head trauma with macroscopic parenchymal or non-axial lesion, large-vessel ischemic or hemorrhagic stroke, brain tumours and any other etiologies that can cause acquired brain damage (i.e., chemotherapy or brain radiotherapy). * Parkinson's disease, epilepsy under treatment and with frequent seizures (\> 1/month) in the last year, multiple sclerosis or other neurodegenerative diseases.