The purpose of this study is to investigate the influence of the APOE genotype on brain morphology, function and metabolism, related to other factors such as cognitive reserve, cognition and episodic memory, in subjects at greater risk of developing AD.

The purpose of this study is to investigate the influence of age and the APOE genotype on brain morphology and function, in 700 cognitively healthy individuals, 45 to 75 years old, recruited from an ongoing longitudinal cognition study exploring memory and executive functions (ClinicalTrials.gov ID: NCT01835717).

All subjects have been APOE genotyped and underwent a clinical and cognitive assessment. Within this study, the subjects will be submitted to an MRI scanning protocol including morphological and resting state acquisitions. An identical follow-up MRI session will be performed in 2 years' time. The analyses will be focused on detecting the effect of the APOE allelic variants on the change rate of the neuroimaging variables as well as its interaction with aging.

Inclusion Criteria:

• Participant included in the study ClinicalTrials.gov ID: NCT01835717
• APOE genotype obtained before MRI acquisition
• Be willing to perform an MRI and agree to a 2 years longitudinal follow up
• Sign informed consent

Exclusion Criteria:

• Contraindication to MRI scanning: claustrophobia, pacemaker, history of ocular cerclage, heart valves, aneurysm clips and carrying any metal prosthesis incompatible with MRI.
• Incidental MRI findings that result in the images not being included in the study.

The population of this study is 45 to 75 years old at the time of inclusion in the parent study (ClinicalTrials.gov ID: NCT01835717), mostly sons and daughters of AD patients.