⁃ AD patients:

• Probable Alzheimer's disease (clinical and biological NINCDS-ADRDA 2011 criteria)

• Mild-moderate AD (MMSE ≥15)

• Sufficiently fluent in French in order to answer study questionnaires

• Agrees to undergo medical examinations at baseline, 12 and 24 months, as outlined in the protocol

• Affiliated to French social security

• Written informed consent

⁃ Caregivers:

• Caregiver (defined as assisting the patient in activities of daily living for at least 6 hours per week during the last 6 months) to an AD patient having agreed to participate in the study

• Age ≥18 years.

• Sufficiently fluent in French in order to answer study questionnaires

• Agrees to answer regular questionnaires about their own or the AD patient's health (during visits at study centres or via a secure internet website/postal questionnaires)

• Affiliated to French social security

• Written informed consent

⁃ First-degree relatives:

• First degree relative of an AD patient having agreed to participate in the study

• Age ≥18 years.

• Sufficiently fluent in French in order to answer study questionnaires

• Agrees to undergo medical examinations at baseline, 12 and 24 months, as outlined in the protocol

• Agrees to answer regular questionnaires about their own health (via a secure internet website or via postal questionnaires)

• Affiliated to French social security

• Written informed consent

⁃ In order to be included in the study, a familial cluster must be comprised of 2 to 5 people, as follows:

• Familial cluster of 2 people: 1 AD patient and 1 first-degree relative who also meets the caregiver inclusion criteria, OR

• Familial cluster of 3 to 5 people: 1 AD patient, 1 caregiver (does not need to be a relative of the patient), 1 to 3 first-degree relatives of the patient