The PACO Study ("Personnalité Alzheimer COmportement")

Inclusion Criteria: * Male or female subject aged over 50 years ; * In-patient or out-patient at one of the centres participating in the study ; * Meeting all the diagnostic criteria for dementia due to AD (NINCDS ADRDA, CDR 1 or 2) or pre-dementia with a CDR of 0.5 (Berr et al., 2006, Dubois et al, 2007) ; * Covered by the state's Social Security system ; * With sufficient visual, auditory and oral and written French language skills to complete the clinical and neuropsychological evaluations ; * Accompanied by a caregiver in sufficient contact with the subject to be able to assess their personality and note the onset of changes in behaviour. Exclusion Criteria: * Patients with a progressive and/or poorly managed psychiatric pathology (patients with stabilised depression could be included in the study) ; * Patients taking any neuroleptic psychotropic medication ; * Patients taking other psychotropic medication, with the exception of any antidepressant, hypnotic, anxiolytic, acetylcholinesterase inhibitors or Memantine which has been prescribed and stabilised for more than 3 months * Patients with forms of dementia with an aetiology other than that of Alzheimer's disease (frontotemporal dementia, vascular dementia, Lewy Body dementia, and types of dementia that arise as a result of an underlying untreated disease, such as dysthyroidism, vitamin B12 or folic acid deficiency, syphilis, anaemia or hydroelectrolytic disorders) ; * Patients with serious, progressive or unstable pathologies which could interfere with the variables under consideration ; * Deafness or blindness which could compromise evaluation of the patient ; * Pregnancy ; * Patients under any type of guardianship or belonging to a restricted category as laid out in the Public Health Code ; * Patients without a suitable caregiver willing to participate.