This is a prospective, multicenter study designed to evaluate the benefits of an evening music-based intervention on sundowning syndrome in patients with Alzheimer's disease or related disorders in a Protect lLife Unit setting.

This study will employ a randomized, cluster-organized, crossover design to compare the effects of a music-based intervention (TEST) with an audiobook listening intervention (CONTROL). Both interventions will be delivered by a therapist in the participants' living environment over ten evening sessions per intervention period. Each participant will serve as their own control and will be exposed to both intervention conditions. The sequence of intervention periods ("TEST followed by CONTROL" or "CONTROL followed by TEST") will be randomized at the cluster level within participating protected care units (UVP). Behavioral and actigraphic outcomes will be collected and analyzed at baseline, during, and after each intervention period.

Inclusion Criteria:

• Signature of consent by the patient's legal guardian obtained after providing information
• Patients aged 60 and over who meet the diagnostic criteria for Alzheimer's disease and related disorders, including mainly: Lewy body disease, frontotemporal lobar degeneration, progressive supranuclear palsy, corticobasal degeneration, vascular encephalopathy, alcoholic dementia, primary progressive aphasia syndrome, posterior cortical atrophy syndrome (France Alzheimer, 2024).
• Patient living in a secure care unit
• If taking psychotropic drugs, they must have been stable for 3 months
• If taking level 2 or 3 painkillers, they must have been stable for 1 month

Exclusion Criteria:

• Refusal to participate
• Participation in a study on a drug/medical device/treatment technique that may affect sleep or behavior.
• Highly sedated patients,
• Patients with acute medical instability,
• Patients with productive delusions,
• Patients who have been in the unit for less than 1 month