The CIRCAME study examines how the body’s natural clock, called the circadian rhythm, and other factors like age and health, relate to memory problems. It looks at different kinds of dementia, such as Alzheimer's (AD), Lewy body dementia, vascular dementia, and frontotemporal dementia. The study is in Paris and involves 1,500 patients from two memory clinics. Researchers will check how these factors might help doctors diagnose and understand dementia better. They will also look at how dementia progresses over time, up to 15 years.

• Participants must be 18 or older and part of the French social security system.
• Participants must not have skin allergies to plastic or psychiatric disorders that explain memory problems.
• The study will last up to 15 years, tracking changes in memory and daily living abilities.

Participants will wear a wrist device to track their activity and sleep, and some will have eye and ear tests. They will visit the clinic for routine check-ups to see how their condition changes over time.