This is a 2-year, multicenter, prospective (look forward using periodic observations collected predominantly following patient enrollment), longitudinal (it is a co relational research study that involves repeated observations of the same variables over long periods of time), and observational study. The objective of this study is to examine the patients with mild and moderate AD who are currently being treated with different treatment care methods in real-world settings. Doctors will not be provided medication or asked to treat their patients with any particular treatment. The effect of the different management strategies on cognition, activities of daily living, and behavior of the patients will be evaluated, and data on the informal caregiver burden will be assessed. Data on the utilization of health and social care services by the patient and the primary informal caregiver, including admission of the patient to an assisted living facility or nursing home will be assessed. The doctor's assessment of clinical global impression and adverse events will also be documented. Data will be collected from the doctors at baseline and at 6, 12, and 24 months, and from the caregivers at baseline and 6, 12, 18, and 24 months. The medication dosage and administration is based upon the doctors' prescription, individualized for the patient and not dictated by the protocol.