The aim of the study SwissDEM is to assess aging - both physical and mental - and cognitive health among older adults in canton Zurich. Particular emphasis is placed on the impact of the SARS-CoV-2 pandemic and related federal regulations on the physical health, mental health, and cognitive functioning of older adults (≥65 years). Cognitive function will be evaluated by means of structured neuropsychological assessments. Furthermore, changes in activities of daily living and care needs will be assessed by short proxy interviews. The neurocognitive assessment is part of a national epidemiological study that will provide new insights into the incidence of dementia and aging in Switzerland.