Usage patterns
〈人〉が認知症になるfor someone to develop dementia
My grandfather developed dementia after he turned eighty.
認知症と診断されるto be diagnosed with dementia
My mother was diagnosed with dementia last month.
認知症を発症するto develop (the onset of) dementia
The risk of developing dementia increases with old age.
認知症を予防するto prevent dementia
Moderate exercise is said to help prevent dementia.
認知症の人を介護するto care for a person with dementia
She works taking care of people with dementia.
認知症の症状が出るfor symptoms of dementia to appear
Recently, my father has started showing symptoms of dementia.
