I'm pretty sure that you meant dementia (spelling is hard sometimes :)). If so, yes. Dementia is a mental condition that is most commonly "found" in older people. They can have memory loss, confusion and other things that have to do with mental decline. And yes, people with dementia need to have somebody to care for them because of their mental decline and possible physical disabilities that they may have due to the dementia or simply their old age. Its not curable but there are medications that can help improve mental stability.
~I hope I was able to help! Stay safe :)~