How to title a brokerage account for a couple if one spouse is disabled and incompetent?

I am trying to find out the best way to title a brokerage account for a friend whose wife has Alzeheimer disease. He has bank accounts which are now held as joint tenant with his wife. He is not sure if he should do the same for a brokerage account he is going to open.|||no he should just open it in his name and maybe one of the children's name!!!