@mpjgregoire
They would probably vote for their lobbygroups and have a voice. Voting with assistance is a normal thing in most countries, so I do not this.
IMHO it is a very slippery slope to tie voting to mental health. (especially since a nearly to neglect margin is to be expected to be excluded from voting)
covid deniers, climate science deniers and other science deniers are not rational either. So where to stop to exclude people?