The US used to have big mental hospitals for the mentally defective. Those were phased out in the Reagan era.[1][2] They didn't cure many people, but they fed and clothed them, and warehoused them out of sight, so everyone else could get on with life.

[1] https://www.npr.org/2017/11/30/567477160/how-the-loss-of-u-s...

[2] https://www.thebalance.com/deinstitutionalization-3306067