Comment by Gravityloss

There's angles to socialization. If a person with brain issues gets free doctor visits and a medicine, that is at cost to society.

If they are safe to be around and are able to hold a job or have children, then there's societal benefits gained. One could consider the treatment costs as investments.

If that person was untreated and they did something unpleasant or bad in public, or ended up in prison, that also has a cost to society though it might be more complex to quantify.