depends on.

It is true that he need not pay if he cann't pay. But the mental hospital in U.S. won't take patients in unless they try to suicide or kill other people. Welfare fund is limited, the hospital won't give the best and expensive medication if they know the person doesn't have insurance and cann't pay. Not all doctor want to take patients if they are uninsured and poor. It happens to one of my friends, the medication she tried can not help. They want to go to the best doctor and try the most expesive medication, but the doctor refuse them since they don't have insurance and won't pay at all.