There are such groups. The best way to find out what is in your community is through the social worker at the hospital where he was treated. He or she might also have some other resources to help. Its a very tough problem. Every state has different laws but there is possible a way that treatment can be mandated by the court.
What means delusions? Please explain.
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Your brother does not need a psychiatry. not medication, also.
Probably not much help, but hopefully somewhat supportive.