thanks for using health care magic.
i have gone through your available history.
persistence of symptoms in your brother can be because of following:
1) non -compliance to treatment which is frequent in schizophrenic patients
2) Inadequate dosages of drugs
3) truly resistant schizophrenia
In any case You should consult Psychiatrist
In a non-compliance scenario, He may be benefited by Long acting injectable anti psychotic drugs or counselling
In second case, Adequate dosages has to be given.
In third case Elecetro-convulsive therapy (ECT) or drugs like clozapine
may be of some help.
I hope he will be fine soon.