Mental illness is not a pathological concept, but a sociological concept. If a person is forcibly committed to a mental hospital by a family member or authority, that person can almost only be diagnosed as a Mental patient. The description of his symptoms by his family and authority is an important piece of information for judging whether he is mentally ill or not. And if he says he was persecuted and fought back, he fits the criteria of the psychiatric diagnosis of Paranoia, Maniaand the like. His right to self-defense is also nullified by this invincible logic: you say that you are not mentally ill, and you are, precisely at this time, because you refuse to admit that you are mentally ill -- a manifestation of mental illness; And you admit it, of course you are.
The option that can be inferred is that family members or authorities send someone to a mental hospital just to get him timely and effective treatment.