If someone is seriously delusional, does this make the mentally ill, or is it just a sign they might be?
Define Delusional a bit more. Wacky Ideas ala David Icke with the 7 ft lizard people (although I do follow other aspects of his ideas) or living in a constant acid trip.
I've been called delusional many times for simply having a different perspective over something. "You're delusional". So no, it doesn't necessarily mean you have a mental problem, but the person accusing you of such a thing might just be a **** face. Lulz.