If there is irrationality in the world, that doesn't mean that we have to be irrational to deal with it. Who do you trust as a psychiatrist? A doctor or a maniac?Your statement is without context... responding to "irrationality" depends on the nature of that irrationality. The harmless irrationality of one who converses with animals is quite different from the irrationality of one who seeks to destroy others because he believes it is the way of "truth" or the will of his diety (peace being when all who do not share his belief system are dead).
So, Mozza, your question is only valid if the irrational one is "treatable". The irrationality of the zealot, the defender of "truth", the one who believes innocents who do not share his beliefs must die... that is not treatable with psychiatry. That is treatable by sending the irrational one to meet the source of his "truth". If you think otherwise, state your "rational cure".