How weary, stale, flat and unprofitable seem to me all the uses of this world! ...
Eric Kandel's classical Neuroscience textbook used to introduce the chapter on Major Depression and Bipolar Spectrum Diseases (they weren't called this way at the time), with this citation from Shakespeare's Hamlet (or possibly another similar one).
I have always considered this a particularly clever introduction because it guides the student in neuroscience to realize that psychiatric diseases are not characterized by particularly absurd emotional, mood, or cognitive attitudes and/or reactions.
What characterizes "psychoses" is that such attitudes and reactions are not temporary and caused, but are persistent, uncaused, pervasive, particularly intense and source of suffering and disability.
Actually, whether Hamlet was psychotic - major or bipolar depression? - or not is difficult to say, today (we do not even know whether prozac might have prevented the tragedy). In any case, his words could well be said by anybody (I mean, anybody possessing the poetic skills of the Bard) who is suffering of a reactive depression because of a loss, the death of a dear person or the runaway of his girlfriend. With no pathology.
Now, just think of whatever you can imagine a schizophrenic may say or do: wouldn't that make you laugh, if they only added, one moment after, "just kidding"...
And if anybody were to think you are serious, when you are joking, they would think you are crazy, except they might find the whole thing even more humorous the moment they realize you were indeed joking.
Irony and humor do create a tension, because they imply an unusual (inconsistent) way of looking at things, they play with paradox, or they may simply rely on the inconsistent use of an expression, an emotion, a tone, a kind of language, which is inappropriate to the situation.
And the relief of such tension - when we realize it is not "true" (or the guy was not really serious about that) - is a particularly pleasurable feeling.
Now imagine that same tension - something inconsistent in how you perceive the world, your own emotions, your sensations and feelings, your body, your thoughts - but nobody who says "just kidding", and you have a faint idea about what dissociation - and schizophrenia - may feel like.
Still, again, that sensation of inconsistency is there in irony and humor, is there when you let your fantasy fly free, when you are drowsy, when you dream: everything and the opposite of everything may be true, you can see yourself from the outside and in the mean time feel that the person you see there is you...
And in general all this is enjoyable.
How is so?
The question is that when the judgment of reality is released, inconsistency is no more a pain. It may even be a relief, it is a kind of an interlude, recreation time from the hard job of living...
But until you release that judgment, tension builds up. And when you finally realize the guy is just joking, you laugh and enjoy it.
Well, the problem in psychosis is nobody is joking.