Is there a word for the mental state of laughter?

We speak of madness when someone is in a fit of anger, and being smitten when someone is in love(with someone), etc. But what about when someone just can't stop laughing? i.e, when someone is "cracking-up" - is there a more formal word?


Solution 1:

We speak of hysterical laughter.

Solution 2:

Hilarity

Solution 3:

They are amused. Defined as being entertained by something.