Nouns

(n)madness, rabidity, rabidnessunrestrained excitement or enthusiasm“poetry is a sort of divine madness”
(n)rabidityThe property of being very extreme, unreasonable, or fanatical in opinion; excessively zealous; comparable to one with rabies.“Ten years since Joss Whedon's western-in-space cult classic Firefly went off the air, the rabidity of its fandom, better known as the Browncoats, hasn't waned at all.”