Mania, n.
Etymology: [L. mania, Gr. manie, F. manie. Cf. Mind, n., Necromancy.]
1. Violent derangement of mind; madness; insanity. Cf. Delirium.
2. Excessive or unreasonable desire; insane passion affecting one or many people; as, the tulip mania. Mania a potu Etym: [L.], madness from drinking; delirium tremens.
Syn. -- Insanity; derangement; madness; lunacy; alienation; aberration; delirium; frenzy. See Insanity.
Shades of meaning
Fernald has no entry of its own for mania; he lists it under insanity.
Where he writes about it:
Madness is the old popular term, now less common, for insanity in its widest sense, but with suggestion of excitement, akin to mania. — from insanity
Frenzy and mania are forms of raving and furious insanity. — from insanity