delirium

noun2

1. •
   A temporary mental state with a sudden onset, usually reversible, including symptoms of confusion, inability to concentrate, disorientation, anxiety, and sometimes hallucinations. Causes can include dehydration, drug intoxication, and severe infection.

   • The popular delirium [of the French Revolution] at first caught his enthusiastic mind. — 1824
2. •
   Wild, frenzied excitement or ecstasy.