go mad

verb3

1. •
   To become insane.

   • I feel certain that I am going mad again. I feel we cant go through another of those terrible times. And I shant recover this time. — 1941
2. •
   (informal) To do something extravagant.

   • Let's go mad and have a bottle of wine with our lunch.
   • Here's fifty pounds in case you see anything nice to buy, but don't go mad.
3. •
   (informal) To reach an excessive or ridiculous level.

   • Why should we ban controversial speakers from college grounds? Surely that's political correctness gone mad?