Meaning of Ataoka(あたおか)

It means crazy or insane.
Ataoka(あたおか) is an abbreviation for “Atama ga okashii(あたまがおかしい)”.
It’s a slang and trend word (maybe still now) in young people.

Example Conversation

A: I hear Tanaka get into trouble with his client again.
B: Again?
A: He is really ataoka.

A: 田中がまた客ともめたらしいよ。
B: また?
A: あの人マジであたおかだからな。