There are many synonyms for the phrase "go loony." Some commonly used ones include going crazy, going insane, losing one's mind, flipping out, and going bonkers. Other similar phrases include going off the deep end, going berserk, and losing one's grip on reality. All of these phrases are used to describe a situation where someone becomes irrational or loses control of their emotions. Whether caused by stress, anger, or mental illness, going loony is a serious issue that can have drastic consequences for those involved. As such, it's important to recognize the signs of someone who may be struggling and offer them the help and support they need.