Some synonyms for "goes loony" are: goes crazy, goes bonkers, goes bananas, goes berserk, goes off the rails, loses your mind, loses your marbles, goes insane, goes mental, has a breakdown, flips out, loses control, and goes over the edge. These phrases indicate an extreme and unpredictable reaction to a situation or stimulus. When someone goes loony, they may act erratically and irrationally, expressing emotions in an uncontrolled way. It is important to recognize the signs of a person who may be going loony and to offer them support and help when needed.