"Go psycho" is an informal expression that describes someone becoming extremely angry, violent or losing control of their emotions. There are many synonyms for "go psycho" including "go berserk," "flip out," "freak out," "lose it," "go ballistic," and "go crazy." These expressions are used to describe someone's behavior when they experience an intense and sudden emotional outburst. "Go psycho" and its synonyms can be used to describe any kind of extreme behavior and can be used in a variety of contexts, such as describing a someone's behavior during an argument, or a person's behavior when they're under stress or anxiety.