Synonyms for the phrase "be insane" include "lose one's mind", "go crazy", "become deranged", "go mad", "have a breakdown", "be out of one's mind", "be demented", "be non compos mentis", "be a lunatic", "be unbalanced", "be mentally unstable", "be delusional", and "be psychotic". These expressions all refer to a state of severe mental disturbance or disorientation. They can be used to describe various types and degrees of insanity, from temporary or mild episodes to chronic or severe mental disorders. It is important to use language sensitively and accurately when talking about mental health conditions.