Insanity, madness, lunacy, and craziness are behaviors caused by certain abnormal mental or behavioral patterns. Insanity can manifest as violations of societal norms, including a person or persons becoming a danger to themselves or to other people.
Contrary to popular belief, insanity isn't defined as doing the same thing over and over and expecting a different result. And, while it is often used to describe certain states of mind, insanity is also not a medical condition.
a form of insanity or dementia praecox that can appear at puberty, characterized by foolish behavior and deterioration of the mental faculties.