Definition - What does Insanity mean?
Insanity is a state of extreme derangement or unsoundness of mind. Legally speaking, being declared as insane can remove one from the responsibility of committing a crime. In these cases, the individual is presumed to be so psychologically unfit to the point that they are not capable of understanding or adhering to the law. Insanity can also prevent a person from being deemed suitable to sign his or her own legal contracts.
Justipedia explains Insanity
Insanity is often used as a defense in criminal law. In such cases, defense attorneys will claim that their clients cannot be held accountable for the crime because they are "insane" or psychologically unfit to be responsible for their own actions. In order to be considered insane, the defendant must exhibit clear signs of extreme mental illness. Medical professionals in the fields of psychology and psychiatry are often consulted to help clear up such matters. The opinions and conclusions drawn from such professionals can be of great use to the court when insanity is a relevant issue for the trial.
It is not easy to receive the verdict of "Not guilty by reason of insanity." It is important to note that simply having a mental illness does not make a person insane in the eyes of the law.