The insanity defense has been with us a long time. The basic rule expressed in England in M'Naghton's Case (1843)* remains the law in much of the United States. As codified in 18 U.S.C. ยง17 (post-Hinckley): "It is an affirmative defense ... that ... the defendant, as a result of a severe mental disease or defect, was unable to
appreciate the nature and quality or the wrongfulness of his acts."
Modern courts have an issue that the Victorian courts did not, though. Many people with schizophrenia can be made sane for the time being with antipsychotic medication. These meds are a miracle of modern medicine, allowing many people who would otherwise have to be committed to institutions to live outside and have reasonably normal lives.
What happens when a person, while sane, chooses not to take the medication and then commits a crime a time when, for the moment and as a result of his earlier choice, he meets the insanity test? Some defenses can be lost when the defendant created the situation. The defense of self-defense, for example, can be lost if defendant is the initial aggressor in the incident.
George Maliha has an interesting student note in the current issue of the Harvard Journal of Law and Public Policy.
Modern courts have an issue that the Victorian courts did not, though. Many people with schizophrenia can be made sane for the time being with antipsychotic medication. These meds are a miracle of modern medicine, allowing many people who would otherwise have to be committed to institutions to live outside and have reasonably normal lives.
What happens when a person, while sane, chooses not to take the medication and then commits a crime a time when, for the moment and as a result of his earlier choice, he meets the insanity test? Some defenses can be lost when the defendant created the situation. The defense of self-defense, for example, can be lost if defendant is the initial aggressor in the incident.
George Maliha has an interesting student note in the current issue of the Harvard Journal of Law and Public Policy.
* Fans of the PBS series Victoria were treated to a dramatization of M'Naghten's crime in Season 2, Episode 6 a few months ago. The series is historical drama and not history, though. They took some liberties.

"The insanity defense is not based on the presence of illness ... the standard
in many states has become a simple cognitive test that has little relationship
to the scientific or clinical knowledge regarding psychotic illness. "
-- William T. Carpenter Jr., M.D.
This is arguably a "first world" elite concern, with ramifications for the lowly rest of us.
Culpability for violent and even murderous behavior may be legally lessened by all sorts of factors: youth, racism, homo/transphobia, insanity, drug consumption, emotional upset state of mind, educational deprivation, low intelligence,
abuse as a child, and more -- to be creatively constructed as we slouch
toward Gomorrah-- I am sure.
All are irrelevancies to us, the simplistic deplorables.
Lessened punishment equals compassion for the evildoer, rather than justice for the victim and compassion for the victim's family.
If someone tortures a 3-year old to death, does it matter whether his IQ is low?
And because a mass murderer chose to imbibe in drugs or alcohol,
he is to be held less responsible?
That is true immorality, or "insanity" if you wish.
Dr. Carpenter's statement regarding the insanity defense is not accurate. Four states have abolished the insanity defense, almost all the other states use either the M'Naghten test or the Model Penal Code test, both of which require the defendant to prove the presence of a mental illness/defect.