You’ve probably heard someone say, “the definition of insanity is doing the same thing over and over and expecting different results.” That quote gets attributed to Albert Einstein, Benjamin Franklin, and Mark Twain, but none of them actually said it. It most likely came from a 1983 novel by Rita Mae Brown.
More importantly, that’s not what insanity means. Not medically, not legally, and not in any clinical sense. So what does insanity actually mean? And is it even a real condition? This article clears up the confusion.
The Short Answer
Insanity is not a medical diagnosis. You will not find it listed in the DSM-5 (the manual psychiatrists use to diagnose mental health conditions). The term “insanity” was retired from medical use over 100 years ago. Today, it is primarily a legal term used in courtrooms to determine whether a defendant understood what they were doing when they committed a crime. When people use the word “insanity” in everyday conversation, they’re usually describing behavior that seems irrational or extreme, but that’s a colloquial usage, not a clinical one.
Where Did the Word "Insanity" Come From?
The word has been in use since the late 1500s. For the first 200 years, it simply meant “the condition of being mentally deranged.” By the 1800s, it started being used more loosely to describe extreme foolishness or unreasonable behavior.
In medical history, “insanity” was once a catchall term for what we now diagnose as schizophrenia, bipolar disorder, psychosis, and other specific conditions. In 1921, the American Journal of Insanity changed its name to the American Journal of Psychiatry. By 1925, the word had been replaced in medical textbooks with more precise terminology.
So when someone asks “what is insanity,” the honest answer is that it depends on who you’re asking and in what context.
The Legal Definition of Insanity
In the U.S. legal system, insanity is an affirmative defense. It means that at the time a crime was committed, the defendant’s mental state prevented them from understanding what they were doing or knowing that it was wrong.
Most states follow one of these standards:
- The M’Naghten Rule: The defendant didn’t know the nature of their actions OR didn’t know their actions were wrong. This is the most common standard.
- The Model Penal Code Test: The defendant lacked “substantial capacity” to appreciate the wrongfulness of their conduct or to conform their behavior to the law.
- The Irresistible Impulse Test: The defendant couldn’t control their actions due to mental illness, even if they knew it was wrong.
- The Durham Rule: The crime was a direct “product” of mental illness. Only New Hampshire still uses this standard.
Despite what TV dramas suggest, the insanity defense is used in less than 1% of felony cases in the United States. It is not a loophole or an easy way out. Defendants found not guilty by reason of insanity are typically committed to a psychiatric facility, sometimes for longer than they would have served in prison.
The important distinction is that legal insanity is decided by a judge or jury, not by a psychiatrist. Mental health professionals provide evaluations, but the final determination is a legal one.
The Medical Perspective: Why Psychiatrists Don't Use the Word
Modern psychiatry does not use the word “insanity” as a diagnosis. According to the American Psychiatric Association, mental illnesses are diagnosable conditions that affect thinking, mood, and behavior. Each condition has specific diagnostic criteria outlined in the DSM-5.
What people historically called “insanity” would today be diagnosed as one or more specific conditions:
- Schizophrenia: Involves hallucinations, delusions, and disordered thinking
- Bipolar disorder: Causes extreme shifts in mood, energy, and behavior
- Psychotic disorders: Involve a break from reality, including delusions or hallucinations
- Severe depression with psychotic features: Depression accompanied by false beliefs or perceptions
These are real, treatable medical conditions with established diagnostic criteria and evidence-based treatments. Calling them “insanity” doesn’t help anyone understand what’s happening or how to get better.
At MindWell Psychiatric Services, we provide psychiatric evaluations that identify exactly what condition someone is dealing with so we can build the right treatment plan.
Is Insanity the Same as Mental Illness?
The short answer is no. Insanity is a legal concept. Mental illness is a medical concept. The two overlap in some situations, but they are not interchangeable, and confusing them contributes to harmful stigma around mental health treatment. We wrote a full breakdown of this distinction in our article on whether insanity is a mental illness, including why this confusion matters and how it affects people seeking help.
The Famous "Definition of Insanity" Quote
Since so many people search for this, let’s address it directly. The quote “the definition of insanity is doing the same thing over and over again and expecting different results” is not from Albert Einstein. It has no verified original source, though it appears in Rita Mae Brown’s 1983 novel Sudden Death and in Narcotics Anonymous literature from the same era.
It’s a catchy saying, but it has nothing to do with the actual meaning of insanity in any legal, medical, or clinical context. From a psychology perspective, repeating behaviors isn’t “insanity.” It can be a sign of habit, compulsion, anxiety, OCD, trauma responses, or simply human nature. If you find yourself stuck in patterns that aren’t working, that’s worth exploring with a professional, but it doesn’t mean you’re insane.
When Should You Actually Be Concerned About Your Mental Health?
If you’re reading this article because you’re genuinely worried about yourself or someone you love, here are some signs that it’s time to talk to a mental health professional:
- Persistent changes in mood, thinking, or behavior that last more than a few weeks
- Hearing or seeing things that others don’t
- Beliefs that seem disconnected from reality
- Withdrawing from people and activities you used to enjoy
- Difficulty handling daily responsibilities that you previously managed
- Thoughts of harming yourself or others
These symptoms don’t make you “insane.” They mean your brain needs attention, just like any other part of your body. Conditions like depression, PTSD, bipolar disorder, and ADHD are all highly treatable, especially when caught early.
How MindWell Can Help
At MindWell Psychiatric Services, we don’t label people. We diagnose specific conditions and build treatment plans that work. That starts with a comprehensive psychiatric evaluation to understand what’s actually going on.
From there, treatment might include medication management to address brain chemistry imbalances, genetic testing to find the right medication faster, or a combination of approaches tailored to your situation.
If you’ve been putting off getting help because you’re afraid of being judged or labeled, we get it. That fear is one of the biggest barriers to treatment. At MindWell, you’ll find a judgment-free environment where the goal is understanding, not labeling. Schedule an appointment and let’s figure out what’s going on together.
FAQs
What is the actual definition of insanity?
Insanity is a legal term, not a medical diagnosis. In U.S. law, it refers to a mental state that prevents someone from understanding their actions or knowing right from wrong at the time a crime was committed. It has not been used as a medical term in over 100 years.
Is insanity the same thing as being "crazy"?
Not in any meaningful sense. “Crazy” and “insane” are informal terms that carry a lot of cultural baggage but don’t correspond to any actual medical diagnosis. If you’re concerned about your mental health, focus on specific symptoms rather than labels. A psychiatrist can help identify what’s actually going on.
Did Einstein really say "the definition of insanity is doing the same thing over and over"?
No. There is no evidence Einstein ever said this. The quote most likely originated in Rita Mae Brown’s 1983 novel or in Narcotics Anonymous literature. It has nothing to do with the legal or medical meaning of insanity.
Can insanity be treated?
Since insanity isn’t a medical diagnosis, it can’t be “treated” in the traditional sense. However, the underlying mental health conditions that may lead to a legal finding of insanity (such as psychosis, schizophrenia, or severe bipolar disorder) are treatable with medication, therapy, and ongoing psychiatric care.
What is the insanity defense?
The insanity defense is a legal strategy used in criminal cases. It argues that the defendant was unable to understand their actions or distinguish right from wrong due to a severe mental condition at the time the crime was committed. It’s used in less than 1% of felony cases.
How is insanity different from psychosis?
Psychosis is a medical term describing symptoms like hallucinations and delusions, where a person loses contact with reality. Insanity is a legal term about whether someone understood their actions during a crime. A person experiencing psychosis may or may not meet the legal standard for insanity.
When should I see a psychiatrist?
If you’re experiencing persistent changes in mood, thinking, or behavior that affect your daily life, it’s worth talking to a professional. You don’t need to be in crisis to seek help. A psychiatric evaluation can identify what’s going on and what your options are.
