15 Most Horrifying Mental Disorders of All Time (2023)

Imagine suffering from a mental illness that causes you to believe your significant other is an imposter set on harming you, or which convinces you that books are for eating, or worse yet, that you have somehow become the walking dead. What if you felt like yourself one day and the next day someone else was in the mirror? Scary, right?

Unfortunately for some people, these scary feelings are an every day reality. While only a small percentage of people are forced to live with the mental disorders described above, the fact remains that 450 million people worldwide suffer from mental illness. In the United States alone, one in four families is affected. Experts believe that mental illness is an actual epidemic and the United States needs far more mental health services in order to help the people in need.

While some mental disorders, such as depression, can occur naturally, others are the result of brain trauma or other injuries. We may all recognize the names of other more common mental disorders such as bipolar disorder, obsessive compulsive disorder, post traumatic stress disorder, anxiety disorder, or autism spectrum disorder.While all of these mental illnesses and many others that we did not list can be scary for those suffering, there are a few rare psychotic disorders that are especially terrifying.Below, we’ve described what we think you’ll agree are the 15 scariest mental disorders of all time.

Alice in Wonderland Syndrome

Alice in Wonderland may be pure fantasy, but one of Alice’s more bizarre experiences shares its characteristics with a scary mental disorder. Known also as Todd Syndrome, Alice in Wonderland Syndrome causes one’s surroundings to appear distorted. Just as Alice grows too tall for the house, those suffering from Alice in Wonderland Syndrome will hear sounds either quieter or louder than they actually are, see objects larger or smaller than reality, and even lose sense of accurate velocity or textures. This terrifying mental disorder, which has been described as an LSD trip without the euphoria, even perverts one’s own body image. Fortunately, Alice in Wonderland Syndrome is extremely rare, and in most cases affects those in their 20s who have a brain tumor or history of substance abuse. A mental illness like this one will make you want to keep your mental health a top priority!

Alien Hand Syndrome

Though it’s often been used in terrifying plot twists, Alien Hand Syndrome is hardly limited to the fictional world. Those with this scary, but fortunately rare, mental disorder experience a complete loss of control of a hand or limb. The uncontrollable limb often seems to take on a mind and will of its own, and sufferers have reported their “alien” limb attempting to choke either themselves or others, ripping clothing, or scratching to the point of blood. Alien Hand Syndrome most often appears in patients with Alzheimer’s Disease, Creutzfeldt-Jakob Disease, as a result of brain surgery during which the brain’s two hemispheres have been separated, or mental illnesses. Unfortunately, no cure exists for Alien Hand Syndrome, and those affected by it are often left to keep their hands constantly occupied or use their other hand to control the alien hand.

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Known also as Body Integrity Disorder and Amputee Identity Disorder, Apotemnophilia is a neurological disorder characterized by the overwhelming desire to amputate or damage healthy parts of the body. Though not much is known about this strangely terrifying mental illness, is is believed to be associated with damage to the right parietal lobe of the brain. Because the vast majority of surgeons will not amputate healthy limbs upon request, some sufferers of Apotemnophilia feel forced to amputate on their own — a dangerous scenario. Of those who have had a limb removed by a doctor, most are reportedly happy with their decision even after the fact. This is one of the most interesting mental disorders that mental healthprofessionals are clearly still trying to understand and treat.


This mental illness is likely one you have never heard of. But yes, it is real! Those who suffer from the very rare — but very scary — mental disorder Boanthropy believe they are cows, often going as far as to behave as such. Sometimes those with Boanthropy are even found in fields with cows, walking on all fours and chewing grass as if they were a true member of the herd. Those with Boanthropy do not seem to realize what they’re doing when they act like a cow, leading researchers to believe that this odd mental disorder is brought on by dreams or even hypnotism. Interestingly, it is believed that Boanthropy is even referred to in the Bible, as King Nebuchadnezzar is described as being “driven from men and did eat grass as oxen.”

Capgras Delusion

Capras Delusion, named after Joseph Capgras, a French psychiatrist who was fascinated by the illusion of doubles, is a debilitating mental disorder in which one believes that the people around them have been replaced by imposters. This is one of the most fascinating anxiety disordersto date.People suffering from this severe mental disorder believe that these imposters are usually thought to be planning to harm the sufferer. In one case, a 74-year old woman with Capgras Delusion began to believe that her husband had been replaced with an identical looking imposter who was out to hurt her. Capgras Delusion is relatively rare, and is most often seen after trauma to the brain, or in those who have been diagnosed with dementia, schizophrenia, epilepsy, or an anxiety disorder.

Clinical Lycanthropy

Like those with Boanthropy (described above), those who suffer from Clinical Lycanthropy also believe themselves to be able to turn into animals — in this case, wolves and werewolves, though occasionally other types of animals are included. Along with the belief that they can become wolves, people with Clinical Lycanthropy also begin to act like an animal, and are often found living or hiding in forests and other wooded areas.

Clinical Lycanthropy is a very rare psychotic disorderand is typically brought on by other mental health conditions. Experts believe it is a psychotic episode caused by schizophrenia, bipolar disorder, or a depressive disorder.

(Video) 15 Scariest Mental Disorders of All Time |Psychology Facts & Tips

Cotard Delusion

There’s a healthy interest in The Walking Dead and other elements of the current zombie trend, and then there’s Cotard Delusion. This scary mental disorder causes the sufferer to believe that they are the walking dead (literally) or a ghost, and that their body is decaying and/or they’ve lost all blood and internal organs. The feeling of having a rotting body is usually part of the delusion, and it shouldn’t come as a surprise that many sufferers of Cotard Delusion experience severe depression or manic depression. In some cases, the delusion causes sufferers to starve themselves to death. This terrifying disorder was first described in 1880 by neurologist Jules Cotard, though fortunately, Cotard’s Delusion has proven extremely rare. The most well-known case of Cotard Delusion actually occurred in Haiti, where a man was absolutely convinced he had died of AIDS and was in Hell. BBC Radio’s “A History of Delusions” has an interesting episode on “Walking Corpse Delusion” that you can list to here.

Diogenes Syndrome

Diogenes Syndrome is more commonly referred to as simply “hoarding,” and is one of the most misunderstood mental disorders. This mental illness has gained popularity because of popular television shows on those who suffer from it being treated by mental health professionals and is actually more common than you may think. Named after the Greek philosopher Diogenes of Sinope (who was, ironically, a minimalist), this syndrome is usually characterized by the overwhelming desire to collect seemingly random items, to which an emotional attachment is then formed.

In addition to uncontrollable hoarding, those with Diogenes Syndrome often exhibit extreme self neglect, apathy towards themselves or others, social withdrawal, and no shame for their habits. It is very common among the elderly, those with dementia, those with a mental health history, and people who have at some point in their lives been abandoned or who have lacked a stable home environment.

Dissociative Identity Disorder

Dissociative Identity Disorder (DID), known formerly as Multiple Personality Disorder, is a terrifying mental illness that is included in myriad movies and television shows, but is extremely misunderstood. Very generally, the less than .1% of people who suffer from DID often have 2-3 different identities (and sometimes more). The American Psychiatric Association explains that victims of dissociate disorders suffer from problems with their memory, identity, emotion, perception, behavior, and sense of self.

Sufferers routinely cycle through their personalities, and can remain as one identity for hours or for years. They can switch identities at any time and without warning, and it’s nearly impossible to convince someone with DID that they have it. For these reasons, those with Dissociative Identity Disorder are unable to live normal lives, and therefore usually live in psychiatric institutions.

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Factitious Disorder

Most people cringe at the first sniffle indicating a potential cold or illness, but not those with Factitious Disorder. This scary mental disorder is characterized by an obsession with being sick. In fact, most people with Factitious Disorder intentionally make themselves ill in order to receive treatment (this makes it different than hypochondria). Sometimes, sufferers will simply pretend to be ill, a ruse which includes elaborate stories, long lists of symptoms, and jumping from hospital to hospital. Such an obsession with sickness often stems from past trauma or serious mental illness. It affects less than .5% of the general population, and while there’s no cure, it is often able to be limited via psychotherapy.

Kluver-Bucy Syndrome

Imagine craving the taste of a book or wanting to have sex with a car. That’s reality for those affected by Kluver-Bucy Syndrome, a scary mental disorder characterized by memory loss, the desire to eat inedible objects, and sexual attraction to inanimate objects such as automobiles. Not surprisingly, those with Kluver-Bucy Syndrome often have trouble recognizing objects or people that should be familiar. This terrifying mental disorder is difficult to diagnose, and seems to be the result of severe injury to the brain’s temporal lobe. Unfortunately, there is not a cure for Kluver-Bucy Syndrome and sufferers are often affected for the rest of their lives. They may severely struggle in their daily life in terms of their personal relationships, career, and more.

Obsessive Compulsive Disorder

Though it’s widely heard of and often mocked, Obsessive Compulsive Disorder (OCD) is fully understood by very few. OCD manifests itself in a variety of ways, but is most often characterized by immense fear, anxiety, and recurring thoughts of worry. It’s only through the repetition of tasks, including the well-known obsession with cleanliness, that sufferers of OCD are able to find relief from such overwhelming feelings. To make matters worse, those with OCD are often entirely aware that their fears are irrational, though that realization alone brings about a new cycle of anxiety. Obsessive Compulsive Disorder affects approximately 1% of the population, and though scientists are unsure of the exact cause, it is thought that chemicals in the brain are a contributing factor.

Paris Syndrome

Paris Syndrome is an extremely odd temporary mental disorder that causes one to become completely overwhelmed while visiting the city of Paris. Interestingly, it seems to be most common among Japanese travelers. Of the approximately 6 million Japanese visitors to Paris each year, 1-2 dozen experience the overwhelming anxiety, depersonalization, derealization, persecutory ideas, hallucinations, and acute delusions that characterize Paris Syndrome. Doctors can only guess as to what causes this rare affliction. Because most people who experience Paris Syndrome do not have a history of mental illness, the leading thought it that this scary neurological disorder is triggered by the language barrier, physical and mental exhaustion, and the reality of Paris as compared to the idealized version.

Reduplicative Amnesia

Reduplicative Amnesia is very similar to Capgras Syndrome, but instead of believing that people are duplicates, those with Reduplicative Amnesia believe that a location has been duplicated. This belief manifests in many ways, but always includes the sufferer being convinced that a location exists in two places at once. The term “Reduplicative Amnesia” was first used in 1903 by neurologist Arnold Pick, and described a patient with Alzheimer’s. Today, it is most often seen in patients with tumors, dementia, brain injury, or other psychiatric disorders.

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Stendahl Syndrome

Stendahl Syndrome is a psychosomatic illness that is, fortunately, seemingly only temporary. The syndrome occurs when the sufferer is exposed to a large amount of art in one place, or in other environments characterized by extreme beauty. Those who experience this odd, yet scary mental disorder report sudden rapid heartbeat, overwhelming anxiety, confusion, dizziness, and even hallucinations. Stendahl Syndrome is named after the 19th century French author who described in detail his experience after an 1817 trip to Florence. Those who suffer from Stendahl Syndromemay not have a history of mental illness or mental disorders. However, it may more commonly present itself in those with anxiety disorders or other mood disorders.

Mental health is one of the most controversial and interesting topics in our world and has been since the beginning of psychology.Learning about mental illnesses and mental disorders helps us understand mental health and the struggles of those around us. Mental health services can teach us a lot and help those suffering to find the help they need but unfortunately for some, there is no cure. While these 15 mental disorders are terrifying and feel unimaginable, they are a reality for many victims and have them suffering from constant thoughts that can be so difficult to manage.

Related Resources:

  • 10 Most Deranged Serial Killers of All Time
  • 10 Things to Know About the Psychology of Cults
  • What is Borderline Personality Disorder?
  • What is Bipolar Disorder?
  • What is Dissociative Identity Disorder?


Which is the most severe mental illness? ›

By all accounts, serious mental illnesses include “schizophrenia-spectrum disorders,” “severe bipolar disorder,” and “severe major depression” as specifically and narrowly defined in DSM. People with those disorders comprise the bulk of those with serious mental illness.

What is the strangest mental disorder? ›

Also known as Todd syndrome, Alice in Wonderland syndrome (AIWS) is a neurological condition in which one's perception of their body image, time, or space is distorted. Those experiencing AIWS may have hallucinations, sensory distortion, and an altered sense of velocity.

What are the top 10 mental disorders? ›

This article examines ten of the most common mental illnesses among American adults.
  • Depression. ...
  • Dissociative Disorders. ...
  • Attention Deficit Hyperactivity Disorder (ADHD) ...
  • Post-Traumatic Stress Disorder. ...
  • Schizophrenia. ...
  • Obsessive-Compulsive Disorder. ...
  • Eating Disorders. ...
  • Addiction & Substance Abuse.
7 Jan 2022

What are the 12 major psychological disorders? ›

This page lists some of the more common mental health issues and mental illnesses.
  • Anxiety disorders. ...
  • Behavioural and emotional disorders in children. ...
  • Bipolar affective disorder. ...
  • Depression. ...
  • Dissociation and dissociative disorders. ...
  • Eating disorders. ...
  • Obsessive compulsive disorder. ...
  • Paranoia.

What mental illness can cause death? ›

The sudden death rate was 0.36% for those under voluntary care and 0.7% for those under compulsory care. The most common primary diagnoses were alcohol or other drug abuse (29%); depression (25%); psychotic disorders (18%); BPAD (9%) and personality disorder (5%).

Which mental illness carries the highest death rate? ›

Anorexia nervosa (AN) is a common eating disorder with the highest mortality rate of all psychiatric diseases.

What Mental Illness does Joker have? ›

Antisocial personality disorder

At the same time, as I have stated, Arthur has the symptoms of psychopathy. Although psychopathy is not among the ten official personality disorders listed in DSM-5, it is well recognised as a variant of antisocial personality disorder (301.7, according to DSM-5).

What is one of the hardest mental illnesses to live with? ›

But in the shadows are a cluster of conditions that continue to face deep discrimination: schizophrenia, psychosis, bipolar disorder, and BPD. BPD in particular is one of the lesser-known mental illnesses, but all the same it is one of the hardest to reckon with.

What are the 5 major mental illnesses? ›

Five major mental illnesses — autism, attention deficit-hyperactivity disorder, bipolar disorder, major depressive disorder and schizophrenia — appear to share some common genetic risk factors, according to an examination of genetic data from more than 60,000 people worldwide (The Lancet, online Feb. 28).

What are the top 2 mental illnesses? ›

Right now, nearly 10 million Americans are living with a serious mental disorder. The most common are anxiety disorders major depression and bipolar disorder.

What are the big 3 mental disorders? ›

Of those, the three most common diagnoses are anxiety disorders, depression and post-traumatic stress disorder (PTSD). These three conditions make up around 30 percent of all diagnoses of mental illness in America.

What are 2 common mental disorders? ›

Some common ones include: Anxiety disorders, including panic disorder, obsessive-compulsive disorder, and phobias. Depression, bipolar disorder, and other mood disorders. Eating disorders.

What are the deadliest disorders? ›

If you think depression, schizophrenia, or bipolar disorder are the mental illnesses most commonly linked to an early death, you're wrong. Eating disorders—including anorexia nervosa, bulimia, and binge eating— are the most lethal mental health conditions, according to research in Current Psychiatry Reports.

What is the rarest psychological disorder? ›

Factitious disorder tends to affect less than 0.5% of the population. Also known as 'imposter syndrome' or Capgras Delusion. People with this mental health condition believe that someone in their life that plays a significant role what been replaced with an imposter.

What are the top 4 mental illnesses? ›

Below are the five most common mental health disorders in America and their related symptoms:
  • Anxiety Disorders. The most common category of mental health disorders in America impacts approximately 40 million adults 18 and older. ...
  • Mood Disorders. ...
  • Psychotic Disorders. ...
  • Dementia. ...
  • Eating disorders.
30 Jan 2020

What is the biggest cause of mental illness? ›

For example, the following factors could potentially result in a period of poor mental health: childhood abuse, trauma, or neglect. social isolation or loneliness. experiencing discrimination and stigma, including racism.

Can mental stress lead to death? ›

Stress is unlikely to be fatal for most people, but prolonged exposure to stress can lead to mental and physical health problems, including death in severe cases. But dying from stress is unusual and is likely the result of a heart attack or another cardiovascular issue.

What is the life expectancy of someone with mental illness? ›

According to the World Health Organization, people with severe mental health disorders have a 10–25-year reduction in life expectancy. Schizophrenia mortality rates are between 2 and 2.5 times those in the general population, while individuals with depression have a 1.8 times higher risk of premature mortality.

What are the 7 main mental disorders? ›

What Are the 7 types of Mental Disorders?
  • Anxiety Disorders.
  • Mood Disorders.
  • Psychotic Disorders.
  • Eating Disorders.
  • Personality Disorders.
  • Dementia.
  • Autism.
6 Apr 2021

Do BPD people get manic? ›

People with BPD do not generally have manic episodes. They vary from feeling loving and secure in their relationship to depressed, angry, or lonely. However, both people with BPD and people with bipolar disorder can be at risk for self-harm and impulsive behaviors.

How many people have died from mental illnesses? ›

We estimate that 14.3% of deaths worldwide, or approximately 8 million deaths each year, are attributable to mental disorders.

What disorder does Harley Quinn have? ›

Personality Disorder, specifically, Histrionic Personality Disorder plays a key part in Harley Quinn's life. People with Histrionic Personality Disorder are “pervasive and excessive emotionally and display attention-seeking behavior” (Bornstein 1998).

What mental illness do serial killers have? ›

As a psychoanalyst, Stone's specialty is personality disorders so it is not surprising that most of the mass murderers in his study were diagnosed with antisocial, psychopathic, narcissistic or paranoid personality disorder.

Is Batman a sociopath? ›

Batman displays a barrage of psychopathic tendencies, but his genuine need to save the citizens of Gotham keeps him from having an outright case of antisocial personality disorder (ASPD), the diagnosable condition most associated with sociopathy.

What is the most painful mental disorder to live with? ›

Borderline personality disorder (BPD) has long been believed to be a disorder that produces the most intense emotional pain and distress in those who have this condition. Studies have shown that borderline patients experience chronic and significant emotional suffering and mental agony.

How many total mental illnesses are there? ›

Mental Illness Defined

There are more than 200 classified forms of mental illness. Some of the more common disorders are: clinical depression, bipolar disorder, dementia, schizophrenia and anxiety disorders.

At what age does 50% of all lifetime mental ill health begin? ›

Half of all lifetime mental illness begins by age 14, and 75% by age 24.

Can a person have multiple mental disorders? ›

Yes, according to the National Institute of Mental Health. The organization found, in a 12-month period, almost 50 percent of adults in the United States with any psychiatric disorder had two or more disorders. Psychology Today estimated that 7.9 million of U.S. adults live with more than one mental disorder.

What are the 6 major mental illnesses? ›

Some of the main groups of mental disorders are:
  • mood disorders (such as depression or bipolar disorder)
  • anxiety disorders.
  • personality disorders.
  • psychotic disorders (such as schizophrenia)
  • eating disorders.
  • trauma-related disorders (such as post-traumatic stress disorder)
  • substance abuse disorders.

What is the most common mental disorder in childhood? ›

Facts about mental disorders in U.S. children. ADHD, anxiety problems, behavior problems, and depression are the most commonly diagnosed mental disorders in children.

Which disease has no cure? ›

cancer. dementia, including Alzheimer's disease. advanced lung, heart, kidney and liver disease. stroke and other neurological diseases, including motor neurone disease and multiple sclerosis.

What is the biggest disorder in the world? ›

Mental health statistics worldwide

Anxiety affects 284 million people in the world. Depression affects 264 million people. Alcohol use disorder affects 107 million people. Drug use disorder affects 71 million people.

What is the hardest disorder to deal with? ›

But antisocial personality disorder is one of the most difficult types of personality disorders to treat. A person with antisocial personality disorder may also be reluctant to seek treatment and may only start therapy when ordered to do so by a court.

What are the hardest psychological disorders to treat? ›

Personality disorders are some of the most difficult disorders to treat in psychiatry. This is mainly because people with personality disorders don't think their behavior is problematic, so they don't often seek treatment.

What's the most common disorder? ›

Anxiety Disorders: Anxiety disorders are the most common mental health condition in the US and can include OCD, panic attacks and phobias. It is estimated that 40 million adults have an anxiety disorder.

Is schizophrenia the most severe mental illness? ›

Schizophrenia is a chronic, severe mental disorder that affects the way a person thinks, acts, expresses emotions, perceives reality, and relates to others. Though schizophrenia isn't as common as other major mental illnesses, it can be the most chronic and disabling.

What are the top 3 most common mental illnesses? ›

The most common are anxiety disorders major depression and bipolar disorder.

What are severe cases of mental illness? ›

Serious mental illness (SMI) is defined as a mental, behavioral, or emotional disorder resulting in serious functional impairment, which substantially interferes with or limits one or more major life activities.

What are the 4 types of mental illness? ›

mood disorders (such as depression or bipolar disorder) anxiety disorders. personality disorders. psychotic disorders (such as schizophrenia)

What movie is based on schizophrenia? ›

Perhaps the best-known movie about schizophrenia, “A Beautiful Mind” is a powerful account of the life of mathematician and Nobel Prize winner John Nash (Russell Crowe).

What do all schizophrenics suffer from? ›

Schizophrenia usually involves delusions (false beliefs), hallucinations (seeing or hearing things that don't exist), unusual physical behavior, and disorganized thinking and speech. It is common for people with schizophrenia to have paranoid thoughts or hear voices.

Who suffers from schizophrenia most often? ›

Schizophrenia is typically diagnosed in the late teens years to early thirties, and tends to emerge earlier in males (late adolescence – early twenties) than females (early twenties – early thirties). More subtle changes in cognition and social relationships may precede the actual diagnosis, often by years.

What is the most treatable mental illness? ›

Depression is among the most treatable of mental disorders. Between 80% and 90% percent of people with depression eventually respond well to treatment.

How many mental disorders can a person have? ›

Technically, according to DSM-5*, a person can receive more than one personality disorder diagnosis. People who are diagnosed with a personality disorder most often qualify for more than one diagnosis. A person with a severe personality disorder might meet the criteria for four, five or even more disorders!

What are the 7 major mental disorders? ›

What Are the 7 types of Mental Disorders?
  • Anxiety Disorders.
  • Mood Disorders.
  • Psychotic Disorders.
  • Eating Disorders.
  • Personality Disorders.
  • Dementia.
  • Autism.
6 Apr 2021


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