The human mind is a real mystery. Although we know how it works and how different areas of the brain affect our motor functions, our emotions and even our personality, there is still much that even the most knowledgeable experts cannot explain about the human psyche.
As more effort is devoted to the study and analysis of the human mind, experts have also come to discover more unexplained psychological phenomena.
Among them are mental illnesses so bizarre that they seem straight out of horror stories or outlandish fairy tales. Luckily, many of the strangest ones are extremely rare, but that doesn’t take away from the fact that the symptoms and mental effects they cause in their victims are absolutely maddening (and often frightening).
Here are ten of the most bizarre and stupefying mental disorders ever diagnosed.
what are the weirdest mental disorders?
Alice in Wonderland Syndrome

The Alice in Wonderland Syndrome (AIWS) (AIWS), also known as Todd syndrome, causes sufferers to experience distortions in their perceptions of time, space or the way their bodies appear in the world around them.
AIWS sufferers perceive things as larger or smaller than they really are, and may even think that parts of their body – such as their hands or feet – are too small or too large in the space they are in. In reality, there is nothing wrong or weird about their physique.
As in the story by the famous author Lewis Caroll, the syndrome is so named because of the strange physical perceptions experienced by the protagonist, Alice, as she passes through the fantastic and strange place that is Wonderland.
There is currently no definite cause for AIWS, but the condition is often associated with migraines, brain tumors and drug use. Children between the ages of five and ten are also susceptible.
Cotard’s syndrome
The cotard’s syndrome is a frightening mental condition that causes sufferers to believe that parts of their body are missing, or that they are dying, dead or even non-existent. Patients suffering from this condition may come to believe that nothing really exists, and may exhibit detrimental symptoms such as refusing to eat or physically hurting themselves.
In one particular case of Cotard’s delirium, a woman was admitted to the hospital after claiming she was dead and smelled like rotten fish. Upon admission, she asked to be put in a morgue so that she could be with other dead people.
Although the cause of this disorder is not fully known, it has been linked to other underlying conditions such as dementia, stroke and multiple sclerosis, among others.
Paris syndrome
Paris syndrome, a mental disorder that is more amusing than bizarre, is defined as a feeling of great disappointment on the part of some individuals who – upon visiting Paris – experience extreme reality shock because the city does not live up to their expectations.
This very novel condition is accompanied by very real symptoms, such as hallucinations, anxiety, dizziness, sweating and vomiting, all of which can be attributed to the major disconnect between what the sufferer had imagined Paris to be and what the city actually is.
This disorder is most prevalent among Japanese tourists who are obsessed with the idea of visiting Paris and experiencing its beautiful culture and sights, but who, upon arrival, are overwhelmed by the language barrier, the difference in formalities and jet lag.
Add to this the broken image of Paris offered by the Japanese media (worn-out sneakers instead of designer shoes everywhere, or fast food joints instead of outdoor street cafes, etc.), and you have an intensely stressed traveler with many disappointments to deal with.
The Stendhal syndrome
Now this is peculiar. Sufferers of Stendhal syndrome experience symptoms such as anxiety, panic attacks and hallucinations when exposed to art. Or more precisely, extremely beautiful art.
Of course, all art is subjective, but Stendhal syndrome has been documented more in people who visit places with a lot of art and architecture, such as museums and galleries. The condition is named after the French writer Marie-Henri Beyle (whose pen name was Stendhal), who documented his feelings of euphoria and anxiety after visiting the Basilica of the Holy Cross in Italy in 1817.
Although several cases of Stendhal syndrome have been reported in recent decades, psychologists have yet to determine whether or not Stendhal syndrome is classified as a legitimate mental condition.
Alien hand syndrome
Alien hand syndrome causes individuals to experience the terrifying sensation that one of their hands has a mind of its own, with often horrifying effects.
Although a fairly rare disorder, sufferers of alien hand syndrome have been known to exhibit behavior in which one of their hands attempts to do something completely outside of the individual’s main line of thinking.
Some people have claimed that their own hands have tried to choke them, scratch them or even tear off their clothes, and experts are still trying to find a way to cure the disorder.
Strange hand syndrome has manifested most often in individuals with Alzheimer’s disease or Creutzfeld-Jakob disease, as well as in those who have had both cerebral hemispheres separated by surgery.
Capgras syndrome
Capgras syndrome (or Capgras delirium) takes paranoia to a whole new level by inflicting on the sufferer the unshakable feeling that a familiar person or place has been replaced by a perfectly identical imposter.
Capgras syndrome, named after Jean Marie Joseph Capgras, the scientist who first identified it, occurs mostly in people suffering from neurodegenerative diseases such as Alzheimer’s and dementia and, to some extent, also in people with schizophrenia or bipolar disorder.
It is often not explained when, how or why a person with Capgras syndrome may begin to feel that loved ones are replaced by impostors, but it is often said that trying to live with and treat a person with this disorder can be an emotionally painful and exhausting experience.
Clinical lycanthropy
In fantasy fiction, lycanthropy is the affliction whereby an individual becomes a werewolf and is able to take on the form of a wolf under certain conditions (such as a full moon).
However, in the real world, clinical lycanthropy is the delusion experienced by someone who believes they have become an animal.
Those diagnosed with clinical lycanthropy believe that they are in the process of transforming into animals, or that they have already become animals. Observations of patients with clinical lycanthropy have revealed that their experiences range from feeling like animals, to simply behaving like animals by growling, howling or crawling, for example.
Clinical lycanthropy has been associated with the altered mental states that accompany psychosis (the mental state involving such things as delusions or hallucinations) and, despite its name, sufferers do not simply think they are turning (or have turned) into wolves. In fact, clinical lycanthropy can include delusions of becoming everything from foxes to frogs, dogs and even birds.
Klüver-Bucy Syndrome
You may have ever felt the urge to stick something randomly in your mouth, such as a pen or paperclip. But that urge pales in comparison to the one felt by those with Klüver-Bucy syndrome.
Klüver-Bucy syndrome, described as an extremely rare neurological brain disorder stemming from damage to the patient’s two temporal lobes, causes sufferers to feel an unusually strong urge to put objects in their mouths, and they also have a tendency to engage in inappropriate sexual behavior.
While this may sound rather amusing, it is probably not so funny to sufferers of the disorder.
Other symptoms include placidity (the state of being extremely calm), memory loss, changes in appetite, as well as hypermetamorphosis (the urge or need to explore everything).
Because the disorder stems from damage to key areas of the brain, Klüver-Bucy syndrome is quite rare, and is usually treated with the use of psychotropics.
Boanthropia
Boanthropia is similar to clinical lycanthropy in that sufferers believe they have become animals. However, boanthropy is specific to individuals who believe they are cows. Yes, cows.
Boanthropia, one of the rarest psychological disorders ever documented, causes sufferers to think and act as if they are cows or oxen, and their physical behavior resembles that of the bovine species.
Patients experiencing Boanthropia have been recorded to walk on all fours, moo, eat grass and even join other cattle in grazing and prowling through green pastures.
The exact cause of this mental disorder remains unknown, and many have thought it has its origins in witchcraft or overly religious beliefs. More realistically, some experts also think it may stem from other existing conditions, such as schizophrenia or bipolar disorder.
As a result, the treatment of this condition remains vague, although experts prefer to resort to classic psychotherapy methods to see if the patient can be “persuaded” to give up the delusion that eating grass and mooing is completely normal.
Apotemnophilia
Imagine having an uncontrollable desire to get rid of certain parts of your body. That is exactly what sufferers of apotemnophilia or body integrity identity disorder (BIID) experience for long periods of time.
More specifically, sufferers of this disorder constantly have the feeling of being “too whole” to the point of feeling that a certain part of their body – possibly an arm, or a toe, or a foot – should be cut off.
Experts have determined that this frightening mental illness is caused by neurological problems, and some patients who had limbs amputated to quench their desires reported experiencing an improved quality of life as they finally felt “complete,” even though they had to live the rest of their lives with certain impairments.
Koro syndrome
Koro syndrome takes genital-related anxiety to a higher level.
It is described as a psychiatric disorder in which individuals experience extreme irrational paranoia that their penises (in the case of men) or their vulvas/nipples (in the case of women) are shrinking inside their bodies and will eventually lead to their death.
This syndrome is more common among males and is more prevalent in Southeast Asia than anywhere else in the world. It has also been classified as an obsessive-compulsive disorder.
Koro syndrome sufferers report that their obsessions with “shrinking genitals” can range from very mild to extreme, and some patients are compelled to measure their private parts several times a day.
Experts have tried to treat Koro syndrome with medications such as antidepressants, as well as behavioral therapy, with varying degrees of success.
While most people may consider themselves fortunate not to suffer from such extreme conditions, that doesn’t take away from the fact that some of these mental illnesses cause patients to experience truly horrible realities even when everything is actually fine.
For anyone who identifies with the aforementioned disorders (or even if they don’t feel that all is well mentally), it’s probably best to seek professional help.
Understand that there is absolutely no shame in receiving psychiatric treatment, and that going for it can greatly improve the quality of life for those suffering from the most common mental disorders, such as ADHD, eating disorders and depression.