30 Scary Mental Illnesses You Won’t Wish On Your Worst Enemy

Impostor phenomenon or fraud syndrome is a psychological pattern describing individuals who are marked by an inability to internalize their accomplishments and suffer persistent fear of being exposed as a "fraud". Despite external evidence of their competence, those experiencing this phenomenon remain convinced that they are frauds, and do not deserve all they have achieved.

People with Misophonia are triggered by common sounds such as chewing, loud breathing or even repeated pen-clicking. It isn’t just an annoyance to them, but reactions range from discomfort to sharp anger to physical violence. It is an actual neurological disorder. There's no cure, but if one is diagnosed there are coping mechanisms that can improve one’s quality of life.

People suffering from Puppy Pregnancy Syndrome believe that shortly after being bitten by a dog, puppies are conceived within their abdomen. They believe that they will eventually die, especially men, who think they will give birth to the puppies through their penis. The syndrome is localized to villages in several states of India.

Exploding Head Syndrome is a benign condition in which an individual experiences loud unreal noises like a bomb exploding or a gunshot going off in their head when falling asleep or waking up. There is no known cause and aside from the shock, it is harmless.

Locked-in Syndrome is a condition in which a patient has cognitive awareness, but can’t move any body part or communicate verbally about their cognitive mental state due to complete paralysis of nearly all voluntary muscles in the body, except for vertical eye movements and blinking. A man named Richard Marsh is a rare survivor of locked-in syndrome. During his coma, he watched his wife beg doctors not to take him off of life support, and witnessed his own rough handling by the nighttime staff. Another man named Martin Pistorius woke up from a coma after 2 years but was unable to show any sign of it, and so was trapped in a lifeless state for a further 10 years whilst being fully aware. Another victim of this disease, Jean-Dominique Bauby wrote a book by blinking his left eyelid for 10 months and died 10 days after the book released.

According to a 2010 report in the journal Current Biology, a woman known only as SM is literally fearless due to a rare genetic condition known as Urbach-Wiethe disease that hardened her amygdala, part of the brain responsible for fear response. Researchers exposed her to snakes, spiders, an amusement park haunted house and horror films, none of which scared her. Researchers said that these finding could help in progress for the treatment of post-traumatic stress disorders.

There is a mental illness named “Münchausen Syndrome by Proxy” where a caregiver deliberately induces physical or mental problems in those who are in their care. This is typically done to gain attention and sympathy for themselves. Approximately 1% of asthma cases in children are faked by their parents. The worst case where this was noticed was of Marybeth Tinning, who is suspected of have killed all 9 of her children in a span of 14 years.

Morgellons disease is a delusional infestation. People affected by it become delusional and see things crawling beneath their skin and see bugs coming out of their body. They then start scratching themselves, forming sores, in order to purge their bodies of fibers that they believe is implanted in them from a certain organism. This “disease” has been reported all across the world, and even a Congressional study was conducted.

Sleeping beauty syndrome or Kleine-Levin syndrome is a rare sleep disorder that causes the patients to experience periods of excessive sleep episodes, which can last anywhere from 20 hours a day to a couple of days to even weeks. About 80 percent of patients are teenagers when they first experience KLS. These episodes of lengthy sleep may be proceeded by flu-like symptoms and, when they're awake, people with this syndrome may exhibit various odd behaviors, including eating excessively, hallucinating or acting childishly.

Jerusalem Syndrome is an intense religious psychosis that is triggered when a person who seems previously balanced and devoid of any signs of psychopathology becomes psychotic after arriving in Jerusalem. It is not endemic to one single religion or denomination but has affected Jews, Christians, and Muslims alike. An affected person may believe himself to be the coming of the Messiah or the second coming of Christ. This psychosis resolves to full recovery after leaving Jerusalem.