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

Suicide headaches or cluster headaches are described as the most painful condition humans are capable of experiencing. Women who do get them say the pain can be worse than childbirth. Soldiers who have had limbs blown off would rather step on another landmine than have another episode. Medical experts still aren’t sure what causes them and the only treatment known to be effective is LSD and psychedelic mushrooms.

People with narcissistic personality disorder show a long-term pattern of abnormal behavior characterized by exaggerated feelings of self-importance, excessive need for admiration, and a lack of understanding of others' feelings. They cannot comprehend or accept any kind of criticism.

When people are exposed to an experience of great personal significance, particularly viewing art or natural beauty they can come down with rapid heartbeat, dizziness, fainting, confusion and even hallucinations. This psychosomatic disorder is called Stendhal syndrome. This is commonly seen in people visiting Florence after they are overwhelmed by Florentine art.

There exists an impulse-control disorder known as autophagia. Sufferers of this disorder may experience tension or arousal and then proceed to eat a part of their body, often by simply biting and chewing compulsively. They may feel pleasure or gratification from this. In one particular case, a man began by biting his own nails and ended up severely mutilating his fingers.

There is a psychiatric condition called “koro,” otherwise known as Genital Retraction Syndrome which is seen mostly in Southeast Asian and Chinese men. The patient suffering from it suddenly grabs his penis, fearing it will retract into his abdomen, disappear and ultimately cause his death. Scientists consider that it is caused by psychosexual conflicts and cultural beliefs.

An unusual psychiatric disorder known as Glass Delusion swept through Europe during the late medieval period. People suffering from it believed that they were made out of glass, and feared that they might shatter into pieces. King Charles VI of France suffered from glass delusions. He refused to let people touch him and wore reinforced clothing to protect himself from accidentally shattering himself.

People with Dissociative Identity Disorder, otherwise known as Multiple Personality Disorder, can undergo significant changes such as the need for glasses to correct vision, gain or lose an allergy, turn diabetes on and off, and even go from drunk to sober when switching personalities.

Visual hallucinations are usually associated with schizophrenia or drug use, but there is a condition named Charles Bonnet Syndrome, which can cause a healthy person to experience visual hallucinations. It isn’t caused by any mental illness but caused by vision loss. One-third of the people whose eyesight starts deteriorating, experience vivid, cartoonish visual hallucinations. Victims mostly tend to see weird creatures and animals. The reason behind this is that the brain always expects sensory input from the eyes, but when it receives nothing due to vision loss; it creates its own inputs.

Akinetopsia or motion blindness is a neuropsychological disorder that makes sufferers unable to perceive motion. They can still see acutely and recognize objects normally, but to them, everything seems to be frozen in time only to “jump ahead” in time and freeze again. They often view life as a series of photographs or frozen movie reels.

Fregoli delusion is a psychological disorder that causes the person suffering from it to hold a delusional belief that every person he or she meets is in fact a single person who changes appearance or is in disguise. This disorder is usually caused by a brain lesion and it often has a paranoid nature, with the patient suffering from it believing that they are going to be persecuted by the person they believe is in disguise.