11Narcissistic personality disorder
Narcissistic personality disorder is a personality disorder in which there is a long-term pattern of abnormal behavior characterized by exaggerated feelings of self-importance, an excessive need for admiration, and a lack of understanding of others' feelings. They cannot accept criticism. They just can't comprehend it.
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 may experience a feeling of tension or arousal and then proceed to eat part of their body, often by simply biting and chewing compulsively. The person may feel pleasure or gratification from this. In one case, a man began by biting his own nails but ended up with such a problem that he severely mutilated his fingers.
14Genital Retraction Syndrome
There is a psychiatric condition called “koro” which is seen mostly in Southeast Asian and Chinese men, where the patient suddenly grasps his penis, fearing that 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 and it consisted of people coming to believe 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 accidental “shattering.”
16Multiple Personality Disorder
People with Dissociative Identity Disorder (Multiple Personality Disorder) can undergo significant changes such as the need for glasses to correct vision, gain/lose an allergy, turn diabetes on and off, and even go from drunk to sober when switching personalities.
17Charles Bonnet Syndrome
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 its sufferers unable to perceive motion. They can still see acutely and recognize objects normally. 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.
The Fregoli delusion is a rare disorder in which a person affected by it holds a delusional belief that various people he/she meets are in fact a single person who changes appearance or is in disguise. The syndrome is usually related to a brain lesion and it is often has a paranoid nature, with the delusional person believing themselves to be persecuted by the person they believe is in disguise.
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.