One of the extremely rare mental disorders is what is known as 'Triskaidekaphobia'. This disorder, in layman language, is defined as an extreme fear of the number '13'. This number is commonly associated with ill luck in the Western culture, and is associated with 'Friday the 13th' (which has another name to it - friggatriskaidekaphobia).
However, a more pronounced association of this superstition originated from the fact that there were 13 people who attended the Last Supper of Jesus Christ.
Reactive Attachment Disorder
This psychological issue is, although a rare occurrence, a serious concern for the affected person. It is characterized by infants and young children not being able to set up or build a relationship with their parents or caregivers, which can be deemed as healthy.
With time, and without any treatment, this chronic condition causes the affected child to ignore the need to build loving and caring bonds with other people too. This results in the child being neglected and abused, which eventually ends up in affecting his/her growing brain, and impairing the quality of life.
Are you familiar with anyone who tends to get abnormal feelings while attending too much of beautiful works of art, in a small space of time? If so, then your acquaintance may be suffering from Stendhal syndrome. It increases the heartbeat of the affected individual, and causes dizziness, confusion and even hallucinations.
Stockholm syndrome is a mental problem that persists among people who had or have been kidnapped, or taken as hostage. What happens in this case is, the victim somehow develops a sense of attachment, loyalty and care towards the hostage taker or abductor.
And this he/she develops with a complete ignorance of the danger or risk he/she has been placed by the other person. The same disorder is also seen in people who have been victims of rape, domestic violence or child abuse. Somehow, such people voluntarily comply.
Lima syndrome is another rare psychological disorder that is characterized by inducing behavioral traits in a person which are opposite to that characterized by Stockholm syndrome. Here, the abductor or the hostage taker develops a sense of sympathy and attachment towards the victims.
One interesting mental disorder which scientists have come across is associated with a bizarre opinion that patients form in their mind. It causes them to form a firm notion that their acquaintance(s) (usually a family member or spouse) has or have been replaced by a look-alike imposter. It is known as Capgras delusion.
Walking Corpse Syndrome
Taking it down to the 6th in this list of the uncommon psychological disorders, walking corpse syndrome is what we will tell you about.
As the name subtly suggests, people stricken by this neuropsychiatric disorder live by a belief that their internal organs are missing, or their souls have been removed from their body thus, they are dead or are a non-existent entity. According to the statements made by some people, they even believed that their bodies were decaying with an offensive smell.
This rare medical problem is about an obsessive desire to attract sympathy and concern from others. And to fulfill this need, the patient pretends to be suffering from symptoms of illnesses, or worsens an illness he/she already has.
The patient develops a sheer attitude of exaggerating his/her discomfort, and in some cases, may even induce an injury or illness in order to gain utmost attention from others, especially medical personnel. In most cases, the injury or illness that the patient keeps bragging about is usually self-inflicted.
Exploding Head Syndrome
Speaking of a condition that is not only discomforting for the sufferer but is immensely unpleasant to even hear about. It is known by the term 'exploding head syndrome'. It is not what you may literally assume when you hear about it for the first time.
People who are diagnosed by this rare medical disorder, complain against a din that seems to originate from within their head. Although this may occur anytime during the non-sleeping hours, it tends to be common during sleep. The din for some people may be in the form of a powerful artillery explosion, while for some, it may be a roar or a scream.
Alice in Wonderland syndrome (AIWS)
Alice in Wonderland syndrome (AIWS) is called so due to patients' distorted view of living and non-living objects. Their perception for the size of humans, animals or other objects tends to be smaller than what it is in reality. They may also feel that their body parts have altered in their shape or size.
Some people build up a bizarre notion which causes them to believe that a location or a place exists in two or more places at the same instant. Reduplicative paramnesia is what this intriguing disorder is known as.
This mental problem as rare it is, experts believe that acquired brain injury is a major contributing factor in its development. According to them, the right cerebral hemisphere of brain, when damaged, may trigger this disorder, and so when both the frontal lobes incur any injury.
These unusual and bizarre disorders of the mind have captured the attention and interest of many researchers for decades. And over time, with the help of extensive studies and research, experts have also been able to unfold many aspects of these problems. However, they still remain among the most difficult medical problems to understand, manage or to solve.