A delusion is a false belief with three basic characteristics: the person who holds it genuinely and deeply believes it is true; it is demonstrably false; the affected person does not waver in his or her opinion even when presented with solid contradictory evidence. It is markedly different from either a lie or a mistaken belief that changes when corrected. When a person suffers from persistent false beliefs that interfere with his or her daily functioning, he or she may be diagnosed with a delusional disorder.
These disorders can have many different underlying causes: genetic conditions, infections that affect the brain, progressive mental illness, and more. In many cases, doctors are unable to determine exactly why an individual patient has developed his or her symptoms. A certain percentage of these disorders are even caused by brain injuries. Whether the damage is related to a blow to the head, a forceful movement of the head that causes the brain to hit the walls of the skull, or prolonged oxygen deprivation, the consequences can be devastating.
Types of Delusions
A head injury can lead to a wide variety of psychiatric conditions including a wide array of different delusional disorders. The symptoms will depend on the location and the extent of harm done. Although there is still much to learn about the brain, scientists have located certain regions that seem to be connected to different kinds of brain functions. Despite this level of knowledge, the long-term consequences of brain damage can be very difficult to predict, especially the psychological symptoms.
For over a century, psychological researchers have been observing and recording the symptoms of different kinds of delusional disorders. By now, they have identified many different patterns of false beliefs that can plague the victims of these disorders. Some of the more common examples include:
Persecutory This is the most common kind of delusion associated with brain injuries. A persecutory delusion causes its victim to believe that some person or organization is exploiting, mistreating, or planning against him or her. He or she will interpret random or benign occurrences as evidence of some kind of plot or hatred directed at him or her.
Grandiose A grandiose belief is the conviction that the patient has some ability, talent, power, or identity that he or she does not. This can include a conviction that one has supernatural powers, or that one is a celebrity of some kind. Sometimes people with this condition believe that they are the true creator of a famous object or event, but are not receiving fair credit.
Somatic These are beliefs that focus on the body and its functioning. A person with a somatic delusion may believe that parts of his or her body are non-functional or even non-existent, or that they are suffering from some kind of disease or infestation, or that their appearance is somehow unusual or deformed.
Delusions are often mocked or treated lightly in media portrayals of them. However, for affected people and their families, these disorders are highly painful and frightening experiences.