Delusional Disorder

Symptoms
A well supported delusion (in that it is skillfully defended) is the ruler and often times the only symptom of disease. Other characteristics appropriate to the delusion can also be present, such as resentment or aggression.

Types
The delusion may manifest itself as any of the following types:

Persecutory type
The individual believes he or she is being threatened or mistreated my others.

Grandiose type
Victims of the disorder believe that they are extraordinarily important people or are possessed of extraordinary power, knowledge or ability.

Jealous type
In this type, delusion centers on the suspected unfaithfulness of a spouse or sexual partner. This delusion is more common than others.

Eroticmatic type
Individuals convince themselves some person of eminence, often a movie star or well-known political figure (often whom they have never met but to whom they have written frequently) is in love with them.

Somatic type
The false belief focuses on a delusional physical abnormality or disorder.

One extremely rare instance of this disease is called folie à deux. It results from a close relationship with someone else who already has a delusional disorder, often under a closed environment. Both persons then share the delusion.

It is important to note the distinguishing factor between this disorder and paranoid schizophrenia is that in this disorder the symptoms of hallucination, incoherence, and loosened association are not present. This disorder occurs in middle-aged to older persons. However it is free from further deterioration or any type of remission. Typical is the person's unwillingness to participate in treatment or associate casually. It is generally believed that this delusional disorder stems not from genetic or physical means, but rather from pathological early life experiences.