Delusional disorders are a relatively common mental illness that frequently goes unreported by patients. The severity of the condition is a wide range, with some patients experiencing only mild effects of the delusional disorders and others that are so severe that they extremely limit how a person is able to function in the world. Delusional disorders are split into six specific groupings: erotomanic, jealousy, grandiose, somatic, persecution, and mixed types. All of these subtypes are quite similar in nature, but they are represented in society in different ways. To define delusional thinking, the criteria developed by Karl Jasper in 1917 is commonly used. His definition stated that the specific delusion had to be believed completely and that no argument or proof of its falsity would sway a patient’s mind. Also, the delusion must be false in nature or impossible.

The persecution type of delusional disorder is the most common variety of the condition. A person with this problem will have a paranoid delusional definition that they are being unjustly pursued or persecuted by a specific force. The paranoid delusional definition does not require that the patient be able to name the source of the persecution and many cases involve only the feeling of being persecuted. However, in other cases, the patient may feel as though they are being followed by governmental organizations or that family members are trying to harm them. The paranoid delusional definition is also involved in the jealousy type of delusions. In this subtype, a patient feels as though his sexual partner is committing sexual acts with another person. In some cases, the patient will assemble false evidence to support the theory and confront the partner. This evidence is often wildly inaccurate and only serves the delusional person’s purpose.

One example of the somatic subtype delusional disorder is known as delusional parasitosis. In this specific example, a patient feels that they are infected with parasites. They will often claim that they can feel the parasites under the skin. As the delusion can be very strong, the problem will often be referred to a dermatologist or entomologist for study as the person is sure of the problem. The erotomania subtype occurs when a patient is convinced that a person is in love with the patient. Often, this love will be thought to have been communicated through body language, including special looks or signals, or through supernatural abilities, such as telepathy. In most cases, the patient finds that it is someone famous that is trying to communicate with them. The grandiose subtype occurs when a person has true delusions of grandeur, believing that they are somehow more powerful than ordinary people. Mixed delusions are when a person experiences more than one type of delusion at the same time.

To define delusional thinking in a specific patient, a local psychiatrist should be consulted to make a thorough examination before diagnosing the problem. The symptoms expressed by a delusional disorder can also be part of a much more serious problem, such as bipolar disorder or schizophrenia. The correct treatment practice of curing delusional disorders will depend on a proper diagnosis of the problem.