Schizophrenia is classified as a psychotic disorder, which means the inability to tell the difference between what is real or imagined. Two types of psychotic symptoms characteristic of this serious psychiatric disorder are hallucinations and delusions.
What are delusions?
A delusion is a false belief which a person holds with a strong amount of conviction. The belief isn’t typical of his/her culture or religion, and he/she adheres to the erroneous belief despite evidence and proof which totally contradict it.
Types of delusions
Persecutory
In schizophrenia, as well as other psychotic disorders such as delusional disorder, delusions may have a variety of themes. The most common type of delusion associated with schizophrenia involves persecutory delusions. The schizophrenic believes that he/she is being followed or is under surveillance, or that he/she is being made fun of, tricked, or treated very unfairly by others. When schizophrenics experience this type of delusion, they may feel very frightened or paranoid. As a result, they will often do things to protect themselves from the persecutor(s).
Delusions of reference
This is when the person believes, for example, that things written in a newspaper or stated in a newscast, passages found in a book, or the words in a song are about him/her.
Grandiose delusions
Grandiose delusions involve the belief that he/she has exceptional power, talent or worth, or is someone famous. He/she may believe he/she is God or some other type of deity.
Erotomanic delusions
This type of delusion involves the belief that a particular person, usually a celebrity or someone especially important, is romantically or sexually involved with or in love with him/her.
Somatic delusions
This involves the belief that he/she has a medical condition or other physical problem or flaw.
Thought insertion, withdrawal, control, or broadcasting
These types of delusions (always considered bizarre in nature) occur when the person believes that someone, often aliens, are putting (inserting) thoughts into his/her mind, removing or controlling his/her thoughts, or broadcasting them so that others can hear them, usually against his/her will.
Bizarre versus non-bizarre delusions
Usually in schizophrenia the delusions are completely implausible or bizarre in nature, although at times they may not be. An example of a bizarre delusion would be a person who believes aliens have removed his/her brain and replaced it with an alien brain. A non-bizarre delusion would be something which could happen in reality, such as being under observation by the FBI.