What Are the Main Types of Delusions?
Delusions are characteristic of mental or neurological disorders. Thus, they help diagnose psychotic disorders. Psychiatrist and philosopher Karl Jaspers was the first to define three main criteria to identify the types of delusions in his book General Psychopathology (1913).
These criteria are the following:
- Certainty. Holding the belief with absolute conviction.
- Incorrigibility. The belief can’t be changed by convincing counterarguments.
- The falsity or impossibility of the belief.
As you can guess, applying the concept of falsity (or truthfulness) can be troublesome. Thus, according to Karl Jaspers, there are two main types of delusions: by how the patient holds the belief and by its content.
Types of Delusions by the Patient’s Beliefs
From a formal point of view, there are two types of delusions: primary or truthful and secondary.
Primary delusions, or autochthonous, are autonomous, original, and incomprehensible from a psychological point of view. They appear suddenly, the patient has a complete conviction of it, and there are no other mental alterations to explain it.
Secondary delusions arise from a previous abnormal experience. It’s a delusional idea that manifests as an attempt to explain strange, senseless experiences. That’s why they’re psychologically understandable.
Thus, the difference between primary and secondary delusions is whether the delusion is understandable or not. This distinction also includes the attempt to explain where the delusion itself comes from. Also, saying that secondary delusions are psychologically understandable means that they’re the consequence of the patient’s attempt to explain an abnormal experience.
Jaspers’ Four Types of Primary Delusions:
- Delusional intuition. Phenomenologically indistinguishable from any idea that manifests abruptly. The content of these delusional ideas tends to be self-referential and, in general, is highly important to the patient.
- Delusional perception. Consists of the delusional interpretation of a normal perception.
- Delusional atmosphere. The subjective belief that the world has slightly changed for the worse. It usually comes with mood swings because the patient feels uncomfortable or perplex.
- Delusional memory. It’s the delusional reconstruction of a real memory.
Types of Delusion by Content
From psychoanalytic theories, experts have emphasized the symbolic importance of the delusion’s content. Some authors even claim that the content is related to personal fears, with the influence of life experiences and cultural factors as well.
However, others say that delusions are simply shallow speeches. Berrios claims that their content is nothing more than a random fragment of information trapped in the moment where the delusion is visible to others.
Despite this last opinion, delusions have been studied from the perspective of judgment and belief. And from this point of view, content is clearly important to assess personal or cultural influences.
While the structure of delusions barely changes in different cultures, the cultural framework the patient belongs to seems to affect their content. In fact, one of the most researched arguments about delusions is their classification by content.
Most Common Delusions by Content
- Delusional jealousy. The delusional conviction that their sexual partner is cheating. It usually starts abruptly and the proof to this belief will depend on a word or a gesture by the partner. In fact, the delusional person will try to search irrefutable evidence (going through the partner’s belongings, asking many questions, etc.).
- Delusions of grandeur. Its content involves an exaggerated view of one’s own importance, power, knowledge, or personal identity. It can also be religious, physical, or of another kind.
- Delusion of poverty. Having the idea that they’ll lose or have already lost all their material belongings.
- Delusion of people being able to read one’s mind.
- Cotard or nihilistic delusion. The idea that the world has ended and that nothing exists.
Other Common Delusions
- Delusion of control. For example, thinking that feelings, impulses, thoughts, or actions are controlled or imposed by an external force. Typical delusions include thoughts being stolen, aligning with other people’s thoughts or telepathy.
- Erotomania. The patient thinks that someone else is madly in love with them. Curiously enough, it affects women more frequently than men, and often the person has the conviction that someone famous loves them (a movie star, a politician, etc.)
- Somatic delusion. It’s the conviction of having a physical flaw or a medical condition. It can be hard to distinguish this disorder from hypochondria or body dysmorphic disorder. But what sets it apart from the other conditions is how intense the belief is. They can’t consider the possibility that the flaw or the condition doesn’t exist.
- Delusion of reference. This is the delusion that insignificant events or people have a particular meaning or purpose in the patient’s life. If the delusional idea includes a persecutor, then it’s a persecutory delusion.