Primary vs. Secondary Delusions

Delusions Opens in new window are traditionally divided into two groups, usually referred to as primary and secondary.

Primary delusions are not understandable and are psychologically irreducible, while secondary delusions are understandable in the context of preceding affects or other experiences.

It is probably most meaningful to use the term primary to imply that delusion is not occurring in response to another psychopathological form such as mood disorder Opens in new window.

Secondary delusion is used in the sense that the false belief is understandable in the present circumstances — because of the pervasive mood state or because of the cultural content.

Considering Primary Delusions

Gruhle (1915) considered that a primary delusion was a disturbance of symbolic meaning, not an alteration in sensory perception Opens in new window, apperception or intelligence.

Primary delusions occur in schizophrenia and not in other conditions; they include both delusional perception and delusional intuition (Cutting, 1985). However, delusional intuition, notion or idea is not pathognomonic of schizophrenia, because in any individual case there is too much scope for arguing whether this delusion is indeed primary, that is, ultimately ununderstandable, or secondary in nature.

Secondary delusions occur in many conditions other than schizophrenia and can sometimes be understood in terms of the person’s background culture or emotional state.

Wernicke (1906) formulated the concept of an autochthonous idea, an idea that is ‘native to the soil’, aboriginal, arising without external cause. The trouble with finding supposed autochthonous or primary delusions Opens in new window is that it can be disputed whether they are truly autochthonous.

For this reason, they are not considered of first rank in Schneider’s (1957) classification of symptoms. It is too difficult to decide in many cases whether a delusion is autochthonous. Several writers have claimed that all delusions are understandable if one knows enough about the patient.

The ultimately ununderstandable

Jaspers’ detailed exposition of delusion Opens in new window has been carefully reviewed by Walker (1991). Jaspers’ concepts of the ununderstandable, and of meaningful connections, are relevant here.

If we ask an offender to describe the psychic world in which he lives—his attitudes and how these developed through his childhood until now—we may be able to understand his sexual cruelty, which at first seemed quite incomprehensible:

the behavior becomes meaningful in the context of abuse by his stepfather and surviving as an adolescent in a harsh urban subculture with violence, humiliation and frustration.

However, when we consider the middle-aged schizophrenic spinster who believes that men unlock the door of her flat, anesthetize her and interfere with her sexually, we find an experience that is ultimately not understandable.

We can understand, on obtaining more details of the history, how her disturbance centers on sexual experience, why she should be distrustful of men, her doubts about her femininity and her feelings of social isolation. However, the delusion, her absolute conviction that these things really are happening to her, that they are true, is not understandable.

The best we can do is to try to understand externally, without really being able to feel ourselves into her position (genetic empathy), what she is thinking and how she experiences it. We cannot understand how such a notion could have developed.

This is the core of the primary or autochthonous delusion Opens in new window: it is ultimately ununderstandable.

The patient described above also believed the police were using rays to observe her.

One does not have to try to find which delusion came first, the anesthesia or the observation by rays, to decide which is primary; primary is not dependent on temporal relationships. In that both delusions are not ultimately understandable, they are both primary delusions.

A delusion can still be primary in this, Jaspers’ sense, although it arises on the basis of a memory, an atmosphere or a perception. The protagonist in Gogol’s Diary of a Madman (Gogol, 1972) says,

‘There is a King of Spain. He has been found at last. That king is me. I only discovered this today’.

This sudden and inexplicable belief arose autonomously and unpremeditated. Thereafter, it dictated the protagonist’s every behavior and influenced his view of the world.

How ideas and delusions are initiated

A delusion Opens in new window is a belief, an idea, a thought, a notion or an intuition, and it arises in the same type of setting as any other idea — in the context of a perception, a memory or an atmosphere — or it may be autochthonous, appearing to occur spontaneously.

Ideas are initiated in the following ways:

  • An example of an idea occurring on the basis of a percept: I smell food cooking and then form the idea that I will go and eat.
  • Ideas may follow memory: I remember listening to a string quartet and form the idea of playing a compact disc.
  • Ideas may arise out of an atmosphere or a mood state: I already feel irritable, and when I collect my car from the garage and it makes an unexplained noise I become unreasonably angry and blame the mechanic for not repairing it satisfactorily.
  • An idea may be autochthonous. I visit a ward of the hospital on an afternoon when I never normally go there. Although I accept that all behavior has an explanation for its occurrence, I do not know why on this particular occasion I did this. Theoretical explanations may be given as to where such ideas come from, for example the unconscious, but subjectively they seem to have occurred de novo. Delusions occur in similar settings on the basis of percept, memory, atmosphere or de novo — ‘out of the blue’.

Secondary delusions

Primary delusions differ from secondary delusions in that the former are ultimately not understandable. Secondary delusions are understandable when a detailed psychiatric history and examination are assessed. That is, they are understandable in terms of the patient’s mood state and/or life history.

A manic patent claimed to be Mary, Queen of Scots. She accepted that the queen in question lived and died centuries ago but claimed descent from her and felt fully entitled to say that she was she.

The belief could be understood in terms of her elated and expansive mood and disappeared as her affective state subsided. A depressed patient believed that he had committed the ‘unforgivable sin’.

Discussion and persuasion, even with a person whose religious views he respected, was of no avail in giving him relief. The belief could be seen as an integral part of his depressed mood.

Depressive delusions may remain after treatment has resulted in improvement from retardation Opens in new window, and they account for suicide occasionally occurring in the recovery phase of depression.

A secondary delusion may become understandable when the patient’s social background is known and the doctor knows the beliefs of the subculture from which he comes. It has been suggested that there may be a decline in the prevalence of delusion occurring with depressive illness, but Eagles (1983), studying admissions to hospital in Edinburgh from 1892 to 1982, considered there to be no genuine reduction.

Secondary delusions (delusion-like ideas) can be traced for their origins to the circumstances of that person’s life, to his current mood state, to the beliefs of his peer group and to his personality. They are understandable and often transient.

There is no subjective distinction between a secondary delusion and an overvalued idea Opens in new window, for the distinction between the two can reliably be made only on the evidence given for holding them.

In sum, a delusion Opens in new window, whether primary or secondary in nature, is based on delusional evidence: the reason the patient gives for holding his belief is like the belief itself — false, unacceptable and incorrigible.

    Research data for this literature has been adapted from these following manuals:
  1. Sims' Symptoms in the Mind: An Introduction to Descriptive Psychopathology By Femi Oyebode
  2. Oxford Handbook of Psychiatry By David Semple, Roger Smyth
  3. Crash Course Psychiatry - E-Book By Katie FM Marwick, Steven Birrell