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Evolving the Meaning of Hallucinations and Delusions

How does modern psychiatry view hallucinations and delusions?

Key points

  • The understanding of hallucinations and delusions has drastically evolved over the past century.
  • Awais Aftab is a psychiatrist and faculty at Case Western Reserve University.
  • According to Aftab, the idea of delusions being cognitive responses to other dysfunctions has been neglected.
Source: Илья Мельниченко/Unsplash
Source: Илья Мельниченко/Unsplash

The understanding of hallucinations and delusions has evolved and radically shifted in psychiatry over the past century. From lobotomies to antipsychotics, we now have activist groups such as the Hearing Voices Network that seek to integrate and make meaning of these experiences that verge on the religious, spiritual, and somewhat normal range of human experiences in a way that accepts the whole person without pathologizing them.

What are some of these changes? And where is psychiatry going now in response to these mysterious phenomena? This interview with Awais Aftab, a psychiatrist and faculty at Case Western Reserve University, elaborates on the trends.

SM: How have hallucinations and delusions historically been viewed and treated within your area of psychiatry while you've studied and practiced? And has there been a shift in recent years?

AA: Delusions and hallucinations are diagnostically quite nonspecific. While they are associated in the popular imagination with schizophrenia, they occur across a wide range of psychiatric disorders, including mood episodes such as mania and depression, postpartum psychosis, substance-induced psychosis, brief psychotic disorder, delirium, etc.

Furthermore, non-pathological hallucinations are very common experiences in the general population, and even for delusions, there is this gray area of delusion-like beliefs in the form of firmly-held conspiracy theories and non-delusional paranoia that is common in the general population.

Secondly, even in the case of schizophrenia, it is only in the mid- to late-20th century that delusions and hallucinations come to be seen as primary diagnostic features of the conditions—a transition facilitated by the psychiatrist Kurt Schneider who emphasized certain sorts of delusions and hallucinations (“First Rank Symptoms”) as being pathognomonic of schizophrenia.

For the fathers of the concept of schizophrenia—Emil Kraepelin and Eugen Bleuler—delusions and hallucinations were of secondary importance diagnostically, and they gave greater importance to features such as a deteriorating course of illness, cognitive impairment, peculiarities of thought process, and flattened affect.

Finally, for Bleuler, delusions and hallucinations represented adaptive responses of the mind. Bleuler understood schizophrenia as breakdown in the mind’s ability to make stable associations, and thought this was ultimately caused by a metabolic or genetic defect. However, his understanding of psychosis went beyond this. The historian Anne Harrington explains this a lot better than I can:

Bleuler believed that the biological perspective on schizophrenia went only so far. Beyond the primary symptoms caused by defective biology, patients with schizophrenia also suffered from a wide range of secondary symptoms. They heard disembodied voices, experienced thoughts echoing in their head, practiced strange rituals, hewed to delusions, suffered catatonic spells, and more. There was no point, Bleuler said, in trying to find a biological cause for those symptoms, because they were not caused by brains gone wrong. They were instead caused by patients’ use of psychological mechanisms (especially the kinds identified by Freud) to defend themselves against a world that they experienced through brains that didn’t work right.” [Harrington, Anne. Mind Fixers: Psychiatry's Troubled Search for the Biology of Mental Illness (pp. 45-46). W. W. Norton & Company.]

This idea that delusions and hallucinations might be cognitive and psychological functional responses to other dysfunctions was forgotten, or at the very least was neglected, with the rise of symptom-based diagnostic manuals, and the symptoms themselves came to be seen as dysfunctional. It is only recently—especially through predictive processing approaches to psychosis—that we have begun to find our way back to Bleuler’s hypothesis.

SM: How is “meaning” defined for these symptoms, and how can a reinterpretation of positive symptoms help inform or pave way for new methods of diagnosis?

AA: I think “meaning” has come to represent all the different ways in which psychiatric phenomena are not mere deficit and dysfunction, not merely neurobiology gone awry. So thinking of symptoms as having a functional significance is one aspect of it.

This expands our explanatory repertoire. We can be more attuned to the complex interplay of function and dysfunction, of sense-making and its failures, in which symptoms exist. It encourages us to explore the links between psychopathology and pre-existing beliefs, and how they may be shaped by traumatic experience. As Huw Green puts it: “… delusions don’t appear in a vacuum, rather they form in the minds of people with their own individual history of particular experiences and ideas. Delusions come as part of a package, more or less encouraged by the context of our other pre-existing beliefs, and nurtured through our social connections.”

SM: How can reflection of delusions and hallucinations provide meaning in a holistic sense (not just an empirical or scientific sense) by fostering an integrated and accepted livelihood? How do you think it would change the nature of psychiatry practice towards people with psychosis?

AA: The Hearing Voices movement is a powerful example of how we can create a non-stigmatizing social space to explore the meaning voices hold for a particular individual. It is more difficult to do so with delusions, since delusions are typically accompanied by a lack of insight that prevents meaningful engagement and reflection, but once insight has been restored to some degree, many people do wish to understand what those delusional beliefs might have represented.

The intersection of mystical experiences and psychotic phenomena represents another area where the question of meaning comes up. I remember meeting an individual who had undergone a religious experience amidst an otherwise quite destructive manic episode, and the consequences of that spiritual experience outlasted the mania, culminating in a religious conversion. But they struggled to make sense of it all, because their family members and the clinicians couldn’t see past the psychopathology of mania and psychosis.

I think the work of scholars such as Richard Saville-Smith can be quite valuable here. We have to understand that what we consider to be states of psychosis are richer in meaning and significance than is currently conceivable within the medical framework, and we have to look to our colleagues in fields such as anthropology, religious studies, and Mad studies for collaboration and guidance. When is psychosis a pathology? When is it a reflection of human neurocognitive variation? When does it represent our relationship to the divine? Our culture needs to create spaces to explore these questions in a meaningful way.


Harrington, Anne. Mind Fixers: Psychiatry's Troubled Search for the Biology of Mental Illness (pp. 45-46). W. W. Norton & Company.]

Green, Huw. (2020). Deluded, With Reason. Aeon. <…;

Saville-Smith, Richard. (2023). Acute Religious Experiences as a Way of Seeing Madness. Psychiatry at the Margins. <;

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