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  • Writer's pictureH. Paul Putman III, MD

Split Personality: Common Misperceptions about Mental Health and Mental Illness

Updated: Sep 23, 2023

In this series we have been reviewing commonly held ideas about mental illness and mental health that, outside of psychiatry, are often not fully or misunderstood. Today we take on a topic that is perhaps of lighter urgency than previous posts, but at the same time probably more widespread and deeply embedded in the public consciousness: “split personality.” Public perception is correct that the term “split personality” is related to the diagnosis of schizophrenia, but what is actually “split” about one’s personality is commonly misunderstood.

The term was first applied by Eugen Bleuler, a Swiss psychiatrist, who in 1908 described the syndrome that would come to be called schizophrenia.[1] As no effective treatments for schizophrenia existed then, Bleuler and others observed the fulminant expression of the disorder throughout the lifespan. He described it, combining the Greek words for “split” – schizo – and “mind” – phrene – to render a new term for what Emil Kraepelin originally called Dementia Praecox, or early dementia (noting the steady decline in cognition that often accompanies the untreated disorder).[2] The shift from split-mind to split-personality, was made by the public.

What Bleuler and other early psychiatrists meant to describe and convey with this new term of split-mind, was not that an affected person’s mind was divided into separate personalities, but that the separate functions of one’s mind, of one personality, were cut-off from proper interaction with each other. In other words, cognition (thought) and affect (emotion or feeling) are usually connected in the psyche. If someone you love dies, you will usually experience sadness. If you receive a desired work promotion, win a big athletic event, or receive a large sum of money, most people will experience at least temporary happiness about the event. Those afflicted with schizophrenia, however, do not experience the usually predicable links between thought and feelings. We observe their thoughts to be “split” from their feelings, as they do not experience the common associations most would expect.

This is not only evident from their descriptions of what they think and how they feel, but from observations: a person with schizophrenia might giggle, or conversely, show no emotion while discussing the death of a beloved parent. While some might attempt to interpret this as denial, anxiety, shock, or some other temporary stress reaction to terrible news, for people who have schizophrenia this is not a defense mechanism, but a permanent inability to associate their thoughts about events with their with feelings about them.

Over a century of research has still failed to provide an adequate understanding of the underlying pathology that produces this syndrome. It has also not yet resulted in treatments more effective than amelioration of “positive” symptoms (ones we wish were not present) such as hallucinations and delusions. Poorly treated “negative” symptoms (highlighting missing elements we wish were present) include deficits in motivation, social cueing, and social closeness.

Like mood disorders, having schizophrenia does increase one’s risk of suicide.[3] The lifetime modal rate of completed suicide for those afflicted is 10%.[4] Clinicians find it difficult to be adequately aware of depressive or suicidal thoughts in these patients, even with direct questioning, due to the mismatch of affect and cognition and the symptom of predicate logic (e.g., “Are you hearing voices? Yes. Did the voices tell you to say that? Yes.)

Since the public coopted the schizophrenia-related term split-mind to mean split-personality, the mislabeling has also led to a misunderstanding about Dissociative Identity Disorder (DID), more commonly known as Multiple Personality Disorder. The mistake has become so ingrained that usually reliable websites commonly misattribute the origin of the term, not even mentioning schizophrenia.

Experts continue to disagree about whether dissociation, coined by Pierre Janet,[5] and a useful component of many defense mechanisms,[6] can occur to such a degree that a person’s mind actually completely divides into discreet personalities that have diminished or no awareness of each other. Granted, many cases of dissociation can be so severe that a person might not recall hours or days of events once returning to the undissociated state, but others often experience the person as the same during the event. It is not helpful for medical providers, therapists, and well-meaning or fascinated others to reinforce dissociation in a patient by encouraging separation into seemingly separate personalities as part of exploration or treatment.[7]

Extreme dissociation has long been described as a mechanism for responding to traumatic experience(s), though other theories stress social and cognitive variables.[8] In fact, patients with schizophrenia also commonly experience dissociation, though not to a degree that they develop new and separate personalities.[9]

So, spilt-personality does not mean multiple personality, nor does it mean schizophrenia. Medically, it doesn’t mean anything. To repeat the common phrase that being of two minds is “schizophrenic” is to mischaracterize science and the experience of these patients. Still, how often do we hear in the media, and even among academicians in other fields, the term “split-personality” used and the word “schizophrenic” used incorrectly?

Does it matter? A compelling argument can always be made that society gains from a broader appreciation of science by the general public, including the social sciences.[10] Beyond that, less than 1% of the world-wide population suffers from schizophrenia. Nevertheless, that is 23.6 million people.[11] And, though members of this population have problems of mind, they are still people and deserve our respect and understanding as much as anyone else. A truer understanding of their experience, limitations, and needs is more likely to lead to compassionate efforts to improve their lives and provide them access to effective medical care.

In fact, there is value in each of us understanding one another’s personalities better, even when our minds are not split.

Learn more about schizophrenia here, here, and here. Learn more about dissociation and dissociative identity disorder here, here, and here.

[1] Bleuler E, Dementia Praecox or the Group of Schizophrenias. Translated by Zinkin J. International Universities Press, New York, 1911/1950. [2] Park S, Thakkar KN: "Splitting of the mind" revisited: recent neuroimaging evidence for functional dysconnection in schizophrenia and its relation to symptoms. Am J Psychiatry. 2010 Apr; 167(4):366-8. doi: 10.1176/appi.ajp.2010.10010089. PMID: 20360323; PMCID: PMC4584400. [3] Sher L, Kahn RS: Suicide in Schizophrenia: An Educational Overview. Medicina (Kaunas). 2019 Jul 10; 55(7):361. doi: 10.3390/medicina55070361. PMID: 31295938; PMCID: PMC6681260. [4] Siris SG: Suicide and schizophrenia. J Psychopharmacol. 2001; 15(2):127-135. doi:10.1177/026988110101500209. [5] Ellenberger HF: The Discovery of the Unconscious: The History and Evolution of Dynamic Psychiatry. New York: Basic Books, 1970. ISBN 978-0-465-01673-0. [6] Counts RM: The concept of dissociation. J Am Acad Psychoanal. 1990; 18(3):460-479. doi:10.1521/jaap.1.1990.18.3.460. [7] Piper A Jr: Multiple personality disorder. Br J Psychiatry. 1994; 164(5):600-612. doi:10.1192/bjp.164.5.600. [8] Lynn SJ, Maxwell R, Merckelbach H, Lilienfeld SO, Kloet DVH, Miskovic V: Dissociation and its disorders: Competing models, future directions, and a way forward. Clin Psychol Rev. 2019; 73:101755. doi:10.1016/j.cpr.2019.101755. [9] Bob P, Mashour GA: Schizophrenia, dissociation, and consciousness. Conscious Cogn. 2011; 20(4):1042-1049. doi:10.1016/j.concog.2011.04.013. [10] Lewis J, Bartlett A, Riesch H, Stephens N: Why we need a Public Understanding of Social Science. Public Underst Sci. 2023 Jul; 32(5):658-672. Doi: 10.1177/09636625221141862. Epub 2023 Jan 12. PMID: 36632845; PMCID: PMC10333961. [11] Solmi M, Seitidis G, Mavridis D, et al: Incidence, prevalence, and global burden of schizophrenia - data, with critical appraisal, from the Global Burden of Disease (GBD) 2019. Mol Psychiatry (2023).

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