How did schizophrenia and multiple personality disorder get mixed in the public imagination?

For some reason schizophrenia and multiple personality disorder are considered one and the same in the public consciousness, even though they are totally unrelated disorders from a psychiatric point of view (one being a fairly common, very serious psychiatric disorder, the other being rare to the point of possibly not existing). There are number examples of this in popular culture (e.g. from today’s news: Ben Carson saying ‘American Muslims must be “schizophrenic” for trying to follow their religion while living in America.’).

How did this happen? AFAIK even when the possibility of widespread multiple personality disorder was part of the psychiatric mainstream, it was never considered a symptom of schizophrenia. But somehow popular culture has conflated the two conditions.

The term ‘schizophrenia’ litearlly means ‘split mind’.

That’s correct and schizophrenic is an actual descriptive word as well besides the mental illness definition (e.g., Our local government keeps passing schizophrenic recycling laws that contradict each other.) I agree that unfortunate and inaccurate nomenclature is a major cause of the common misunderstanding.

“(in general use) a mentality or approach characterized by inconsistent or contradictory elements.”

It also doesn’t help that their are several rather distinct forms of schizophrenia but the symptom most people think of first is hearing voices. Those are not separate personalities in the true sense either but the distinction is rather subtle and difficult to understand for most lay people. I didn’t really understand it myself until I sat down with someone who was experiencing acute schizophrenic symptoms and asked him to describe it to me in real time. The most basic summary is that the voices are like a radio or TV playing in the background that you can’t turn off. However, they typically experience it as an outside annoyance rather than a separate personality because their sense of self doesn’t change.

That said, I don’t think most people believe that schizophrenia and multiple personality disorder are the same thing. I have heard plenty of people make that mistake but most somewhat educated people understand that they are different even if they can’t articulate how very precisely.

See also, schizoid personality disorder, schizotypal personality disorder, schizoaffective disorder. The first two may or may not have links to schizophrenia while the third is related; none are related to MPD. And the multiple personalities are usually encapsulated (don’t interact), whereas schizophrenia that involves hallucinations are consciously present.

By the way, the correct term for multiple personality is dissociative identity disorder and it was never mainstream. Not only is it very, very rare but some doubt that it’s a real diagnosis. Whereas schizophrenia has tons of genetic links already established, even if we still don’t know a lot about it or the causes.

Well, perhaps “never” is the wrong word. The guy who first invented the term (in 1908) may have lumped it in. From the wiki article:

Bolding mine.

Schreiber, Flora Rheta; Sybil; Edward Regnery Co., Chicago; 1973.

This is the book that brought the notion of “multiple personalities” into the public discourse. I guess anymore it’s called disassociative personality disorder, AC + AD = A (C + D).

“Sybil,” both the book and the movie.

That brought MPD to the public awareness. But what associated it with schizophrenia?

MPD was in the public awareness well before Sybil due to the move Three Faces of Eve.

The Three Faces of Eve (1957)

If we’re talking media incorrect usage, one cannot ignore Quadrophenia, where the title is used to mean that the main character has 4 different personalities (each represented by one of each of the four band members.

“Schizophrenic? I’m bleedin’ quadrophenic!”

I have multiple personality disorder.

Me too!

Not Jeckyll and Hyde?

But you’re good people!

They don’t now, but I remember in the 70s and early 80s when they were used interchangeably. There has been a lot of effective debunking, and now most people understand the difference.

Personally, I think it’s an iatrogenic disorder most of the time, but those people really manifest personalities, and hav black-out episodes.

However, I have a theory, which is just my lay theory, and IANA psychiatrist, neurologist, or psychologist, but I have dealt with lots of disabled people, and there is a type of seizure that was only recently known to exist, called a “focal seizure,” where a person can remain conscious and function with a portion of their brain, while another part is experiencing a seizure. The person is not usually capable of making long-term memories during a focal seizure, and experiences them as black-outs, even though other people might insist they were conscious and talking.

I knew one guy who had focal seizures that lasted as long as six hours (extremely unusual), and during them, needed to be looked out for, but was still capable of using the bathroom, dressing himself, and getting food that did not require preparation. It looked like he had reverted to a child-like state, and I think a therapist who was both predisposed to see DID, and unaware of focal seizures might have thought he had switched to another personality.

Anyway, given that DID patients always seem to have child personalities, and iatrogenic psychiatric problems are very real, I wonder if focal seizures and over-eager therapists explain most cases of DID. Or, at least most early cases. I would not be shocked to learn that many people post-Sybil were faking. And I feel sorry for them. They were probably abused, and neglected emotionally as children, and wanted a nurturing relationship with a therapist like the one in the movie.

I’ve never gotten the impression that significant numbers of people are confused on this score. The terminology can get careless, but I think most people understand that schizophrenia and supposedly having multiple different personalities are quite different.

Actually, Carson didn’t quite say that - he was referring to Muslims who adhere to Sharia law while supposedly supporting the American philosophy of separation of church and state.*

*I haven’t heard Carson call some fundamentalist Christians “schizophrenic” for having a somewhat similar problem.

How old are you? It used to be common. I remember thinking that schizophrenia meant “multiple personalities” when I was around the age of 12, but ignorance was fought in the 1990s, and no one makes this mistake anymore; lay people generally used “schizophrenia” to mean MPD/DID up until about 1980, though-- or maybe 1985. Right up until good medications for actual schizophrenia came along, and people needed to know what psychotic disorders were, because for some people they were becoming conditions they could function with, if properly medicated, and thousands of people were being de-institutionalized, while many more were not being institutionalized in the first place.

When you never knew someone with schizophrenia, and were unlikely to meet someone with the condition, it was less important for you to be clear on the terminology, but now that you might be working with, or living next do to someone who was schizophrenic, you needed to know what the word meant.

Hollywood and their ability to spread misinformation…

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