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Three things make a post: Magic Tavern, plural studies, and Holmesageddon
I got a shoutout in the “thanks to some of our patrons” section from this episode of Hello From The Magic Tavern! I never listen to the credits, someone else going through the archive pointed it out to me, which is why it’s from July 2023 and I’m only realizing it now. Neat.
(I’m not a regular supporter, I just jump in for a month every so often to download a new batch of episodes. They get so many patrons, I can’t imagine them thanking everyone, but maybe they do? Or maybe I just got lucky with the timing.)
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After some aggressive weeding of my Youtube recommendations, I finally got it to go back to reccing new videos (a) from channels I’m not already watching (b) that are relevant to my interests! (Fingers crossed that this lasts.)
Mini-vent from watching some new-to-me DID Youtubers: there’s a purported statistic of how 1% of the population actually has DID, and it gets repeated by so many people in the community…
And none of them mention what study it’s from. Pretty sure they’re all quoting each other. I finally found a couple real studies with the number! …They cited it as coming from other studies, which cited it from other studies.
Long story short, I would bet money that every single mention of this stat goes back to this one paper: Sar V, Akyuz G, Dogan O, 2007. Prevalence of dissociative disorders among women in the general population. Psychiatry Res. 149, 169–176. 10.1016/j.psychres.2006.01.005
The title already tells you they were only surveying women. The abstract clarifies that they only surveyed women from one specific city in Turkey. And that “1.1% rate of DID” number…seems to be based on the subjects’ results from “filling out the DDIS one time”? (Anyone with time and access to read the full text — if they were actually diagnosed based on something more, please drop a comment to clarify.)
All of this was published in 2007. And I haven’t found any sign of these results being replicated or verified in any other study in the 14 years since.
I don’t think we can call this one a win, folks.
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Mentioned this on Mastodon back around Holmesageddon, keep meaning to document it here:
“Thankfully [group] came to its senses and changed back to the old policy” sounds exactly like someone complaining about AO3 wrangling decisions, right?
It’s a quote from a professional in my library’s cataloging department, talking about the professionals at the United States Library of Congress.
It’s true the OTW doesn’t always get advice from experts. And yeah, there are ways in which the org has noticeably suffered for it. But sometimes I see “if only AO3 hired professional librarians to handle the tagging system, they would all agree on how to categorize things and never make bad decisions”…and, no. Not how it works. Sure wish it was. But nope.
Re: Dammit Erin you nerdsniped us
Okay, so I dug into my old DSM PDFs. The DSM IV has no prevalence given, but the DSM 5 (2013, so later, but nonetheless at least "reputable,") has under DID's "prevalence" the following statement:
"The 12-month prevalence of dissociative identity disorder among adults in a small U.S. community study was 1.5%. The prevalence across genders in that study was 1.6% for males and 1.4% for females." No citation is given, which is very annoying, but that would certainly help account for the statistic's spread; who could doubt the DSM?
Okay, I did a quick trawl of my multi files, and 2005's got parts? by ATW has: "Current research shows that DID may affect 1% of the general population and perhaps as many as 5-20% of people in psychiatric hospitals, many of whom have received other diagnoses." So that predates 2007, though again, no source.
AHA! I KNEW this citation was significantly older, Hocking's 1992 Living With Your Selves has, in its foreword by Colin Ross: "Today, studies indicate that MPD in fact affects about 1% of adults in the general population, and about 5% of general adult psychiatric inpatients. The dissociative disorder as a group appear to be about as common as the anxiety and mood disorders, and a bit less common than substance abuse: about 10% of the general population has had a dissociative disorder at some time in their lives."
Ross doesn't cite a source, but he was a little tin god of multi (and still is, in some circles), so combined with your search above, I suspect that the citation originates with him. I don't have a stockpile of Ross's stuff on me (he gives me the creeps), but seeing how widespread the statistic is quoted in self-help books and stuff, and seeing the difficulty for most folks in accessing academic articles, I would guess it got dropped in one Colin Ross's books that were published in 1992 or earlier. Turns out there is one: Multiple Personality Disorder: Diagnosis, Clinical Features, and Treatment, from 1989.
I pirated a copy online (thanks, Anna's Archive) and find this:
"Everything that can be said about the prevalence of dissociative disorders in North America in the 1980s and early 1990s is therefore guesswork." (89) (Yes, even though this book was in '89, shrug.) "My estimate is that MPD has a point prevalence of somewhere between 1 in 50 and 1 in 10,000 persons in urban North America." He goes on to explain he chose the "1 in 10,000" based on how many cases he'd seen in Winnipeg, where he practices, then explains the "1 in 50" number as part of a thesis paper a student of his did involving 345 DES questionnaires of students at the University of Manitoba. (91) (I would copy/paste the whole thing, but it's over a page long and the ebook OCR puts line breaks after every word, and I'm sorry, that's more work than I'm willing to put in for this.) The citation he gives for this is:
Ryan, L. (1988). Prevalence of dissociative disorders and symptoms in a university population. Unpublished doctoral dissertation. San Francisco: California Institute of Integral Studies.
Obviously something changed between 1989 and 1992 to make him go from "nobody knows" to this 1% statistic. But that's a nice narrow window for you to look through, with one big name firmly attached to it!
Re: Dammit Erin you nerdsniped us
The one that says "may" and "perhaps" is softening it to the point of being meaningless, ugh.
Okay, looks like I ended up with the second edition (1996) of Ross's 1989 book. It doesn't have the exact lines you quoted, but it has follow-ups! A more-developed iteration of the research with the University of Manitoba students:
Ross, C. A., Ryan, L„ Voigt, H., & Edie, L. (1991). High and low dissociators in a college student population. Dissociation, 4, 147-151
"Ross, Ryan, Voigt, and Edie (1991) administered the DES to 345 college students in Winnipeg, then gave a battery of further measures including the DDIS to 22 students scoring under 5 on the DES and 20 scoring above 22.6. The high scorers were selected by starting with the highest DES score in the sample of 345 students, and working downward until 20 subjects had consented to complete the follow-up battery. High and low DES scorers differed at very high levels of significance on all measures: Of the 20 subjects scoring above 22.6 on the DES, 14 (70%) met DDIS criteria for a dissociative disorder including 8 with DID." (109-110)
So there's the 1-in-50 estimate. 8/345 = 2.3%. But the book itself spells out that the DES and the DDIS are both screening tools, not diagnostic tools. This is "2% of subjects should definitely get psychiatric follow-up to explore if they have DID," it's still a step behind "2% of subjects definitely have DID."
Aaaand here's Ross's switch point between 1989 and 1992!
"To date, only one study has attempted to determine the lifetime prevalence of the dissociative disorders in the general population (Ross, 1991a)." (108)
The 1% DID rate is his interpretation of the results of that study...though he goes into a bunch of detail about the limits and caveats. None of which show up later when he's doing pithy quotes for forewords, which is a shame.
I was going to edit this into the post, but I should probably c&p entire passages and make a whole follow-up post at this point, huh?
One last note here, though -- Ross comes up with a distinct category of "severe DID" -- and says, again from the 1991 study, "no such cases were detected in a sample of 502 respondents" (109).
Not totally sure what his criteria are. I infer/hope it's informed by his experience with patients! And along with more studies of the "people who meet the DDIS criteria for recommended DID screening" rate, we could really use some studies big enough to measure the "people who meet the Ross criteria for severe DID" rate.
Re: Dammit Erin you nerdsniped us
So, the reason Ross gives me the creeps (and I avoid citing him when I can, despite his little tin god status) is because he got ran out of Canada for malpractice. I haven't dug into that, though I give a brief summary here, because it's 500 pages of medical malpractice and False Memory Syndrome Foundation bullshit, which is a LOT of shit to wade through that's especially upsetting for me. But he's also been independently sued for malpractice over false memory stuff.
We could've ended up under his care, since he moved his practice to Dallas and our folks went through a "maybe you need a hospital" period while we lived near there. So there's also personal baggage.
EDIT: also, this statistic gets thrown around a LOT in DID lit. As you saw just through me trawling what I had on hand, it was in self-help books, books by therapists, the DSM... we read it all over the place, back in the day, and I think it's just sorta been tacitly swallowed into the knowledge gestalt, even though its source is rarely cited. I just felt kinda weird about it, even before I had any reason to be suspicious of Ross.