Rogan: Ennnnh, it's not even THAT so much as... I've always just been suspicious because how do you even PROVE or CATEGORIZE that? Multi in general is just so squishy...
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
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!