Editing Dissociative identity disorder (section)

===Early references===
In the 19th century, ''dédoublement,'' or "double consciousness", the historical precursor to DID, was frequently described as a state of [[sleepwalking]], with scholars hypothesizing that the patients were switching between a normal consciousness and a "somnambulistic state".<ref name = Kloet2012>{{cite journal | last1 = Van Der Kloet | first1 = D. | last2 = Merckelbach | first2 = H. | last3 = Giesbrecht | first3 = T. | last4 = Lynn | first4 = S. J. | title = Fragmented Sleep, Fragmented Mind: The Role of Sleep in Dissociative Symptoms | journal = Perspectives on Psychological Science | volume = 7 | issue = 2 | pages = 159–175 | year = 2012 | pmid =  26168441| doi = 10.1177/1745691612437597 | s2cid = 8919592 }}</ref>

An intense interest in [[Spiritualism (beliefs)|spiritualism]], [[parapsychology]] and [[hypnosis]] continued throughout the 19th and early 20th centuries,<ref name="pmid7794202">{{cite journal |vauthors=Atchison M, McFarlane AC | title = A review of dissociation and dissociative disorders | journal = The Australian and New Zealand Journal of Psychiatry | volume = 28 | issue = 4 | pages = 591–9 | year = 1994 | pmid = 7794202 | doi = 10.3109/00048679409080782 }}</ref> running in parallel with [[John Locke]]'s views that there was an [[association of ideas]] requiring the coexistence of feelings with awareness of the feelings.<ref name="pmid12094818">{{cite journal | author = Rieber RW | title = The duality of the brain and the multiplicity of minds: can you have it both ways? | journal = History of Psychiatry | volume = 13 | issue = 49 Pt 1 | pages = 3–17 | year = 2002 | pmid = 12094818 | doi = 10.1177/0957154X0201304901 | s2cid = 22746038 }}</ref> [[Hypnosis]], which was pioneered in the late 18th century by [[Franz Mesmer]] and [[Armand-Marie-Jacques de Chastenet, Marques of Puységur|Armand-Marie Jacques de Chastenet, Marques de Puységur]], challenged Locke's association of ideas. Hypnotists reported what they thought were second personalities emerging during hypnosis and wondered how two minds could coexist.<ref name="pmid7794202" />

[[File:Plaque Pierre Janet, 54 rue de Varenne, Paris 7.jpg|thumb|The plaque on the former house of [[Pierre Janet|Pierre Marie Félix Janet]] (1859–1947), the philosopher and psychologist who first alleged a connection between events in the subject's past and present mental health, also coining the words "dissociation" and "subconscious"]]

In the 19th century, there were a number of reported cases of multiple personalities which Rieber<ref name="pmid12094818"/> estimated would be close to 100. [[Epilepsy]] was seen as a factor in some cases,<ref name="pmid12094818" /> and discussion of this connection continues into the present era.<ref name="pmid6427406">{{cite journal |vauthors=Cocores JA, Bender AL, McBride E | title = Multiple personality, seizure disorder, and the electroencephalogram | journal = The Journal of Nervous and Mental Disease | volume = 172 | issue = 7 | pages = 436–438 | year = 1984 | pmid = 6427406 | doi = 10.1097/00005053-198407000-00011 }}</ref><ref name="pmid2725878">{{cite journal |vauthors=Devinsky O, Putnam F, Grafman J, Bromfield E, Theodore WH | title = Dissociative states and epilepsy | journal = Neurology | volume = 39 | issue = 6 | pages = 835–840 | year = 1989 | pmid = 2725878 | doi = 10.1212/wnl.39.6.835 | s2cid = 31641885 }}</ref>

By the late 19th century, there was a general acceptance that emotionally traumatic experiences could cause long-term disorders which might display a variety of symptoms.<ref name="Borch-Jacobsen M 2000">{{cite journal | author = Borch-Jacobsen M | title = How to predict the past: from trauma to repression | journal = History of Psychiatry | volume = 11 | issue = 41 Pt 1 | pages = 15–35 | year = 2000 | pmid = 11624606 | doi = 10.1177/0957154X0001104102 | s2cid = 32666101 }}</ref> These [[conversion disorder]]s were found to occur in even the most resilient individuals, but with profound effect in someone with emotional instability like [[Louis Vivet]] (1863–?), who had a traumatic experience as a 17-year-old when he encountered a viper. Vivet was the subject of countless medical papers and became the most studied case of dissociation in the 19th century.

Between 1880 and 1920, various international medical conferences devoted time to sessions on dissociation.<ref name="putnam">{{cite book | last = Putnam | first = Frank W. | title = Diagnosis and Treatment of Multiple Personality Disorder | url = https://archive.org/details/diagnosistreatme00putnrich | url-access = registration | publisher = The Guilford Press | year = 1989 | location =New York | page = [https://archive.org/details/diagnosistreatme00putnrich/page/351 351] | isbn = 978-0-89862-177-8}}</ref> It was in this climate that [[Jean-Martin Charcot]] introduced his ideas of the impact of nervous shocks as a cause for a variety of neurological conditions. One of Charcot's students, [[Pierre Janet]], took these ideas and went on to develop his own theories of dissociation.<ref name="pmid2686473">{{cite journal |vauthors=van der Kolk BA, van der Hart O | title = Pierre Janet and the breakdown of adaptation in psychological trauma | journal = Am J Psychiatry | volume = 146 | issue = 12 | pages = 1530–40 | date = December 1989 | pmid = 2686473 | doi =  10.1176/ajp.146.12.1530| citeseerx = 10.1.1.455.2523 }}</ref> One of the first individuals diagnosed with multiple personalities to be scientifically studied was Clara Norton Fowler, under the [[pseudonym]] [[Christine Beauchamp (pseudonym)|Christine Beauchamp]]; American [[neurology|neurologist]] [[Morton Prince]] studied Fowler between 1898 and 1904, describing her [[case study]] in his 1906 [[monograph]], ''Dissociation of a Personality''.<ref name="pmid2686473"/><ref>{{cite book|url=https://archive.org/details/dissociationofpe00prinuoft|page=[https://archive.org/details/dissociationofpe00prinuoft/page/1 1]|quote=Louis Vivé.|title=The Dissociation of a Personality|publisher=Longmans, Green|last1=Prince|first1=Morton|year=1920}}</ref>