Dissociative Identity Disorder (DID) is the name given to the old Multiple Personality Disorder (MPD). It means that the person is suffering from distinctive multiple personalities, and the host personality has amnesia of the other personalities activities.  DID is the most controversial disorder within current mental health literature, and the reason is simple; they changed the name to include the word "Dissociative" which has a much broader meaning than MPD. You will either be for it, or against it; I will state that less than 25% of the mental health industry is for it. 
**** Scheduled For Update to Latest Criterion and Rewriting ****
Diagnostic criteria for 300.14 Dissociative Identity Disorder
A. The presence of two or more distinct identities or personality states (each with its own relatively enduring pattern of perceiving, relating to, and thinking about the environment and self).
B. At least two of these identities or personality states recurrently take control of the person's behaviour.
C. Inability to recall important personal information that is too extensive to be explained by ordinary forgetfulness.
D. The disturbance is not due to the direct physiological effects of a substance (e.g., blackouts or chaotic behaviour during Alcohol Intoxication) or a general medical condition (e.g., complex partial seizures). Note: In children, the symptoms are not attributable to imaginary playmates or other fantasy play.
Self Proclaimed Experts Symptom Analysis
Based on studies, the following symptoms have been ascertained by a select few who have classified themselves as experts,  as being the real symptoms of DID; Amnesia, conversion, voices, depersonalisation, trances, self-alteration, de-realisation, awareness of the presence of alters, identity confusion, flashbacks, auditory & visual hallucination, schneiderian first-rank symptoms (schizophrenia).
Mental Health Industry Perspective
It seems very clear from reading research on this subject that the mental health industry is quite divided on DID. The problem though for those fore it, is that they're a very small minority, less than 25% of the mental health industry as a statistic.
Its actually not that the majority don't believe multiple personalities can exist, that's just not it at all. In-fact prior statistics have demonstrated the belief that the industry believes of its existence, though is extremely rare. Its definition of words that is killing diagnosis by those broadening terms beyond their defined meanings, or watering down for a better term. 
Some try and blame the Diagnostic and Statistical Manual of Mental Disorders (DSM), American Psychiatric Association, for this, but its not the DSM at fault, and in-fact they got the disorder correct in the first instance, being it was merely a renaming from MPD to DID. MPD has always been classified as extremely rare. The problem stems from a select group who allocate themselves as experts, self-determined the word "dissociative" to its broadest possible spectrum, went into private practice and charge a whole lot of money for very few patients.  Physicians have been creating their own diagnostic criteria for an existing diagnosis, similar to what occurred with Complex Posttraumatic Stress Disorder (CPTSD), though the difference is that they recognised the difference between PTSD and CPTSD, so they created a new category for it based on the new data and presented it. What self proclaimed DID experts are trying to do, is fit new / expanding symptoms and their personal interpretations of words, into an existing diagnosis, and keep the name for the fame and popularity purpose that DID brings.
Here's the thing, if the select few didn't really care about the fame or popularity as they often claim, then why aren't they using the allocated diagnosis that is already available for their newly defined criteria, being, Dissociative Disorder Not Otherwise Specified (DDNOS)?
In most sources referenced [1 - 5] you will find references to childhood abuse, PTSD, and that to have DID in the first instance, you would have had to endure childhood abuse at an abnormally traumatic level, which is what causes DID itself. Some of these self proclaimed experts have attempted to use arguments that possession and such fits the model, and these are not a requirement of childhood abuse. So lets just round it out, that 99.99% of DID patients would have endured childhood abuse of an abnormally traumatic level, in that the brain has been incorrectly programmed so that the child has used these dissociative states from childhood through to adulthood as a coping mechanism.
One study has even attempted to relate a decrease in the Amygdala and Hippocampal region as being associated to DID, when in fact the same study references PTSD in the patients. PTSD is already medically proven to decrease both these areas, so I am unsure to the validity of this argument and attempting to associate it with DID exclusively. 
Here is the real kicker to the entire argument, fore or against. It seems the majority of mental health physicians agree that those with DID have multiple disorders, including Axis I & Axis II, being personality disorders; defined by the DSM IV. It is also clear, that a majority agree that Borderline Personality Disorder (BPD) and other personality based disorders are predominant within those with CPTSD. 
Agreed Disorders Defined
Expanding the above statement, those who endure complex trauma are often associated to also suffer one or multiple from: Depersonalisation Disorder, Dissociative Amnesia, Paranoid, Schitzoid, Anti-Social, Borderline, Avoidant, Dependent or Obsessive Compulsive Disorder/s. These all over-lap one another with symptoms. 
PTSD, let alone CPTSD, and BPD, all encompass known dissociation, and even states (personalities). The moment you read a study or article on DID, and it mentions childhood trauma or PTSD, then its finding are useless as the patient has known dissociative states, not unique to DID, hence why they fit better with current diagnosis vs. DID, and having to force the patient within it.
Self Inflicting DID
Further scepticism with DID comes due to the known behaviours associated with the diagnostic assessment itself, followed by specific symptoms of patient flamboyance about obtaining / having the diagnosis. It is very common that those with complex trauma lie. It comes part and parcel with the associated personality disorders often attached due to the childhood abuse and protection mechanisms the patient uses to protect themselves. They will make-up stories and / or manipulate, they will act, or fit themselves within guidelines for attention purposes. These are all well known, clinically proven aspects associated with childhood trauma. Its not the patients fault though, it all stops with the therapist.
If a patient says, "I feel like I have an alter ego, I feel like its not me", then the therapist responds, "would you say you have a different personality?" That is the same moment the conversation was intentionally led towards a conclusion of another personality existing, therefor; DID could not be diagnosed as the leading question placed the presence of another personality within the persons brain. The same comes from someone who says, "I have these different personalities, I know them as Sadie, Lucy, Gloria, etc". The patient just disclosed that they are fully aware of personalities, which goes against the amnesia aspects of the DID diagnosis and the host.
Part and parcel of CPTSD is that under the worst cases, an abused child will carry with them and manifest their pretend friends, or dissociative states, to adulthood through alters. This is perfectly normal with CPTSD and dissociative states, though it doesn't make them a multiple personality that function independently of the host.
A Country In Ruins
The USA economy has been in trouble for some years now, and around the same time as the financial woes began, some American physicians began claiming an epidemic of DID; though seems to be limited to, wait for it, North America only. Private practitioners fore DID seem to have a 73% stake in diagnosing it, then treating it, followed by combined outpatient clinics, treating the next majority at 17%. That's 90% of the DID fore's being within private practice in the USA. Coincidence or not? No other country seems to have really changed in terms of DID diagnosis (MPD), being usually around the 0.01% - 0.1% range, all hit by the same global financial crisis as the USA.
The average private practitioner within the USA who diagnoses and treats a DID patient will obtain approximately $25,000 per annum from treating that one patient, with an average 5 year treatment period. Funnily enough, the same names tend to appear as private practitioners in fore studies, all averaging 5 or more DID patients at the one time. Coincidence again?
It seems directly in-line with USA physicians diagnosing patients with PTSD for being cheated upon by their partner, and all sorts of nonsense based trauma. Still coincidence, or not? Starting to see a pattern once you begin looking?
DSM V Outcome
From review of the current state of the DSM V for all dissociative disorders, at present they are rewriting the entire category, possibly removing all present dissociative disorders and replacing with a generic dissociative disorder diagnosis, where the clinician fits the symptoms the patient presents uniquely. 2013 will derive whether this outcome is reality upon its release.
- Brand, Classen, Lanins, Loewenstein, et al., 2009, A Naturalistic Study of Dissociative Identity Disorder and Dissociative Disorder Not Otherwise Specified Patients Treated by Community Clinicians
- Dell, 2006, A New Model of Dissociative Identity Disorder
- Gharaibeh, 2009, Dissociate Identity Disorder: Time to Remove it from DSM-V
- Vermetten, Schmahl, Lindner, Loewenstein, Bremnar, 2006, Hippocampal and Amygdalar Volumes in Dissociative Identity Disorder
- Gleaves, 1996, The Socio-cognitive Model of Dissociative Identity Disorder: A Reexamination of the Evidence
- American Psychiatric Association, 2000, Diagnostic and Statistical Manual of Mental Disorders (DSM) IV-TR
Dissociative Identity Disorder
Diagnostic criterion and applicable data for the diagnosis of Dissociative Identity Disorder (DID).
Users found this page by searching for:
dissociative identity disorder statistics,
dissociative identity disorder forums,
ptsd and multiple personality disorder,
- statistics dissociative identity disorder,
- dissociative identity disorder statistics in the us,
- DSM IV Dissociative Disorder rating 1-5,
- multiple personality disorder statistics in usa,
- 2013 statistics on identity disorders in the us,
- ptsd blackouts and cheating,
- dissociative identity disorder facts,
- evidence against dissociative identity disorder,
- current literature on dissaciative Identity disorder,
- dessosiative identity disorder for against,
- ptsd two personalities,
- dissociative identity disorder spouse support