Oh, dear Lord... (so to speak.) Do y'all really want to know the answer to this? Because I have done extensive research in this area, and I've also worked with clients who have both PTSD and dissociative disorders. I don't agree with some clinicians whose ideas were formed in an earlier era and who are not willing to look at all the new research, and who are so convinced that they "don't have any clients who are really dissociative". But I don't generally get into debates in this forum and I don't really like to do it. However, there is no legitimate "controversy" here. The existence and prevalence of the dissociative disorders is accepted by the American Psychiatric Association and the American Medical Association. Take out your copy of the
Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision,, and turn to page 519. Read about dissociative amnesia, dissociative fugue, dissociative identity disorder, depersonalization disorder, and dissociative disorder not otherwise specified.
Here's some information about the Dissociative Experiences Scale, which is a self-adminstered
screening instrument-- not the same as a "test" for a dissociative disorder. Please understand that the DES is an instrument used to screen clients for two much more detailed clinical assessments, the Dissociative Disorders Interview Scale and the Structured Clinical Interview for DSM-IV Dissociative Disorders.
The Dissociative Experiences Scale is a brief self-assessment instrument which asks questions related to the 5 symptom clusters, assessing experiences of depersonalization, derealization, amnesia, identity confusion, and identity alteration (Gleaves & May, 2001; Simeon, 2006).
Validity of the DES:
Psychometrically sound: mean alpha, or internal reliability, of .93, and convergent validity (between the DES and other measures of dissociation) of .67 (van Ijzendoorn & Schuengle, 1996)
Strong test-retest reliability among dissociative disorder patients, correlations of .93 over 2, 4, and 8 week intervals (Dubester & Braun, 1995; Frischholz et al, 1990).
More DES validity:
By comparison: Structured Clinical Interview for DSM-III-R kappa for 21 separate diagnoses averaged .61 (Williams et al, 1992)
The DES distinguished between dissociative disorder patients and students with 98.9% accuracy and a kappa of .93.
The DES distinguished between dissociative disorder patients and eating-disordered patients with 100% accuracy and a kappa of 1. (Gleaves & May, 2001).
The DES has been shown to have cross-cultural validity in the United States, Canada, Netherlands, Turkey, Puerto Rico, Norway, Sweden, Germany, China, and India; versions currently being developed in Japan and Australia. It has been found reliable among children, adolescents, adults, and older adults. (Gleaves &May, 2001; Kluft, 2007; Nilsson & Svedin, 2006; Xiao et al, 2006. ) It has been found to screen accurately for dissociative disorders in groups of males, females, Caucasians, African-Americans, Asian-Americans, and Hispanics (Foote et al, 2001; Gleaves & May, 2001).
Here's more about the prevalence of the dissociative disorders:
Dissociative disorder diagnoses, if correctly made, would represent up to 10% of all psychiatric populations, but are diagnosed in less than 1% of all clients (Coons,1998).
Most common comorbid diagnosis by far is major depression, around 50% (Coons, 1998; Foote et al,2006; Gleaves & May, 2001).
*
I have some detailed information about the incidence and prevalence of dissociative disorders in patients who have already been admitted to outpatient or inpatient psychiatric settings with a co-occuring psychiatric disorder. This is the context in which the Turkish study was mentioned above, and that is why the incidence was so high.
Dissociative disorders usually remain undiagnosed until an average of seven years into therapeutic treatment, by which time the average client has received six to seven separate psychiatric diagnoses (van der Haart, 2005)
Here's some information about the DDIS, which
is used to actually test more reliably for a dissociative disorder, as the DES is
not:
Dissociative Disorders Interview Schedule is a 131-item structured interview used to assess diagnoses of somatization disorder, major depression, borderline personality disorder, alcohol and drug abuse, and the five DSM-IV dissociative disorders. It also enquires about a range of other experiences such as trauma history and features associated with dissociative disorders, such Schneiderian symptoms (first-rank symptoms of schizophrenia). It has a kappa of .68 (.78 for DID), with sensitivity(false positives) of less than 1% and specificity (false negatives) of 0%. (Ross et al, 1989).
Here's more about the validity of the Structured Clinical Interview for Dissociative Disorders; the SCI really is the gold standard for diagnosis of all serious mental illnesses and mental disorders:
The SCID-D was developed by Steinberg, Rounsaville, and Cicchetti (1990) to assess the presence and severity of symptoms in the 5 areas. Diagnostic reliability assessed for presence/absence of a dissociative disorder, type of disorder, and severity of specific symptoms, with a kappa of .92. (ibid). Boon and Draijer (1991) found a kappa of .98 on presence/absence of dissociative disorder and 1.0 on diagnosis of dissociative identity disorder. The same reliability and validity figures have been found for the latest revised version, the SCID-D-R (Steinberg, 2000).
References
Adolescent Dissociative Experiences Scale-II (A-DES) (Armstrong,
Carlson, & Putnam, 2003)., Retrieved 4/22/09 from
http://www.seinstitute.com/pdf_files/a-des.pdf.
Akyuz, G., Dogan, O., Sar, V., Yargic, L., & Tutkun, H. (1999). Frequency of dissociative identity disorder in the general population in Turkey. Comprehensive Psychiatry, 40(2), 151-159.
American Psychiatric Association. (2000). Diagnostic and statistical manual of mental Disorders (Revised 4th ed.). Washington, DC: Author.
Boon, S., & Draijer, N. (1991). Diagnosing dissociative disorders in the Netherlands: A pilot study with the structured clinical interview for DSM-III-R dissociative disorders. American Journal of Psychiatry, 148, 458-462.
Coons, P. (1998). The dissociative disorders: Rarely considered and underdiagnosed. Psychiatric Clinics of North America. 21(3), 637-648.
Durham, R., Chambers, J., Power, K., Sharp, D., MacDonald, R., Major, K, et al.. (2005) Long-term outcome of cognitive behaviour therapy clinical trials in central Scotland. Health Technology Assessment, 9(42), 1-174.
Foote, B., Smolin, Y., Kaplan, M., Legan, M., & Lipschitz, D. (2006). Prevalence of dissociative disorders in psychiatric outpatients. American Journal of Psychiatry, 163, 623-629.
Friedl, M., & Draijer, N. (2000). Dissociative disorders in Dutch psychiatric inpatients. American Journal of Psychiatry, 157, 1012-1013.
Gleaves, D., & May, M.(2001). An examination of the diagnostic validity of dissociative identity disorder. Clinical Psychology Review, 21(4), 577-608.
Haddock, D.(2001). The dissociative identity disorder sourcebook. McGraw-Hill: New York.
Horen, S., Leichner, P., & Lawson, J.(1995). Prevalence of dissociative symptoms and disorders in an adult psychiatric inpatient population in Canada. Canadian Journal of Psychiatry, 40(4), 185-191.
Kluft, R. (2007). The older female patient with a complex chronic dissociative disorder. Journal of Women and Aging, 19(2), 199-137.
Mulder, R., Beautrais, A., Joyce, P., & Fergusson, D. (1998). Relationship between dissociation, childhood sexual abuse, childhood physical abuse, and mental illness in a general population sample. American Journal of Psychiatry, 155, 806-811.
Nilson, D., & Svedin, C.(2006). Evaluation of the Swedish version of Dissociation Questionnarire (DIS-Q), DIS-Q-Sweden, among adolescents. Journal of Trauma and Dissociation, 7(3), 65-89.
Ross, C. (1991). Epidemiology of multiple personality disorder and dissociation. Psychiatric Clinics of North America, 14, 503-517.
Ross, C. (2007). Borderline personality disorder and dissociation. Journal of Trauma and Dissociation, 8(1), 71-80.
Sar, V., Koyuncu, A., Ozturk, E., Yargic, L., Kundakci, T., Yazici, A., et al. (2007). Dissociative disorders in the psychiatric emergency ward. General Hospital Psychiatry, 29, 45-50.
Sierra, M., & Berrios, G. (1999). The Cambridge Depersonalization Scale: A new instrument for the measurement of depersonalization. Psychiatry Research, 93, 53-64.
Simeon, D., Guralnik, O., Schmediler, J., Sirof, B., & Knutelska, M. (2001). The role of childhood interpersonal trauma in derpersonalization disorder. American Journal of Psychiatry, 158(7), 1027-1033.
Simeon, D., Knutelska, M., Nelson, D., Guralnik O., (2003). Feeling
Unreal: A Depersonalization Disorder Update of 117 Cases., Dept. of Psychiatry: Mount Sinai School of Medicine, New York, NY.
Simeon, D., Kozin, D., Segal, K., Lerch, B., Dujour, R.,& Giesbrecht, T. (2008). De-constructing depersonalization: Further evidence for symptom clusters. Psychiatry Research, 157, 303-306.
Steinberg, M. (2000). Advances in the clinical assessment of dissociation: The SCID-D-R. Bulletin of the Menninger Clinic, 64(2), 146-163.
Tutkun, H., Sar, V., Yargic, L., Ozpulat, T., Yanik, M., & Kiziltan, E. (1998). Frequency of dissociative disorders among psychiatric inpatients in a Turkish university clinic. American Journal of Psychiatry, 155, 800-805.
Van Ijzendoorn, M,m& Schuengel, C. (1996). The measurement of dissociation in normal and clinical populations: Meta-analytic validation of the dissociative experiences scale (DES). Clinical Psychology Review, 16, 365-382.
Xiao, Z.,Yan H., Wang, Z., Zhou, Z., Xu,Y., Chen, J., et al. (2006). Trauma and dissociation in China. American Journal of Psychiatry, 163(8), 1388-1391.
The moral of the story: do NOT trust Wikipedia as your source when it comes to psychiatry, psychology, or psychopharmacology. I don't know about the reliability of any other subjects. Also, anecdotes, friend-of-a-friend stories, and the unfortunate extremely dated prejudices of clinicians who decide they know better than the American Psychiatric Association and the American Medical Association (wow, I wish I were that smart!) are, in my opinion, not really the best sources. I'm sorry, but I really feel strongly about this one.
ETA: Oh yeah, and if anyone actually made it to the bottom of this Insanely Long Post (TM), the thing the layperson isn't likely to know (because there's almost no real public knowledge about the DD's), is that there are actually FIVE dissociative disorders, and DiD is only ONE of them.