General psychiatric assessment instruments do not cover DSM-IV dissociative disorders. Many large-scale epidemiological studies led to biased results due to this deficit in their methodology. Nevertheless, screening studies using diagnostic tools designed to assess dissociative disorders yielded lifetime prevalence rates around 10% in clinical populations and in the community. Special populations such as psychiatric emergency ward applicants, drug addicts, and women in prostitution demonstrated the highest rates. Data derived from epidemiological studies also support clinical findings about the relationship between childhood adverse experiences and dissociative disorders. Thus, dissociative disorders constitute a hidden and neglected public health problem. Better and early recognition of dissociative disorders would increase awareness about childhood traumata in the community and support prevention of them alongside their clinical consequences. 1. Introduction Dissociation is defined as a disruption in the usually integrated functions of consciousness, memory, identity, or perception of the environment . Dissociative disorders constitute a group of clinical syndromes covering disturbances attributed to one or more of these domains. Dissociation may be sudden or gradual, transient, or chronic. Being the most chronic and complex type of dissociative disorders, dissociative identity disorder (DID) constitutes an overarching syndrome covering all dissociative phenomena. Depersonalization disorder, dissociative amnesia, and dissociative fugue are further categories of dissociative disorders. Dissociative conditions which do not fit diagnostic criteria of these specific categories are diagnosed as having dissociative disorder not otherwise specified (DDNOS). Although not specified as such in official classification systems, the concept of chronic complex dissociative disorder deserves a rather detailed description here, because it is a significant category for epidemiological studies in particular. Due to the tight definition of DID in DSM-IV , a larger group of subjects who are close to DID in their symptomatology are being diagnosed as having the type-1 of the dissociative disorder not otherwise specified (DDNOS-1). The latter group is consisted of the subjects who have identity alteration without dissociative amnesia or whose identity alteration is too mild to fit the diagnostic criterion of DID. In fact, the difference between two categories is a matter of severity but not a qualitative one. Thus, DID and DDNOS-1 constitute the chronic complex
C. A. Ross, S. D. Miller, P. Reagor, L. Bjornson, G. A. Fraser, and G. Anderson, “Structured interview data on 102 cases of multiple personality disorder from four centers,” American Journal of Psychiatry, vol. 147, no. 5, pp. 596–601, 1990.
V. Sar, T. Kundakci, E. Kiziltan et al., “The axis-I dissociative disorder comorbidity of borderline personality disorder among psychiatric outpatients,” Journal of Trauma and Dissociation, vol. 4, no. 1, pp. 119–136, 2003.
V. Sar, G. Akyuz, N. Kugu, E. Ozturk, and H. Ertem-Vehid, “Axis I dissociative disorder comorbidity in borderline personality disorder and reports of childhood trauma,” Journal of Clinical Psychiatry, vol. 67, no. 10, pp. 1583–1590, 2006.
V. Sar, G. Akyüz, T. Kundak？i, E. Kiziltan, and O. Do？an, “Childhood trauma, dissociation, and psychiatric comorbidity in patients with conversion disorder,” American Journal of Psychiatry, vol. 161, no. 12, pp. 2271–2276, 2004.
M. Rufer, D. Held, J. Cremer et al., “Dissociation as a predictor of cognitive behavior therapy outcome in patients with obsessive-compulsive disorder,” Psychotherapy and Psychosomatics, vol. 75, no. 1, pp. 40–46, 2006.
R. A. Lanius, E. Vermetten, R. J. Loewenstein et al., “Emotion modulation in PTSD: clinical and neurobiological evidence for a dissociative subtype,” American Journal of Psychiatry, vol. 167, no. 6, pp. 640–647, 2010.
M. B. First, R. L. Spitzer, M. Gibbon, and J. B. Williams, Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I), Clinician Version, User's Guide, American Psychiatric Association, Washington, DC, USA, 1997.
G. Andrews, S. Henderson, and W. Hall, “Prevalence, comorbidity, disability and service utilisation: overview of the Australian National Mental Health Survey,” British Journal of Psychiatry, vol. 178, pp. 145–153, 2001.
H. J. Jackson and P. M. Burgess, “Personality disorders in the community: results from the Australian National Survey of Mental Health and Well-Being Part III—relationships between specific type of personality disorder, Axis 1 mental disorders and physical conditions with disability and health consultations,” Social Psychiatry and Psychiatric Epidemiology, vol. 39, no. 10, pp. 765–776, 2004.
R. V. Bijl, A. Ravelli, and G. van Zessen, “Prevalence of psychiatric disorder in the general population: results of The Netherlands Mental Health Survey and Incidence Study (NEMESIS),” Social Psychiatry and Psychiatric Epidemiology, vol. 33, no. 12, pp. 587–595, 1998.
C. A. Ross, G. Anderson, W. P. Fleisher, and G. R. Norton, “The frequency of multiple personality disorder among psychiatric inpatients,” American Journal of Psychiatry, vol. 148, no. 12, pp. 1717–1720, 1991.
H. Tutkun, V. Sar, L. I. Yargic, T. Ozpulat, M. Yanik, and E. Kiziltan, “Frequency of dissociative disorders among psychiatric inpatients in a Turkish university clinic,” American Journal of Psychiatry, vol. 155, no. 6, pp. 800–805, 1998.
T. Lipsanen, J. Korkeila, P. Peltola, J. J？rvinen, K. Langen, and H. Lauerma, “Dissociative disorders among psychiatric patients: comparison with a nonclinical sample,” European Psychiatry, vol. 19, no. 1, pp. 53–55, 2004.
C. Mueller, H. Moergeli, H. Assaloni, R. Schneider, and M. Rufer, “Dissociative disorders among chronic and severely impaired psychiatric outpatients,” Psychopathology, vol. 40, no. 6, pp. 470–471, 2007.
C. A. Ross, C. M. M. Duffy, and J. W. Ellason, “Prevalence, reliability and validity of dissociative disorders in an inpatient setting,” Journal of Trauma and Dissociation, vol. 3, no. 1, pp. 7–17, 2002.
U. Gast, F. Rodewald, V. Nickel, and H. M. Emrich, “Prevalence of dissociative disorders among psychiatric inpatients in a German University Clinic,” Journal of Nervous and Mental Disease, vol. 189, no. 4, pp. 249–257, 2001.
K. Ginzburg, E. Somer, G. Tamarkin, and L. Kramer, “Clandestine psychopathology: unrecognized dissociative disorders in inpatient psychiatry,” Journal of Nervous and Mental Disease, vol. 198, no. 5, pp. 378–381, 2010.
M. Friedl, N. Draijer, and P. de Jonge, “Prevalence of dissociative disorders in psychiatric in-patients: the impact of study characteristics,” Acta Psychiatrica Scandinavica, vol. 102, no. 6, pp. 423–428, 2000.
J. G. Johnson, P. Cohen, S. Kasen, and J. S. Brook, “Dissociative disorders among adults in the community, impaired functioning, and axis I and II comorbidity,” Journal of Psychiatric Research, vol. 40, no. 2, pp. 131–140, 2006.
E. C. M. Hunter, M. Sierra, and A. S. David, “The epidemiology of depersonalisation and derealisation—a systematic review,” Social Psychiatry and Psychiatric Epidemiology, vol. 39, no. 1, pp. 9–18, 2004.
N. G. Waller, F. W. Putnam, and E. B. Carlson, “Types of dissociation and dissociative types: a taxometric analysis of dissociative experiences,” Psychological Methods, vol. 1, no. 3, pp. 300–321, 1996.
R. T. Mulder, A. L. Beautrais, P. R. Joyce, and D. M. Fergusson, “Relationship between dissociation, childhood sexual abuse, childhood physical abuse, and mental illness in a general population sample,” American Journal of Psychiatry, vol. 155, no. 6, pp. 806–811, 1998.
J. Vanderlinden, R. van Dyck, W. Vandereycken, and H. Vertommen, “Dissociation and traumatic experiences in the general population of The Netherlands,” Hospital and Community Psychiatry, vol. 44, no. 8, pp. 786–788, 1993.
J. Vanderlinden, R. van Dyck, W. Vandereycken, and H. Vertommen, “The Dissociation Questionnaire (DIS-Q). Development and characteristics of a new self-reporting Questionnaire,” Clinical Psychology and Psychotherapy, vol. 1, pp. 21–27, 1991.
F. Karadag, V. Sar, D. Tamar-Gürol, C. Evren, M. Karagoz, and M. Erkiran, “Dissociative disorders among inpatients with drug or alcohol dependency,” Journal of Clinical Psychiatry, vol. 66, no. 10, pp. 1247–1253, 2005.
D. Tamar-Gürol, V. Sar, F. Karadag, C. Evren, and M. Karagoz, “Childhood emotional abuse, dissociation, and suicidality among patients with drug dependency in Turkey,” Psychiatry and Clinical Neurosciences, vol. 62, no. 5, pp. 540–547, 2008.
C. A. Ross, J. Kronson, S. Koensgen, K. Barkman, P. Clark, and G. Rockman, “Dissociative comorbity in 100 chemically dependent patients,” Hospital and Community Psychiatry, vol. 43, no. 8, pp. 840–842, 1992.
J. W. Ellason, C. A. Ross, K. Sainton, and L. W. Mayran, “Axis I and II comorbidity and childhood trauma history in chemical dependency,” Bulletin of the Menninger Clinic, vol. 60, no. 1, pp. 39–51, 1996.
I. Sch？fer, W. Langeland, J. Hissbach et al., “Childhood trauma and dissociation in patients with alcohol dependence, drug dependence, or both—a multi-center study,” Drug and Alcohol Dependence, vol. 109, no. 1–3, pp. 84–89, 2010.
C. A. Ross, G. Anderson, S. Heber, and G. R. Norton, “Dissociation and abuse among multiple-personality patients, prostitutes, and exotic dancers,” Hospital and Community Psychiatry, vol. 41, no. 3, pp. 328–330, 1990.
L. I. Yargic, M. Sevim, G. Arabul, and S. Y. Ozden, “Childhood trauma histories and dissociative disorders among prostitutes in Turkey,” in Proceedings of the Annual Conference of the International Society for the Study of Dissociation, San Antonio, Tex, USA, 2000.
E. B. Carlson, F. W. Putnam, C. A. Ross et al., “Validity of the dissociative experiences scale in screening for multiple personality disorder: a multicenter study,” American Journal of Psychiatry, vol. 150, no. 7, pp. 1030–1036, 1993.
S. S. Zoroglu, U. Tuzun, V. Sar et al., “Suicide attempt and self-mutilation among Turkish high school students in relation with abuse, neglect and dissociation,” Psychiatry and Clinical Neurosciences, vol. 57, no. 1, pp. 119–126, 2003.
E. R. S. Nijenhuis, P. Spinhoven, R. van Dyck, O. van der Hart, and J. Vanderlinden, “The development and psychometric characteristics of the Somatoform Dissociation Questionnaire (SDQ-20),” Journal of Nervous and Mental Disease, vol. 184, no. 11, pp. 688–694, 1996.
E. Tezcan, M. Atmaca, M. Kuloglu, O. Gecici, A. Buyukbayram, and H. Tutkun, “Dissociative disorders in Turkish inpatients with conversion disorder,” Comprehensive Psychiatry, vol. 44, no. 4, pp. 324–330, 2003.
J. R. Ogawa, L. A. Sroufe, N. S. Weinfield, E. A. Carlson, and B. Egeland, “Development and the fragmented self: longitudinal study of dissociative symptomatology in a nonclinical sample,” Development and Psychopathology, vol. 9, no. 4, pp. 855–879, 1997.
V. Sar and E. Ozturk, “Psychotic symptoms in complex dissociative disorders,” in Psychosis, Trauma and Dissociation: Emerging Perspectives on Severe Psychopathology, A. Moskowitz, I. Schaefer, and M. Dorahy, Eds., pp. 165–175, Wiley Press, New York, NY, USA, 2008.