Epidemiology of Dissociative Disorders: An Overview
Vedat Sar – Department of Psychiatry, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey 2011
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.
“Most of the published clinical case series are focused on chronic and complex forms of dissociative disorders.
Data collected in diverse geographic locations such as North America , Puerto Rico , Western Europe , Turkey , and Australia  underline the consistency in clinical symptoms of dissociative disorders. These clinical case series have also documented that dissociative patients report highest frequencies of childhood psychological trauma among all psychiatric disorders. Childhood sexual (57.1%–90.2%), emotional (57.1%), and physical (62.9%–82.4%) abuse and neglect (62.9%) are among them (2–6).”
“Several studies conducted on consecutive series of inpatients and outpatients in general psychiatric settings in diverse countries yielded
results depending on the hinterland of the particular institution (Table 1).
Two studies in North America demonstrated that 13.0–20.7 % of psychiatric inpatients had a dissociative disorder [22, 23]. Studies on dissociative disorders in Istanbul, Turkey, yielded a prevalence slightly above 10% among psychiatric inpatients and outpatients [8, 24, 25]. Although still considerable, these rates were lower in the Netherlands , Germany , and Switzerland  among inpatients, that is, between 4.3%–8.0%. A Finnish study  reported higher rates for psychiatric outpatients (14.0%) and inpatients (21.0%).
Emergency admissions of a university psychiatric clinic in Istanbul, Turkey yielded the highest rate in the country: 35.7% . In a study from Zurich, Switzerland, among severely impaired psychiatric outpatients, prevalence of all dissociative disorders were 25.0% . Two recent studies on inpatient and outpatient psychiatric units in North America reported higher rates than those of the previous studies [31, 32].”