Dissociative Identity Disorder 295
United States, Canada, and Europe among th ose with the disorder is about 90%. Other
forms of traumatizing experiences, includin g childhood medical and surgical procedures,
war, childhood prostitution, and terrorism, have been reported.
Course modifiers. Ongoing abuse, later-life retrauma tization, comorbid ity with mental
disorders, severe medical illness, and delay in appropriate treatment are associated with
poorer prognosis.
Culture-Related Diagnostic Issues 
Many features of dissociative identity disord er can be influenced by the individual’s cul-
tural background. Individuals with this disorder may pres ent with prominent medically
unexplained neurological symptoms, such as no n-epileptic seizures, paralyses, or sensory
loss, in cultural settings where such symptoms are common. Similarly, in settings where
normative possession is common (e.g., rural areas in the developing world, among certain
religious groups in the United States and Euro pe), the fragmented identities may take the
form of possessing spirits, de ities, demons, animals, or myth ical figures. Acculturation or
prolonged intercultural contact may shape the characteristics of  the other identities (e.g.,
identities in India may speak English exclu sively and wear Western clothes). Possession-
form dissociative identity diso rder can be distinguished from  culturally accepted posses-
sion states in that the former is involunta ry, distressing, uncontro llable, and often recur-
rent or persistent; involves conflict between  the individual and his or her surrounding
family, social, or work milieu; and is manifest ed at times and in places that violate the
norms of the culture or religion. 
Gender-Related Diagnostic Issues
Females with dissociative identity disorder pr edominate in adult clinical settings but not