Possession-form identities in dissociative identity disorder typically manifest as be- haviors that appear as if a "spirit,” supernatural being, or outside person has taken control, such that the individual begins speaking or acting in a distinctly different manner. For ex- ample, an individual’s behavior may give the appearance that her identity has been replaced by the "ghost” of a girl who committed suicide in the same community years before, speaking and acting as though she were still alive. Or an individual may be ”taken over" by a demon or deity, resulting in profound impairment, and demanding that the in- dividual or a relative be punished for a past act, followed by more subtle periods of iden- tity alteration. However, the majority of possession states around the world are normal, usually part of spiritual practice, and do not meet criteria for dissociative identity disor- der. The identities that arise during possession-form dissociative identity disorder present recurrently, are unwanted and involuntary, cause clinically significant distress or impair- ment (Criterion C), and are not a normal part of a broadly accepted cultural or religious practice (Criterion D).
Individuals with dissociative identity disorder typically present with comorbid depression, anxiety, substance abuse, self—injury, non-epileptic seizures, or another common symp- tom. They often conceal, or are not fully aware of, disruptions in consciousness, amnesia, or other dissociative symptoms. Many individuals with dissociative identity disorder re- port dissociative ﬂashbacks during which they undergo a sensory reliving of a previous event as though it were occurring in the present, often with a change of identity, a partial or complete loss of contact with or disorientation to current reality during the ﬂashback, and a subsequent amnesia for the content of the ﬂashback. Individuals with the disorder typically report multiple types of interpersonal maltreatment during childhood and adult- hood. Nonmaltreatment forms of overwhelming early life events, such as multiple long, painful, early-life medical procedures, also may be reported. Self-mutilation and suicidal behavior are frequent. On standardized measures, these individuals report higher levels of hypnotizability and dissociativity compared with other clinical groups and healthy con- trol subjects. Some individuals experience transient psychotic phenomena or episodes.
Several brain regions have been implicated in the pathophysiology of dissociative identity disorder, including the orbitofrontal cortex, hippocampus, parahippocampal gyrus, and amygdala.
The 12-month prevalence of dissociative identity disorder among adults in a small U.S.
community study was 1.5%. The prevalence across genders in that study was 1.6% for males and 1.4% for females.
Dissociative identity disorder is associated with overwhelming experiences, traumatic events, and / or abuse occurring in childhood. The full disorder may first manifest at al- most any age (from earliest childhood to late life). Dissociation in children may generate problems with memory, concentration, attachment, and traumatic play. Nevertheless, chil- dren usually do not present with identity changes; instead they present primarily with over- lap and interference among mental states (Criten'on A phenomena), with symptoms related to discontinuities of experience. Sudden changes in identity during adolescence may ap- pear to be just adolescent turmoil or the early stages of another mental disorder. Older individuals may present to treatment with what appear to be late-life mood disorders, ob- sessive-compulsive disorder, paranoia, psychotic mood disorders, or even cognitive dis- orders due to dissociative amnesia. In some cases, disruptive affects and memories may increasingly intrude into awareness with advancing age.
moval from the traumatizing situation (e.g., through leaving home); 2) the individual's children reaching the same age at which the individual was originally abused or trauma- tized; 3) later traumatic experiences, even seemingly inconsequential ones, like a minor motor vehicle accident; or 4) the death of, or the onset of a fatal illness in, their abuser(s).