Dissociative Identity Disorder

Dissociative identity (di-SO-see-a-tiv i-DEN-ti-tee) disorder (DID) is a mental disorder in which a person displays two or more distinct identities—sometimes called alters—that take control of behavior in turn. This disorder was formerly called multiple personality disorder.

Sybil's Story

Sybil Dorsett was a 22-year-old college student who had amnesia * . She also had terrible headaches and sometimes could not see, almost as if she were blind. After she asked for help from psychiatrist Cornelia Wilbur in New York, Sybil soon started to show other personalities. It was as if there were more than one person inside Sybil's body. One personality, who called herself Vicky, said she was from Paris. Another personality, called Peggy Lou, was a tough woman who showed no fear. As time passed, Sybil displayed more personalities: a writer, a flirt, a pianist, a mother, an infant, and even two men.

Wilbur noticed that each personality acted and sounded different from the Sybil Dorsett she had first met. Each personality even described his or her physical features in different ways. One said that she had blue eyes, whereas another said his eyes were brown. Almost everything, from details about hair color to gestures, changed as Sybil switched from one personality to another. In all, Sybil displayed 16 different identities.

Sybil's case became one of the most famous examples of dissociative identity disorder after a book about her experiences was published in 1973. A movie starring Sally Field as Sybil was made in 1976. Sybil's story offers a revealing glimpse of an often-misunderstood mental disorder.

What Is Dissociative Identity Disorder?

DID is a severe psychiatric condition in which a person has two or more distinct subpersonalities that periodically take control of his or her behavior. The subpersonalities are thought to be caused by repeated episodes of an extreme form of dissociation. Dissociation is a condition in which a perso n's thoughts, emotions, sensations, or memories become compartmentalized, usually as a result of a severe emotional trauma * or series of traumas. The symptoms of dissociation may include amnesia, depersonalization * , and derealization * . It is possible for survivors of natural disasters, plane crashes, criminal assaults, or military combat to develop dissociative symptoms without developing DID.

In contrast to dissociative symptoms that may develop in traumatized adults, DID is thought to begin early in life when a child is subjected to repeated incidents of physical or sexual abuse. The child splits off, or dissociates, memories of the abuse to survive. The memories later surface and are experienced in the form of a separate personality. This process can be repeated at different points in the child's development to form new alter personalities. The patient may eventually have as many as 100 alter personalities, although most patients display between 10 and 15 different personalities. Each alter personality takes control over the patient's behavior for a time, usually adopting a unique name, voice, dress style, and life history.

Descriptions of DID are found in ancient myths and many documents written throughout the centuries. However, until the early 1900s it was not regarded as a treatable mental disorder. At that time, Morton Prince (1854–1929), a Boston psychiatrist, treated a patient he called Sally Beauchamp who had four alter personalities. Prince used the term dissociation to describe his patient's symptoms. He published a book about Beauchamp in 1906 titled The Dissociation of a Personality. Much of what was learned about DID, however, was discovered during the last quarter of the 20th century.

DID should not be confused with schizophrenia *

How Common Is Dissociative Identity Disorder and Is It Contagious?

DID is a controversial diagnosis: some doctors believe it does not exist at all and others maintain that it is a subtype of post-traumatic stress disorder * . The number of reported cases of DID in the United States rose sharply between the 1970s and 1990s, but declined thereafter. Some researchers asserted that the increase occurred because doctors were increasingly aware of the disorder's symptoms. Others, however, speculated that the disorder was being diagnosed in some people because they were open to suggestion about memories of childhood trauma. Still other researchers noted that most cases of DID after the 1970s were reported in the United States and other English-speaking countries, which led to the possibility that DID is a by-product of certain cultures or periods in history rather than a universal and fixed psychiatric condition.

Estimates for incidence * from the American Psychiatric Association in the United States range from 0.01 to 1 percent of the general population, or between 30,000 and 300,000 people. These estimates vary widely because the disorder is difficult to diagnose. In addition, people with DID frequently suffer from other disorders such as depression * , alcoholism, drug addiction * , or personality disorders * . As a result, a doctor may think a patient's dissociative symptoms are caused by these other disorders and may not consider DID as a possible diagnosis. Consequently, a diagnosis of DID typically takes at least six to seven years to be made.

DID is not contagious.

How Do People Know They Have Dissociative Identity Disorder?

The first symptom of DID is amnesia. Like Sybil, people with the disorder often start to realize there are abnormally long periods they cannot remember. They might “wake up” in a different place or might be wearing different clothes and can recall nothing that explains the changes. In some cases, they find items in their closet they do not remember purchasing. There have even been cases of patients with DID who meet people at a party or on the street who call them by the name of one of their alters. Such episodes of amnesia can lead them to suspect that something is seriously wrong.

Patients often are skilled at hiding their alter personalities from family and friends. A person might be Sam, a shy clerk, at work. However, at night, he might lead life as Jack, an outgoing man who spends time in bars far from his neighborhood.

Other symptoms of DID include attempted suicide and self-inflicted injuries, such as cuts or burns. Many people with DID also show signs of post-traumatic stress disorder. They may startle easily or have nightmares or flashbacks * .


Herschel Walker, a former professional football player, was a high school superstar. In 1980 college recruiters made him the most soughtafter young athlete in the United States. Walker chose to play for the University of Georgia and helped that school to win the national collegiate football title. In 1982 he was awarded the Heisman Trophy, which is given each year to the most outstanding college football player. In 1983 Walker left college to become a professional athlete, playing with such teams as the Dallas Cowboys and Minnesota Vikings.

After retiring from professional sports, however, Walker began to notice he had memory problems. He could not remember the season he won the Heisman Trophy or even the dinner when the award was presented to him. His alter personalities emerged as bitter, angry people who threatened his wife with physical violence. On one occasion, Walker held a gun to his own head but could not remember the incident afterward. He then realized he had some kind of mental disorder and sought help. Diagnosed with DID in 2000, Walker wrote a book about his psychological problems, Breaking Free: My Life with Dissociative Identity Disorder (2008). He told his story in order to help other people with DID know the condition is treatable and they are not alone.

How Do Doctors Diagnose and Treat Dissociative Identity Disorder?


DID is usually diagnosed by psychiatrists or other mental health professionals rather than primary care doctors. The first step in diagnosis is to exclude any physical disease or condition that might be causing the patient's symptoms, such as head injuries, brain tumors, alcohol or drug abuse, or seizures * .

* to bring out different identities.

A psychiatrist may also use questionnaires or diagnostic interviews designed to help identify patients with DID. One brief screener is the Dissociative Experiences Scale, which patients can fill out in a doctor's office in a few minutes. If individuals score high on the test, they are scheduled for one or two longer interviews during which the doctor asks them to describe their experiences in detail. These interviews take between 45 and 90 minutes to complete.


The goal of treatment is to bring the separate identities together into one primary identity. Therapy attempts to help patients recall past trauma and deal with emotions without the primary identity being split into parts. Doctors may also prescribe medications to help patients cope with the anxiety and depression that often accompany DID. Success in treatment is possible, but treatment can take many years; it took about 11 years for Sybil's 16 personalities to blend into one. Patients with DID who are still emotionally attached to their abusers do not usually respond well to therapy.

Can Dissociative Identity Disorder Be Prevented?

DID can be prevented by healthy parenting and caregiving. Parents who are afraid they might abuse their children should contact a doctor or member of the clergy and ask for help in locating a parents' support group or a family therapist. Some churches, synagogues, and community centers offer parenting classes. Parents with children who have experienced a criminal attack or other traumatic event should also consult a doctor or mental health professional to help their children cope with their memories and feelings.

See also Anxiety and Anxiety Disorders: Overview • Depressive Disorders: Overview • Memory and Amnesia • Post-Traumatic Stress Disorder (PTSD) • Schizophrenia


Books and Articles

Schreiber, Flora Rheta. Sybil. New York: Warner Books, 1995. Trujillo, Olga. The Sum of My Parts: A Survivor's Story of Dissociative Identity Disorder. Oakland, CA: New Harbinger, 2011.


Rape, Abuse and Incest National Network. “Dissociation.” nn.org/get-information/effects-of-sexual-assault/dissociation (accessed December 4, 2015).


American Psychiatric Association. 1000 Wilson Blvd., Suite 1825, Arlington, VA 22209. Toll-free: 888-35-PSYCH. Website: http://www.psychiatry.org (accessed December 4, 2015).

American Psychological Association. 750 First St. NE, Washington, DC 20002-4242. Telephone: 202-336-5500. Website: http://www.apa.org (accessed December 4, 2015).

National Alliance on Mental Illness. 3803 N Fairfax Dr., Suite 100, Arlington, VA 22203. Toll-free: 800-950-6264. Website: http://www.nami.org (accessed December 4, 2015).

* amnesia (am-NEE-zha) is the loss of memory about one or more past experiences that is more than normal forgetfulness.

* trauma refers to a wound or injury, either psychological or physical. Psychological trauma refers to an emotional shock that leads to lasting psychological damage.

* depersonalization (dee-per-sonal- i-ZAY-shun) is a mental condition in which people feel they are living in a dream or are removed from their body and are watching themselves live.

* derealization (dee-reel-i-ZAY-shun) is a mental condition in which people feel the external world is strange or unreal.

* schizophrenia (skit-suh-FREE-neeuh) is a serious mental disorder that causes people to experience hallucinations, delusions, and other confusing thoughts and behaviors that distort their view of reality.

* post-traumatic stress disorder is a mental disorder that interferes with everyday living and occurs in people who survive a terrifying event, such as school violence, military combat, or a natural disaster.

* incidence means rate of occurrence.

* depression (dih-PRESH-un) is a mental state characterized by feelings of sadness, despair, and discouragement.

* addiction (uh-DIK-shun) is a strong physical or psychological dependence on a physical substance.

* personality disorders are a group of mental disorders characterized by long-term patterns of behavior that differ from those expected by society. People with personality disorders have patterns of emotional response, impulse control, and perception that differ from those of most people.

* flashbacks are intensely vivid, recurring mental images of a past traumatic event. People may feel or act as if they are reliving the experience.

* seizures (SEE-zhurs) are sudden bursts of disorganized electrical activity that interrupt the normal functioning of the brain, often leading to uncontrolled movements in the body and sometimes a temporary change in consciousness.

* hypnosis refers to a trancelike state, usually induced by another person. The person under hypnosis may recall forgotten or suppressed memories and may be unusually responsive to suggestions.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

(MLA 8th Edition)