In 1976, Sally Field won an Emmy Award for her portrayal of Sybil, a woman with at least 16 different personalities. That condition, previously known as multiple personality disorder (MPD), and now called dissociative identity disorder (DID), is one of the most controversial of all psychiatric diagnoses. In fact, the controversy is of such a degree that some in the psychiatric field believe that MPD/DID does not even exist.

According to at least one standard reference of psychological disorders, the DSM-IV, MPD/DID is defined by three major characteristics: at least two or more distinct personalities existing within an individual, with each personality being dominant (in control) at different times. The individual's behavior is determined by the personality that is dominant at any given time. Each of the separate, distinct personalities within the individual is complex and integrated with its own behavior patterns, social relationships, and name.

In general there is a principal identity that is rather passive, at times depressed , and has the individual’s name. There are differences in the physiological functions across the personalities, for example, different tolerance for pain, presence or absence of certain allergies or diseases, like asthma or even diabetes mellitus .

In addition to the above criteria when diagnosing MPD/DID, therapists and psychiatrists also look for the inability of a patient to remember important personal information or certain blocks of time (where such inability cannot be explained by normal forgetfulness). They also look for situations where the personality disorder suggesting MPD/DID cannot be explained by either substance abuse or by a general medical condition.

What Causes MPD/DID?

It is generally thought that MPD/DID is caused by extreme and prolonged trauma in childhood, such as childhood physical and/or sexual abuse. Some psychiatrists feel that other extreme and prolonged trauma such as being subject to combat, natural disasters, or severe emotional abuse can cause MPD/DID. The theory is that in order to deal with such extreme and prolonged trauma, a child will create alternative personalities to compartmentalize and thus deal with the ongoing trauma.

According to experts in the field, the original personality of a person with MPD/DID is often unaware of the other distinct, alternative personalities. Control of the individual is switched to an alternative personality by triggers that are often related in some way, at least in the patient's mind, to the underlying trauma that caused the disorder. When control switches back to the original personality, some patients do not recall any of the time when they were under the control of one of the alternative personalities, while others do remember. DID is basically the inability to integrate together the individual's memory function, his consciousness, and his identity.

Who Is Most Susceptible to MPD/DID?

Though the root of MPD/DID is thought to occur in childhood, it is generally not diagnosed until adolescence or adulthood. The condition is thought to lay dormant for many years (ie, until an individual reaches his 30s or 40s). A large majority of patients diagnosed with MPD/DID are women, though some in the field of psychiatry believe the incidence of the condition in men is greater than is diagnosed. The individuals with DID have high scores on measurements of their dissociative ability and their capacity to be hypnotized.

What Is the Treatment?

Although different therapists use different techniques to treat MPD/DID (as they do with many psychological conditions), there are four elements to the treatment of MPD/DID that appear to be widely accepted by experts in the field:

  • First, the therapist must diagnose the condition and communicate the condition to the patient. This task is considered quite difficult, since the patient may often react with both fear and disbelief.
  • Second, the therapist must acquire the trust of the individual. This too is considered quite difficult, since trust must be gained from each of the patient's distinct personalities.
  • Third, the therapist must help the patient to confront and work through the original trauma that underlies the MPD/DID. Depending on the severity of the patient's condition, this part of the process can take months or years.
  • And finally, the therapist tries to help the patient fuse, or integrate, the diverse and distinct alternative personality (or personalities) back into the patient's original personality.

What Is the Controversy?

The controversy around MPD/DID concerns whether it is a greatly underdiagnosed condition, or a condition that is grossly mis- (and thus over-) diagnosed. Consequently, there are widely varying estimates of how many people suffer from this disorder.

Mental health professionals who subscribe to the former theory estimate the incidence of MPD/DID in the general population to be at least 1%, and some feel the percentage is much higher. They feel that because MPD/DID is often accompanied by other (often severe) psychological conditions such as depression, phobias, and/or drug or alcohol abuse it is often overlooked or misdiagnosed.

Conversely, a growing majority of the mental health community believe that MPD/DID is (or at least has been) grossly overdiagnosed, a so-called "fad" diagnosis. They believe that, although MPD/DID exists, it is an extremely rare condition that occurs in only a handful of very disturbed individuals.

Some among this group of practitioners believe that the diagnosis is sometimes of an iatrogenic nature, meaning that the therapist, by looking too intensely for a particular condition, may actually cause the patient to believe she suffers from that condition, causing her to exhibit the symptoms. This makes a diagnosis of MPD/DID a kind of self-fulfilling prophecy. There is even a small subgroup in the mental health community who believe the condition may not exist at all.

Those who believe MPD/DID is greatly overdiagnosed (or doesn't exist at all) point to a number of reasons for this belief, including:

  • The aforementioned problem with iatrogenic diagnosis
  • The lack of medical literature referring to a condition with symptoms like or close to MPD/DID prior to the introduction of an official MPD/DID diagnosis in the mental health profession
  • The sudden growth of MPD/DID specialists and MPD/DID diagnosis when said diagnosis first came into vogue, and the subsequent decline of both diagnosis and specialists

Given the controversy among practitioners, what then is the lay public to conclude about MPD/DID? Is it a grossly underdiagnosed condition, a condition that doesn't exist at all, or somewhere in the middle?

Although virtually impossible to prove (due to the complexity of the condition and diagnosis, as well as the "soft science" nature of psychology in general), the majority of practitioners seem to believe that the clinical manifestation of MPD/DID is a real but extremely rare condition.

According to Dr. Jeffrey Miner, a Boston-area clinical and forensic psychologist who has evaluated criminal defendants claiming to suffer from MPD/DID, "I'm convinced that MPD/DID exists, but I'm equally certain that genuine cases are quite rare." Dr. Miner further notes that although he thought there was a fad-like quality to the diagnosis and that it may have been overdiagnosed for a few years, most practitioners are very careful before they make a diagnosis of MPD/DID. Dr. Miner further notes that realistically, such a diagnosis should only be made over a significant period of time, not on the basis of just a few interviews with a client.

Seeking Help

Finally, Dr. Miner points out that if you think you suffer from a multiple personality disorder, or are concerned because you are suffering from periods of amnesia for various events, don't try and diagnose the condition. Instead, Miner stresses, you should find a qualified licensed psychologist or psychiatrist who practices therapy and discuss your concerns openly and honestly.