What Is Multiple Personality Disorder?

Also known as dissociative identity disorder, this psychiatric disorder is characterized by an individual exhibiting more than one distinct personality.

Life with Multiple Personality Disorder

Multiple Personality Disorder, commonly referred to as Dissociative Identity Disorder, is a mental disorder where a single individual develops two or more distinct and independent personalities who are usually completely unaware of each other’s presence. In some cases, the individual has a dominant personality and one or more subordinate personalities. The dominant personality completely loses tracks of the time when the subordinate personality takes control but the latter might remember the dominant personality as a completely different individual, often criticizing the actions of that individual. The various personalities are so different from each other that they might even develop different handwriting styles or have different electroencephalogram readings.

Presentation and Symptoms

Some famous cases of multiple personality disorder has revealed just how seriously this disorder can influence the person suffering from it. In the late 1970s, an American citizen named Billy Milligan became the subject of a highly controversial court case. He was committed with several felonies and three rapes. However, when psychologists interacted with him in the course of his defense, he was diagnosed with multiple personality disorder and was believed to bear 24 distinct personalities with two of his personalities, a Russian man and a lesbian woman, being held responsible for committing the crimes. He became the first person to be acquitted of a major crime for multiple personality disorder. His life story became the subject matter of book, films and music after his death from cancer in 2014. Daniel Keyes's famous novel “The Minds of Billy Milligan” is based on his story. The symptoms of individuals with multiple personality disorder is wide and varied depending on the of personalities possessed by the person (which can vary between 2 and all the way to 100). The symptoms, however, cannot be explained by seizures, substance abuse or other medical conditions. Malingering is possible in some cases and so is the possibility of a factitious disorder. Each personality is endowed with its own self-image, behavior and habits, separate names and separate physical expressions. Self destructive and aggressive behavior is not uncommon. Depression, anxiety and guilt often engulfs the person suffering from the complex disorder and frequent gaps in memories traumatizes the person as he or she is unable to recollect any of the events that happen during a switch to another personality.

How Common Is It?

Some of the first cases of what we would now recognize as multiple personality disorder were described by Swiss German scientist Paracelsus in the 16th Century. Very little data on the prevalence of multiple personality disorder globally, however, exists to this date. It is, however, believed that 1-3% of the population suffers from this disorder. Females are known to be affected 5 to 9 times more than males which could also be due to the fact that men often go undiagnosed as they are already locked up in jail as a result of the crimes committed by their more aggressive personalities. The disease is more common in young adults and gradually declines with age. In children, though rarely diagnosed at such a young age, rates among males and females are nearly equal. The number of cases of patients with the disorder has risen sharply in the latter part of the last century with 40,000 reported cases being known at the end of the 20th Century from less that 200 cases being reported before 1970.


Treatment of multiple personality disorder is aimed at integrating the separate personalities into a single one. This is a long term process, necessitating thorough psychiatric counselling of the patient. There is a need to identify the root cause of the disease such as childhood abuse or other forms of trauma that triggered the disorder in the individual. The trauma needs to be brought to conscious awareness of the patient and the fears etched in the person's subconscious mind needs to be deleted completely. The dominant personality of the patient also needs to be made conscious about the other personalities to allow the dominant personality to gradually subdue the other personalities so that the person emerges with a uniform personality.

Ongoing Research

The rarity and highly complex nature of the multiple personality disorder makes it extremely difficult to study, diagnose and treat this disorder. The occurrence of this disorder shows us clearly how little we know about the human brain and conscience. To understand the disease better, there is need to study the human brain and its processes more thoroughly. Intense research needs to be conducted in the fields of neuroscience and psychology to arrive at some conclusion about the cause and detailed scientific explanation of the multiple personality disorder. Only then it will be possible to develop proper diagnostic tools and treatment options for the patients of this disorder.

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