Dissociative disorders are forms of dissociation in which one or more mental processes are dissociated, or split off, from the rest of the personality. For example, in schizophrenia, an individual may think he or she hears voices or noises, or sees things. Dissociative disorders are a subconscious attempt to protect the victim from threatening emotions or situations, or to suppress violent or unacceptable impulses.
Multiple personality disorder, or dissociative personality disorder, is a dissociative disorder where two or more distinct and different personalities inhabit the same person. It’s quite rare, being confirmed in only a few hundred personalities. The personalities in a multiple personality disorder often exist without being truly aware of one another. Often, one personality is dominant, occupying the patient most of the time to the exclusion of the other personalities. The subordinate personalities in these cases may be aware of the dominant personality, and may be quite critical of the dominant personality as if it were a separate person. This leads to a kind of amnesia, in which the dominant personality is completely unaware of the things the subordinate personalities have done in its absence.
Patients with multiple personality disorder will display personalities that are very different in outlook and temperament, and will also have different body language and handwriting. The different personalities generally have different first names. Electroencephalogram readings and projective tests given to the different personalities have very different results, leading to the conclusion that they are the readings of different people.
Generally, multiple personality disorder is seen as having arisen from childhood trauma, often physical or sexual abuse. It allows the patient to split off from conscious awareness difficult, painful, or conflicting thoughts, feelings, and emotions. In this manner, the formation of multiple personalities can be seen as a method of coping with the very real emotional turmoil in a disturbed person.
People who have multiple personality disorder often have surprisingly normal lives, as the dominant personality is generally the one running things every day. In their intimate lives, though, multiple personality victims often have difficulty bonding and trusting others, and when they do, the multiple personalities that eventually come to the surface may sabotage the growing relationship.
Treatment of multiple personality disorder is generally focused on reintegrating the different personalities into a single personality. If there is a dominant personality, this treatment focuses on making that personality aware of the reality of the other personalities, generally after the trauma that caused the initial split has been brought to conscious awareness and treated.