Causes of Multiple Personality Disorder

Multiple personality disorder, or dissociative personality disorder, is a syndrome marked by the apparent existence of two or more personalities in a single person. Multiple personality disorder generally shows up in conjunction with a spectrum of other disorders such as post traumatic stress disorder, suicidal behavior, and eating disorders, and is therefore more difficult than one might anticipate to diagnose.

Generally, multiple personality disorder is triggered by childhood trauma, often physical or sexual abuse or both. Often, the memory of the abuse has been suppressed and must be recovered through psychotherapy. This comes with its own dangers; recently, it’s been shown that psychotherapists, without realizing it, can lead a person to invent “suppressed” memories, and these cases have led to irreparable harm to innocent people who are accused of child abuse by the children and relatives they love.

However, multiple personality disorder is sometimes triggered by purely organic causes. For instance, temporal lobe epilepsy sometimes can lead to personality split. Other organic causes of multiple personality disorder include sleep loss, sensory deprivation, stroke, Alzheimer’s, and encephalitis. Or the corpus callosum (the part of the brain that joins the left and right halves of the cerebral cortex) may be severed due to trauma or surgery designed to cure severe epilepsy, and this may in turn cause the rise of multiple personalities. This particular type of MPD is often described as “Jekyll and Hyde,” because the two halves act as two independent entities – two dominant personalities, instead of the traditional dominant single personality and subordinate other personality or personalities.

If the multiple personality disorder is caused by childhood trauma, it is likely remembered only as a series of perceptual information – fleeting images, olfactory, auditory, or olfactory sensations. Broca’s area, a part of the brain intimately involved in transforming experience into speech, is often very suppressed during the recovery of true memories, making it almost impossible for the patient to express in coherent terms their experience and memories. At the same time, parts of the right brain associated with visual and sensory memory are highly stimulated. The patient is, in essence, “reliving” the trauma. This is often described as flashbacks.

Because of this, psychotherapists and researchers theorize that part of what’s happening is the sequestering of harmful information. Instead of sharing space with the rest of the memories, the traumatic incidences are shoved into their own little corner, and the only way they can be accessed is through fragmented and incoherent neural pathways.

Ultimately, there is no way to know for certain what causes multiple personality disorder. Researchers are constantly examining this little-understood area of psychology, and are making new discoveries every day.