Many people with PTSD also struggle with dissociation. This makes sense. Painful, traumatic events can cause tremendous emotional and mental disruption in a person's life. The trauma itself may be too difficult to confront or cope with, and therefore, the person may slip into a dissociative state in order to escape. When this dissociation becomes very severe, a dissociative disorder may develop.
There are several types of dissociative disorders, all of which cause a change in consciousness, memory, identity, or how one views his or her surroundings. This change can come on abruptly or slowly, and it may not happen all the time.
The Diagnostic and Statistical Manual of Mental Disorders, 4th Edition includes 5 types of dissociative disorders:
In dissociative amnesia, a person has one or more experiences of being unable to remember or recall important information about himself. This difficulty in remembering information goes beyond simple forgetfulness. The information that the person cannot recall is usually about some kind of traumatic or stressful event.
Someone with this disorder will suddenly forget about his past and unexpectedly travel away from home. The person may also experience some confusion about his identity or even assume a completely new identity.
Dissociative Identity Disorder
This disorder used to be called, "Multiple Personality Disorder." A person with dissociative identity disorder will have two or more separate identities that each have their own way of thinking and relating to the world. To have this disorder, a minimum of two of these identities must also take control over the person's behavior again and again. Finally, the person with dissociative identity disorder may also have difficulty remembering personal information that, like dissociative amnesia, goes beyond simple forgetfulness.
In depersonalization disorder, a person feels "detached from" their thoughts or body. For example, they may feel as though they are floating outside their body, looking at people through a window, or in a dream. Despite these experiences though, the person still stays in touch with reality.
Dissociative Disorder Not Otherwise Specified
This term is used by the DSM-IV to describe a dissociative disorder where the main feature is still some kind of dissociative experience, but criteria for other dissociative disorders are not present.
If you are interested in learning more about dissociation and dissociative disorders, especially with regard to PTSD, you can visit the website of the International Society for the Study of Trauma and Dissociation (ISSTD). This website provides a wealth of information on the connection between trauma and dissociation, as well as provides links to therapists who treat trauma and dissociation.