In order to explain dissociative disorders, please read this interesting article from NAMI:

The symptoms of a dissociative disorder usually first develop as a response to a traumatic event, such as abuse or military combat, to keep those memories under control. Stressful situations can worsen symptoms and cause problems with functioning in everyday activities. However, the symptoms a person experiences will depend on the type of dissociative disorder that a person has.

Symptoms and signs of dissociative disorders include:

Significant memory loss of specific times, people and events
Out-of-body experiences, such as feeling as though you are watching a movie of yourself
Mental health problems such as depression, anxiety and thoughts of suicide
A sense of detachment from your emotions, or emotional numbness
A lack of a sense of self-identity