In psychiatry, dissociation is defined as an unconscious defense mechanism involving the segregation of any group of mental or behavioral processes from the rest of the person’s psychic activity. Dissociative disorders involve this mechanism so that there is a disruption in one or more mental functions, such as memory, identity, perception, consciousness, or motor behavior.
Dissociative amnesia is a dissociative condition which involves an inability to recall important personal information, usually of a traumatic or stressful nature, that is too extensive to be explained by normal forgetfulness.
Depersonalization and Derealization are types of dissociative experiences. DSM 5 defines Depersonalization as experiences of unreality, detachment or being an outside observer about one’s thoughts, feelings, sensations, body or action (for example emotional and physical numbing or feeling like an automaton or watching self in a movie). Derealization is defined as experiences of unreality or detachment with respect to surroundings (for example dreamlike, foggy, life less experiences). Dissociation is related to trauma and is considered a response or maybe a defense mechanism to the experienced traumatic events.
Dissociative Identity disorder is another dissociation condition that is characterized by the presence of two or more distinct identities or personality states each presents as having its own pattern of perceiving, relating to, and thinking about the environment and self (Diagnostic and Statistical Manual of Mental Disorders, 2013; Kaplan and Sadock’s Synopsis of Psychiatry, 2015).