According to the mental health treatment guidelines for dissociative disorders, a dissociative disorder is a psychological disorder in which dissociation is the most important and central characteristic. Dissociation is a disruption and / or interruption of normal psychological functioning, which affects, among other things, thinking, memory, identity, emotion, perception, body experience, motor control and behavior. Dissociative symptoms can disrupt any area of psychological functioning.

The DSM-5 is the Diagnostic and Statistical Manual of Mental Disorders: the diagnostic and statistical handbook of psychiatric disorders. According to DSM-5, the following symptoms must be present for dissociative identity disorder (DID) to be diagnosed:

• Fragmentation of identity characterized by two or more distinct personality states. This fragmentation includes a clear discontinuity in self-experience and the sense of self-control. The fragmentation is accompanied by changes in affect, behavior, consciousness, memory, perception, cognitive and / or sensorimotor functioning.

• Recurring gaps in remembering everyday events, important personal information and / or psychotraumatic events.

• The symptoms cause clinically significant distress or impairment of functioning.

• The disorder is not part of a generally accepted cultural or religious practice.

• Symptoms cannot be attributed to the physiological effects of a substance or to a general medical condition.

(source: DSM-5: American Psychiatric Association. (2013). Diagnostic and Statistical manual of mental health disorders (5th ed.).Washington, DC).