Dissociative disorders are characterized by alterations in consciousness, memory, identity, or perception of the environment or self, through which the patient involuntarily escapes (or "dissociates") from reality. Dissociative disorders are classified depending on the predominant symptoms experienced and include dissociative amnesia, dissociative identity disorder, and depersonalization disorder.

Exact incidence is unknown, with estimates around 2% or more of the general population, and women are more commonly diagnosed. Earlier onset of symptoms is associated with increased severity. A childhood history of abuse or neglect is common and often overlooked or minimized. Risk factors include physical or emotional abuse, as well as exposure to combat, violence, or natural disasters.

The presenting features for all dissociative disorders include temporary alterations in the patient's relation to reality. Dissociative identity disorder presents with 2 or more distinct personality states (formally multiple personality disorder); dissociative amnesia presents with partial or complete loss of memory for psychologically stressful events; dissociative amnesia with fugue state presents with sudden, unexplained travel and inability to recall features of one's past or identity; and dissociative depersonalization / derealization presents with the sensation of an out-of-body experience or feeling completely detached from one's self or surroundings.

Comorbid conditions include mood disorders, anxiety disorders, posttraumatic stress disorder, and functional neurological disorders. Suicide is common among patients with dissociative disorders, especially dissociative identity disorder.

Dissociative disorders can be transient or recurrent. Treatment includes psychotherapy and medication. Patients with these disorders may have an increased risk of various general medical conditions.