The DSM-5 states that all of these symptoms must be present to be diagnosed with DID:
"A. Disruption of identity characterized by two or more distinct personality states, which may be described in some cultures as an experience of possession. The disruption of marked discontinuity in sense of self and sense of agency, accompanied by related alterations in affect, behavior, consciousness, memory, perception, cognition, and/or sensory-motor functioning. These signs and symptoms may be observed by others or reported by the individual. B. Recurrent gaps in the recall of everyday events, important personal information, and/or traumatic events that are inconsistent with ordinary forgetting. C. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning. D. The disturbance is not a normal part of a broadly accepted cultural or religious practice. Note: In children, the symptoms are not better explained by imaginary playmates or other fantasy play. E. The symptoms are not attributable to the physiological effects of a substance (e.g., blackouts or chaotic behavior during alcohol intoxication) or another medical condition (e.g., complex partial seizures)."