trauma-generated neurobiological responses. Biologically derived traits and epigenetic mechanisms are also likely to be at play. At this point, no direct examination of genetics has occurred in DID. However, it is likely to exist, given the genetic link to dissociation in general and in relation to childhood adversity in particular." Stating that there is "a lack of understanding regarding the etiopathology of DID", Blihar adds that "many researchers and psychiatrists regard DID as the most severe form of a childhood onset post-traumatic stress disorder (PTSD) because it is virtually impossible to find a DID patient without a history of PTSD. ... There are currently two competing theories regarding the relationship between trauma and dissociation: the trauma-related model and the fantasy-prone model." The DSM-5 diagnostic manual states that DID is "associated with overwhelming experiences, traumatic events, and/or abuse during childhood". Other risk factors reported include childhood neglect, childhood medical procedures, war, terrorism, and childhood prostitution. Dissociative disorders frequently occur after trauma, and the DSM5 places them after the trauma and stressor-related disorders to reflect this close relationship. Disturbed and altered sleep has also been suggested as having a role in dissociative disorders in general and specifically in DID, alterations in environments also largely affecting the DID patient. Developmental trauma People diagnosed with DID often report that they have experienced physical or sexual abuse during childhood (although the accuracy of these reports has been disputed); others report overwhelming stress, serious medical illness or other traumatic events during childhood. They also report more historical psychological trauma than those diagnosed with any other mental illness. Severe sexual, physical, or psychological trauma in childhood has been proposed as an explanation for its development; awareness, memories and emotions of harmful actions or events caused by the trauma are removed from consciousness, and alternate personalities or subpersonalities form with differing memories, emotions and behavior. DID is attributed to extremes of stress or disorders of attachment. What may be expressed as post-traumatic stress disorder (PTSD) in adults may become DID when occurring in children, possibly due to their greater use of imagination as a form of coping. Possibly due to developmental changes and a more coherent sense of self past the age of six, the experience of extreme trauma may result in different, though also complex, dissociative symptoms and identity disturbances. A specific relationship between childhood abuse, disorganized attachment, and lack of social support are thought to be