This study aims to evaluate the neurobiological basis of traumatic dissociation in a cross-diagnostic sample of women who have histories of childhood abuse and neglect.

Dissociative symptoms commonly are associated with exposure to traumatic stress. Preliminary evidence from functional magnetic resonance imaging-based analysis (fMRI) of neural activation during dissociative symptom provocation in patients with PTSD or DID has implicated certain key structures involved in the generation of dissociative symptoms. Given the presumed region-to-region neural interplay implicit within this model, the investigators believe the use of intrinsic functional connectivity MRI (fcMRI) represents a valuable next line of investigation into the neurobiology of traumatic dissociation. The investigators also believe that a genetic approach holds promise as another converging line of inquiry into our understanding of traumatic dissociation.

To evaluate the neurobiological basis of traumatic dissociation, this study will recruit patients with PTSD or DID, and recruit matched controls to identify neurobiological correlates of traumatic dissociation.The study will compare the phenomenology of traumatic dissociation in patients with different PTSD subtypes and DID using standardized measures to look at the neurological and genetic correlates.

This study will also include a follow up visit that includes neuroimaging and genetic assessments.

Inclusion Criteria:

• Female
• Clinical diagnosis of PTSD or DID and history of childhood abuse, or healthy controls
• Age between 18 and 89
• Legal and mental competency of the patient

Exclusion Criteria:

• Male
• Under 18 or over 89
• Legal or mental incompetence
• Delirium secondary to medical illness
• PTSD or DID due to general medical or neurological illness
• History of neurological conditions that may cause significant psychiatric symptomatology (e.g., dementia)
• Any contraindication to MR scans, including claustrophobia, pregnancy, metal implants, etc.
• Current alcohol or substance dependence or abuse (within the last month)
• A history of schizophrenia or other psychotic disorder
• History of head injury or loss of consciousness for longer than 5 min (including concussion)

The study will enroll up to 90 female patients with either DID or PTSD ages 18-89. We will also recruit up to 60 control subjects matched for demographics (age, race, gender).