Connectivity alterations
Results showed the rCEN was “most impacted” by pathological dissociation, with 39 clusters linked to connectivity alterations.
Ten clusters within tDN exhibited within-network hyperconnectivity related to dissociation but only of the depersonalization/derealization subtype.
Eight clusters within cSN were linked to dissociation – specifically, within-network hyperconnectivity and decreased connectivity between regions in rCEN with cSN, with “no significant unique contributions of dissociation subtypes,” the researchers report.
“Depersonalization and derealization symptoms were associated with increased communication between a brain network involved in reasoning, attention, inhibition, and working memory and a brain region implicated in out-of-body experiences. This may, in part, contribute to depersonalization/derealization feelings of detachment, strangeness or unreality experienced with your body and surroundings,” Dr. Lebois said.
“In contrast, partially dissociated intrusion symptoms central to DID were linked to increased communication between a brain network involved in autobiographical memory and your sense of self and a brain network involved in reasoning, attention, inhibition, and working memory,” she added.
She noted that this matches how patients with DID describe their mental experiences: as sometimes feeling as if they lost a sense of ownership over their own thoughts and feelings, which can “intrude into their mental landscape.”
In the future, Dr. Lebois hopes that “we may be able to monitor dissociative brain signatures during psychotherapy to help assess recovery or relapse, or we could target brain activity directly with neurofeedback or neuromodulatory techniques as a dissociation treatment in and of itself.”
A first step?
Commenting on the study, Richard Loewenstein, MD, adjunct professor, department of psychiatry, University of Maryland School of Medicine, Baltimore, called the paper a “first step in more sophisticated studies of pathological dissociation using cutting-edge concepts of brain connectivity, methodology based on naturalistic, dimensional symptoms categories, and innovative statistical methods.”
Dr. Loewenstein, who was not involved with the current study, added that there is an “oversimplified conflation of hallucinations and other symptoms of dissociation with psychosis.” So studies may “incorrectly relate phenomena such as racism-based trauma to psychosis, rather than pathological dissociation and racism-based PTSD,” he said.
He noted that the implications are “profound, as pathological dissociation is not treatable with antipsychotic medications and requires treatment with psychotherapy specifically targeting symptoms of pathological dissociation.”
The study was funded by the Julia Kasparian Fund for Neuroscience Research and the National Institute of Mental Health. Dr. Lebois reported unpaid membership on the Scientific Committee for the International Society for the Study of Trauma and Dissociation, grant support from the NIMH and the Julia Kasparian Fund for Neuroscience Research, and spousal IP payments from Vanderbilt University for technology licensed to Acadia Pharmaceuticals unrelated to the present work. The other investigators’ disclosures are listed in the original paper. Dr. Loewenstein has disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.