Neurodevelopmental origins of abnormal cortical morphology in dissociative identity disorder

Abstract

Objective To examine the two constitutes of cortical volume (CV), that is, cortical thickness (CT) and surface area (SA), in individuals with dissociative identity disorder (DID) with the view of gaining important novel insights into the underlying neurobiological mechanisms mediating DID. Methods This study included 32 female patients with DID and 43 matched healthy controls. Between‐group differences in CV, thickness, and SA, the degree of spatial overlap between differences in CT and SA, and their relative contribution to differences in regional CV were assessed using a novel spatially unbiased vertex‐wise approach. Whole‐brain correlation analyses were performed between measures of cortical anatomy and dissociative symptoms and traumatization. Results Individuals with DID differed from controls in CV, CT, and SA, with significantly decreased CT in the insula, anterior cingulate, and parietal regions and reduced cortical SA in temporal and orbitofrontal cortices. Abnormalities in CT and SA shared only about 3% of all significantly different cerebral surface locations and involved distinct contributions to the abnormality of CV in DID. Significant negative associations between abnormal brain morphology (SA and CV) and dissociative symptoms and early childhood traumatization (0 and 3 years of age) were found. Conclusions In DID, neuroanatomical areas with decreased CT and SA are in different locations in the brain. As CT and SA have distinct genetic and developmental origins, our findings may indicate that different neurobiological mechanisms and environmental factors impact on cortical morphology in DID, such as early childhood traumatization.

Aiding the diagnosis of dissociative identity disorder: pattern recognition study of brain biomarkers

“…28 Traumatic experiences were measured with the Traumatic Experience Checklist. 29 As expected and previously reported, 19 psychoform and somatoform dissociative symptoms and depersonalisation scores were significantly higher in the DID group as compared with healthy controls (all P-values <0.001). Individuals with DID also scored significantly higher compared with the controls for traumatic experiences (all P-values <0.001) on all five adverse life event categories, namely emotional neglect, emotional abuse, physical abuse, sexual abuse and sexual harassment (see Supplementary Table 1).…”

“…The DID and healthy control group were carefully matched for demographics including age, gender (all female), years of education and Western European ancestry. As previously shown, 19 we did not find any significant differences between patients and healthy controls with respect to age or education (see Supplementary Table 1 available at ). As part of the inclusion criteria, it was confirmed that all healthy controls were free of medication and psychiatric disorders.…”

“…Magnetic resonance imaging (MRI) data from 75 participants were obtained in the Netherlands in the University Medical Centre in Groningen (UMCG) and the Amsterdam Medical Centre (AMC), and in Switzerland at the University Hospital in Zurich. Details of these two samples have previously been published elsewhere: Chalavi et al 17 , 18 (Dutch sample), Schlumpf et al 12 , 13 (Swiss/German sample) and Reinders et al 19 (combined). All participants gave informed written consent in accordance with the Declaration of Helsinki and as dictated by ethics approval which was obtained from the Medical Ethical Committees of UMCG (Reference number: METC2008.211) and the AMC (Reference number: MEC09/155), and by the cantonal ethical commission of Zurich (Kantonale Ethikkommission Zürich; reference number: E-13/2008).…”

“…11,17,18 Early life stressors may have long-lasting detrimental effects on neurobiology due to altered stress reactivity following childhood trauma. 19 Earlier neuroanatomical studies in DID have found a smaller hippocampal volume, which seems to be the result of exposure to stress hormones due to antecedent traumatisation. Although it is currently unknown how early traumatisation affects the development of the brain, 19 it is not surprising that long-lasting trauma results in widespread patterns of affected grey and white matter brain regions.…”

Psychotic-Like Symptoms and the Temporal Lobe in Trauma-Related Disorders: Diagnosis, Treatment, and Assessment of Potential Malingering

“…Studies of patients with DID and comorbid PTSD reveal decreased temporal lobe cortical volume and cortical surface area compared to healthy controls. 115,116 For example, an MRI study of 15 female patients with DID revealed a 19.2% decrease in hippocampal volume and a 31.6% decrease in amygdala volume compared to controls. 117 Case reports, along with small SPECT studies of patients with DID, have demonstrated consistently that compared to healthy controls and DID simulators, patients with DID show increased perfusion in the left temporal lobe and that temporal perfusion increases while in a dissociated self-state.…”