16/05/2021 Proofs of DID

https://www.researchgate.net/publication/271474221_Similar_cortical_but_not_subcortical_gray_matter_abnormalities_in_women_with_posttraumatic_stress_disorder_with_versus_without_dissociative_identity_disorder

Similar cortical but not subcortical gray matter abnormalities in women with posttraumatic stress disorder with versus without dissociative identity disorder

This research is very interesting!

It dates from 2015.

She compared MRI images of the brains of 65 people. 17 people with dissociative identity disorder (DID), 16 people with post traumatic stress disorder (PTSD) and 32 "healthy" people (without a psychiatric problem).

All participants conducted interviews using different diagnostic scales to determine their level of dissociation and the presence or absence of post-traumatic stress disorder in them: SCID-D, SDQ-20, SDQ-5, CDS, TEC, DES, CAPS. If you want to know more about these diagnostic scales, check out my previous post, each scale is linked.

What were the assumptions?

1. DID and PTSD have only a reduction in gray matter compared to controls in the frontal cortices (including cingulate, medial and lateral prefrontal, orbitofrontal, superior, middle and inferior frontal) (Geuze et al., 2008; Woodward et al. ., 2009; Nardo et al., 2013) and the island cortex (Kasai et al., 2008) as well as in the hippocampus and amygdala (Vermetten et al., 2006; Ehling et al., 2008)

2. Confirm the differences in gray matter abnormalities in the lower parietal cortex (Simeon et al., 2000; Reinders et al., 2003, 2006, 2012, 2014) and the dorsal striatum (Reinders et al., 2014).

3. And confirm that the volume sensitive regions of gray matter are sensitive to the effects of stress, such as the hippocampus, and would show negative correlations with the severity of traumatic life events. In addition, correlations with the severity of dissociative symptoms were present in the parietal cortices and striatum.

Results:

• Cortical volume:

1. DInd PTSD compared to healthy controls: cortical volume was significantly smaller. "had a significantly smaller cortical volume of the whole brain, both hemispheres, and frontal and temporal total and bilateral superparcels, and total and left insula".

2. No differences in volumes between DIand PTSD "there was no significant difference in cortical volumes in any of the superparcels between DID-PTSD and PTSD-only patients"

• Surface cortical:

1. Significant differences between all groups. "Significant differences between all groups (omnibus test) were found in the cortical surface of the frontal and insula superparcels."

• Cortical thickness:

1. The volumes of the hippocampus, putamen and pallidum differed significantly between the groups. “Patients with DID-PTSD had larger volumes of total and right pallidum compared to HC and larger volumes of total, left and right putamen and total and right pallidum than patients with PTSD alone. Paired t-tests showed significantly smaller total, left and right hippocampal volumes in DID-PTSD patients compared to HC. The PTSD-only and HC groups did not differ significantly on subcortical measures. "

• Clinical measures: DES, SDQ-20, CDS, TEC tests

1. In patient groups, significant intercorrelations were found between all measures. That is, the correlations between the predictors of dissociation were significant.

• Correlation analyzes between clinical measurements and MRI data:

1. The dissociative component was positively correlated with the volume of the bilateral putamen, right pallidum and right superior frontal cortex and was negatively correlated with the cortical volume of the left orbital pars, precentral and inferior parietal cortices. "The dissociative component was positively correlated with the volume of the bilateral putamen, the right pallidum and the right upper frontal cortex and was negatively correlated with the cortical volume of the left orbital pars, precentral and inferior parietal cortices"

2. The more traumas there are, the more it can be seen "the component of lifelong traumatic events was negatively correlated with the volume of the left orbital pars and the precentral cortices and bilateral hippocampus, and positively correlated with the volume of the right pallidum"

LH: left hemisphere

RH: right hemisphere

Images taken from the study. The color is correlated with the differentiation value ranging from purple to blue, green, yellow then red. The most significant differences in red.

Here are the areas (in colors) that differ for cortical volume between DID and healthy controls:

Here are the areas (in colors) that differ for cortical volume between DID and PTSD:

Here are the areas (in colors) that differ for cortical volume between PTSD and healthy controls: