A meta-analytic approach to mapping co-occurrent grey matter volume increases and decreases in psychiatric disorders

Abstract

Numerous studies have investigated gray matter (GM) volume changes in diverse patient groups.Reports of disorder-related GM reductions are common in such work, but many studies also report evidence for GM volume increases in patients. It is unclear whether these GM increases and decreases independent or related in some way. Here, we address this question using a novel meta-analytic network mapping approach. We used a coordinate-based meta-analysis of 64 voxel-based morphometry studies of psychiatric disorders to calculate the probability of finding a GM increase or decrease in one region given an observed change in the opposite direction in another region. Estimating this cooccurrence probability for every pair of brain regions allowed us to build a network of concurrent GM changes of opposing polarity. Our analysis revealed that disorder-related GM increases and decreases are not independent; instead, a GM change in one area is often statistically related to a change of opposite polarity in other areas, highlighting distributed yet coordinated changes in GM volume as a function of brain pathology. Most regions showing GM changes linked to an opposite change in a distal area were located in salience, executive-control and default mode networks, as well as the thalamus and basal ganglia. Moreover, pairs of regions showing coupled changes of opposite polarity were more likely to belong to different canonical networks than to the same one. Our results suggest that regional GM alterations in psychiatric disorders are often accompanied by opposing changes in distal regions that belong to distinct functional networks.

A co-alteration parceling of the cingulate cortex

“…A whole brain, transdiagnostic meta-analysis suggested a differential involvement of the two hemispheres, the right one appearing to be more relevant for a MCN of decreases, while the left one for increases. Also, the interaction between the two forms of GM alteration in psychiatric disorders seemed to be more concentrated in the left hemisphere (Mancuso et al 2020). Despite the major involvement of the left cingulate cortex, in the present work the results of the clustering procedure were mostly symmetrical between the hemispheres (Fig.…”

Interhemispheric co-alteration of brain homotopic regions

“…First, the hubs of long-distance co-alteration of a transdiagnostic network of anatomical decreases were particularly located in certain regions of the left hemisphere, such as the dorsolateral prefrontal cortex and the sensorimotor cortex, while those of the network of increases were found in the homotopic areas of the opposite hemisphere (Cauda et al 2020). Secondly, calculating a network of interdependence between VBM decreases and increases of psychiatric disorders, we observed that its hubs were especially located in the left hemisphere, thus suggesting a left hemispheric dominance on the mechanisms of anatomical compensation (Mancuso et al 2020).…”

Reconsidering brain tissue changes as a mechanistic focus for early intervention in psychiatry

“…In particular, these co-alterations often involved reduced grey matter in the task-negative default-mode network (which is often observed to be "deactivated" during externally focused tasks in functional MRI studies) while concurrent increase occurred in task-positive subcortical and cognitive control regions. 26 Taken together, these findings indicate that the phenomenon commonly considered to be neuroprogression may instead be a well-coordinated compensatory process operating across various psychiatric disorders.…”

“…Infranormal deviations in thickness are more common in medial prefrontal, insula and lateral temporal regions (but in only 15%-20% of patients), whereas supra-normal changes are more common in occipital and paracentral regions (affecting 3% of patients), indicating distributed changes that lack regional specificity. 25 Furthermore, in a recent detailed appraisal of this issue of grey matter increase using a meta-analytical network mapping approach, Mancuso and colleagues 26 concluded that whenever grey matter reduction occurs in one brain region, concurrent grey matter increase occurs in other brain regions J Psychiatry Neurosci 2020;45(6) across various psychiatric disorders. Interestingly, such grey matter changes of opposite polarity occurred in distinct functional networks.…”