Shared white matter alterations across emotional disorders: A voxel-based meta-analysis of fractional anisotropy

Abstract

BackgroundWhite matter (WM) integrity may represent a shared biomarker for emotional disorders (ED). Aims: To identify transdiagnostic biomarkers of reduced WM by meta-analysis of findings across multiple EDs.MethodWeb of Science was searched systematically for studies of whole brain analysis of fractional anisotropy (FA) in adults with major depressive disorder, bipolar disorder, social anxiety disorder, obsessive-compulsive disorder or posttraumatic stress disorder compared with a healthy control (HC) group. Peak MNI coordinates were extracted from 37 studies of voxel-based analysis (892 HC and 962 with ED) and meta-analyzed using seed-based d Mapping (SDM) Version 4.31. Separate meta-analyses were also conducted for each disorder.ResultsIn the transdiagnostic meta-analysis, reduced FA was identified in ED studies compared to HCs in the left inferior fronto-occipital fasciculus, forceps minor, uncinate fasciculus, anterior thalamic radiation, superior corona radiata, bilateral superior longitudinal fasciculi, and cerebellum. Disorder-specific meta-analyses revealed the OCD group had the most similarities in reduced FA to other EDs, with every cluster of reduced FA overlapping with at least one other diagnosis. The PTSD group was the most distinct, with no clusters of reduced FA overlapping with any other diagnosis. The BD group were the only disorder to show increased FA in any region, and showed a more bilateral pattern of WM changes, compared to the other groups which tended to demonstrate a left lateralized pattern of FA reductions.ConclusionsDistinct diagnostic categories of ED show commonalities in WM tracts with reduced FA when compared to HC, which links brain networks involved in cognitive and affective processing. This meta-analysis facilitates an increased understanding of the biological markers that are shared by these ED.

Incapacity to control emotion in major depression may arise from disrupted white matter integrity and OFC‐amygdala inhibition

“…Reduced FA in the patients may indicate impaired water diffusion along the left and right UF, suggesting impaired integrity of these fiber tracts. This finding is in line with previous studies, in which reduced FA in fronto‐temporal white matter tracts has been reported A recent meta‐analysis found that reduced FA in fronto‐temporal and fronto‐parietal white matter tracts was shared across emotional disorders . Adolescents with depression demonstrated reduced FA in bilateral UF, which has been suggested to be a predisposing risk factor for depression .…”

“…This finding is in line with previous studies, in which reduced FA in fronto-temporal white matter tracts has been reported 25 A recent meta-analysis found that reduced FA in fronto-temporal and fronto-parietal white matter tracts was shared across emotional disorders. 26 Adolescents with depression demonstrated reduced FA in bilateral UF, which has been suggested to be a predisposing risk factor for depression. 25 In adults, carrier of the BDNF with MDD also exhibited smaller FA in the UF.…”

Widespread higher fractional anisotropy associates to better cognitive functions in individuals at ultra‐high risk for psychosis

“…In addition, the left uncinate fasciculus has been associated with IQ, verbal and visual memory, executive function (Gurrera et al, 2007;Nakamura et al, 2005), and language functions in schizotypal personality disorder (Rodrigo et al, 2007). This would be in line with the results from a recent meta-analysis on WM-alterations across emotional disorders (affective and anxiety disorders), showing transdiagnostic communalities in WM-tracts, with the uncinate fasciculus contributing significantly (Jenkins et al, 2016). We speculate, if our results could reflect that a majority of the UHR-individuals were diagnosed with co-morbid affective and/or anxiety disorders.…”

Emerging depression in adolescence coincides with accelerated frontal cortical thinning

“…In follow‐up analyses, we found that specific lateral orbitofrontal and precentral regions showed the strongest relation between accelerated cortical thinning and depression symptomatology. Lateral orbitofrontal regions and their connections with, for example, the amygdala (Von Der Heide, Skipper, Klobusicky, & Olson, ) are thought to be important for regulating emotional arousal which is related to depressive symptomatology, such as flattened affect (Jenkins et al., ). Hence, earlier maturation of PFC regions may indicate excessive cognitive control over emotional tendencies; however, this remains speculative.…”