Whole-brain gray matter volume abnormalities in patients with generalized anxiety disorder

Abstract

Patients with generalized anxiety disorder (GAD) experience psychological distress because of excessive and uncontrollable anxiety in everyday life. Only a few morphological studies have so far focused on specific brain regions of interest as well as the gray matter volume changes in GAD patients. This study evaluated gray matter volume alterations in whole-brain areas between GAD patients and healthy controls, and sex differences between the specific brain areas with significant volume changes in GAD patients using voxel-based morphometry. Twenty-two patients with GAD (13 men and nine women), who were diagnosed using the DSM-IV-TR, and 22 age-matched healthy controls (13 men and nine women) participated in this study. The high-resolution MRI data were processed using voxel-based morphometry analysis on the basis of diffeomorphic anatomical registration through an exponentiated Lie algebra algorithm in Statistical Parametric Mapping 8. There was no significant difference in the total intracranial volume between GAD patients and controls, but a significant difference was observed between sexes (P<0.05). Patients with GAD showed significant volume reductions in the hippocampus, midbrain, thalamus, insula, and superior temporal gyrus compared with the controls. As for the sex comparison, female patients showed a significant increase in the volume of the dorsolateral prefrontal cortex relative to male patients. Also, the volume of the dorsolateral prefrontal cortex in female patients was correlated positively with the Hamilton Anxiety Rating Scale score (γ=0.68, P=0.04). The specific morphological variations in patient with GAD will be helpful to understand the neural mechanism associated with a symptom of GAD. Furthermore, the findings would be valuable for the diagnostic accuracy of GAD using morphometric MRI analysis.

Gray and white matter volume abnormalities in generalized anxiety disorder by categorical and dimensional characterization

“…These were also found for the dimensional approach to intolerance of uncertainty. While largely neglected in GAD research so far, structural alterations in the temporal gyri have been repeatedly reported in the GAD literature (De Bellis et al, 2002; Moon et al, 2014; Strawn et al, 2014). Nonclinical studies have related the temporal poles to a number of tasks including affective face processing and empathy (Olson et al, 2007; Jankowiak-Siuda et al, 2011), but more precise conclusions should not be drawn without more replication and inclusion of task-based investigations in GAD.…”

“…Several studies relied on a region-of-interest (ROI) approach, with different studies targeting different ROIs, limiting the chance for consistent findings. Only four studies used whole-brain approaches to assess GM volume in GAD (Schienle et al, 2011; Liao et al, 2013; Strawn et al, 2013; Moon et al, 2014), with two of these studies investigating adolescents (Liao et al, 2013; Strawn et al, 2013). The remaining two studies in adults did not report comparable findings.…”

“…Among the regions more frequently investigated for structural changes in GAD, only higher GM volumes in the amygdala (Etkin et al, 2009; Schienle et al, 2011) and lower GM volumes in the hippocampus (Abdallah et al, 2013; Moon et al, 2014) have been successfully replicated. However, several other areas have not been investigated sufficiently, although they were prominently included in functional studies on GAD.…”

Cerebral gray matter volume variation in female-to-male transsexuals

“…The brain MR images were preprocessed using an optimized protocol described in a previous study [12]. MR images were processed to nonuniformity correction to remove smoothly varying modulations of image intensities related to inhomogeneity in the magnetic field.…”

Working memory dysfunction associated with brain functional deficits and cellular metabolic changes in patients with generalized anxiety disorder

“…Recent studies (Moon et al, 2014;Moon et al, 2015a) reported that severe anxiety symptoms lead to emotional disorders including unsuppressed anger and low frustration tolerance, and/or cognitive disorders including low attention and memory deficits. The diagnosis of GAD relies on traditional evaluation methods based on clinical questionnaires (Rickels et al, 2002).…”