Comparison of brain activity within the sensorimotor network between sports players and patients with somatic symptom disorder

Within- and across-network alterations in the default network and in visual networkpatients with somatic symptom disorder

BACKGROUND

Somatic symptom disorders (SSDs) are common medical disorders characterized by various biological, psychological, and social pathogenic factors. Little is known about the functional profiles associated with SSDs within and between brain networks.

METHODS

In this study, resting-state functional magnetic resonance imaging (fMRI) was assessed in 60 patients with SSD and 62 matched healthy controls (HCs). Independent component analysis (ICA) of 20 components was conducted and investigated for functional connectivity changes within and acrossnetworks between patients and controls. In addition, fractional amplitudes of low-frequency fluctuation (fALFF) were used to detect intensities of spontaneous functional activity in networks successfully separated by ICA.

RESULTS

The patients with SSD exhibited significantly increased functional connectivity (FC) in the left lingual gyruswithin thevisual network, and higher fALFF values in the cingulate cortex and precuneus within the default network. Furthermore, SSD patients showed significantly decreased FC between the default and visual networks.

CONCLUSION

SSD is associated with significant changes within thevisual network, and the defaultnetwork, and decreased FC between the default network and visual network, which may indicate an imbalance within and between networks. These decouplings are likely associated with impaired perceptual and self-conscious integration in those with the disease.

Efficacy of aripiprazole as adjunctive therapy in major depressive disorder with somatic symptoms: A randomized, double-blind, placebo-controlled trial with clinical and electroencephalography evidence

BACKGROUND

Somatic symptoms, which are common in major depressive disorder (MDD), are associated with a worse prognosis and increased health costs.

AIMS

This randomized, double-blind, placebo-controlled study evaluated the efficacy of aripiprazole augmentation in MDD patients with somatic symptoms.

METHODS

In all, 41 MDD patients with somatic symptoms completed the study. Participants who had been on a stable dose of antidepressants for at least 1 month were randomly assigned to receive an 8-week adjunctive treatment with either aripiprazole or placebo. The initiation dose of aripiprazole was 2 mg/day, which was later adjusted to 1-10 mg/day. The primary endpoint was the change in the Symptom Checklist-90-Revised-Somatization (SCL-90-R-SOM) score. We collected quantitative electroencephalogram data and performed spectral analyses to obtain the absolute power of frequency bands.

RESULTS/OUTCOMES

The aripiprazole group (n = 20; 2.98 ± 1.75 mg/day) showed a significant improvement in SCL-90-R-SOM scores compared to the placebo group (n = 21; F = 8.56, p = 0.006), without significant differences in changes in depression and anxiety symptoms. Compared to the control, the aripiprazole group showed a greater decrease in total alpha power (F = 7.03, p = 0.01). Changes in frontal alpha power were positively correlated with changes in SCL-90-R-SOM scores in the aripiprazole group (r = 0.53, p = 0.014).

CONCLUSIONS/INTERPRETATION

Aripiprazole adjunctive to antidepressants in patients with MDD and somatic symptoms improved somatic symptom severity without significant safety concerns, and this improvement correlated with a decrease in total and frontal alpha power.Trial Registration: https://cris.nih.go.kr; identifier: KCT0004607.

Significant Structural Alterations and Functional Connectivity Alterations of Cerebellar Gray Matter in Patients With Somatic Symptom Disorder

Objective

Recent studies have revealed a strong association between the cerebellum and psychiatric disorders. However, the structural changes in the cerebellar regions and functional connectivity (FC) patterns in patients with somatic symptom disorder (SSD) have not been elucidated.

Methods

Thirty-seven patients with SSD (29 drug-naive and 8 medicated patients) and 37 sex- and age-matched healthy controls (HCs) were recruited and underwent resting-state functional magnetic resonance imaging scans. The spatially unbiased infratentorial (SUIT) cerebellar atlas-based voxel-based morphometry was used to investigate the changes in cerebellar regional gray matter (GM). Seed-based FC was further computed to explore the pattern of abnormal FC across the whole brain. Correlations were calculated to investigate the relationship between cerebellar structural (and FC) changes and clinical characteristics.

Results

After controlling for age, sex, total intracranial volume, medication, and mean FD covariates, all patients with SSD had increased mean GM volume (GMV) in the posterior lobules of the cerebellum bilaterally when compared with HCs, specifically, in the bilateral cerebellar crura I and II. Patients with SSD showed significantly stronger FC between the right crura I and II and bilateral precuneus inferior parietal region, and postcentral gyrus, extending to the superior parietal lobe, cingulate gyrus, and the white matter subgyral. In addition to the two clusters, right lingual gyrus was also a surviving cluster with significantly higher FC. Partial correlation analysis revealed that the degree of regional GMV increases in the two significant clusters and the Hamilton Depression Scale (HAMD) score was negatively correlated. Moreover, the FC of right crura I and II with the left parietal lobe and right lingual gyrus were also negatively associated with the HAMD score.

Conclusions

SSD exhibited significant microstructural changes and changes in FC pattern in the posterior cerebellar lobe. These results shed new light on the psychological and neural substrates of SSD and may serve as a potential treatment target for SSD based on the cerebellar area.