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Background and Aim: Although Repetitive Transcranial Magnetic Stimulation (rTMS) is a promising new noninvasive brain stimulation therapy, its underlying mechanisms of action remain unknown. OCD patients exhibit impaired response control and attention shifting, which is linked to some brain areas such as anterior cingulate cortex and basal ganglia. OCD patients also display altered neurometabolic concentrations in cortical cortical-striatal-thalamic-cortical (CSTC). In this study, we aimed to elucidate efficacy of rTMS treatment in alleviating related symptoms and pregenual anterior cingulate cortex (pACC) neurometabolites., Methods: OCD patients were randomly divided into either drug (n = 23) or drug + rTMS (n = 29) groups, and those in the latter group subjected to 4-week rTMS treatment. All participants were visited twice, at baseline and follow-up after four weeks. During both visits, all patients were subjected to 1H-MRS, then Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Global Assessment Function (GAF) used to assess severity of obsessive-compulsive symptoms. We also evaluated synchronous anxiety and depression by Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Hamilton Anxiety Scale (HAM-A) and Hamilton Depression Scale (HAM-D)., Results: After 4 weeks of treatment, patients in the Drug + rTMS group displayed significantly lower Y-BOCS (p = 0.038), BDI (p = 0.009), HAM-D (p = 0.013), HAM-A (p = 0.012) scores than their counterparts in the Drug group. Conversely, patients in the Drug + rTMS group had significantly higher tNAA concentrations (p = 0.030) than those in the Drug group. Notably, the Drug + rTMS group exhibited higher, but insignificant Glu (p = 0.055) and Glx (p = 0.068) concentrations compared to the Drug group. Partial correlation analysis revealed a significant negative correlation between post HAM-A scores and 4-week change of pACC glutamate levels in the Drug + rTMS group (r = -0.434, p = 0.02)., Conclusion: rTMS treatment is an efficacious treatment therapy for OCD, mainly by inducing changes in neurometabolites., Competing Interests: Conflict of interest No conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Objective: In obsessive-compulsive disorder (OCD), glutamatergic neurotransmission dysfunction played key roles in pathophysiology. The current research assessed changes of neurometabolites in the bilateral striatum of OCD patients receiving low-frequency repetitive transcranial magnetic stimulation (rTMS) using 1H proton magnetic resonance spectroscopy (1H-MRS)., Methods: 52 OCD patients were divided into rTMS treatment group (29) and the control group (medication only) (22). The levels of neurometabolites in the bilateral striatum of patients with OCD were measured using MRS before and after treatment. All participants were taking medication prior to the treatment and the process., Results: Following rTMS treatment, Yale-Brown Obsessive-Compulsive Scale (YBOCS) score was significantly decreased in the rTMS group compared with the control group. Glutamate (Glu) and glutamate and glutamine complexes (Glx) in the bilateral striatum of the rTMS treatment response group increased significantly with the improvement of OCD. Glu in the bilateral striatum and Glx in the right striatum were positively correlated with compulsion after the treatment., Conclusions: The physiopathological mechanism of OCD may be related to the glutamatergic dysfunction, and the low-frequency repetitive transcranial magnetic stimulation applied to the supplementary motor area can improve OCD symptoms by modulating glutamatergic levels in the bilateral striatum of patients with OCD., Competing Interests: Conflict of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Background: Physical inactivity exacerbates poorer sleep quality, but potential underlying mechanisms of this association remain unknown. The present study aims to disentangle the pathways linking psychical activity to sleep quality through the serial mediation effect of anxiety and depression in a Chinese population., Methods: Data analyzed were from Guangdong Sleep and Psychosomatic Health Survey, a cross-sectional population-based study with a representative sample of adult inhabitants aged 18-85 years living in Guangdong province, China. A total of 13,768 participants were included with the response rate of 80.4%. Singe and serial mediation analyses were conducted to examine whether anxiety and depression mediated the relationship between physical activity and sleep quality, independently and jointly., Results: Both direct and indirect effects of physical activity on sleep quality were found. As predicted, anxiety and depression mediated the relationship between physical activity and sleep quality (B Anxiety  = -0.17, 95% bootstrap CI: -0.20 to -0.15; B Depression = -0.25, 95% bootstrap CI: -0.28 to -0.21), respectively. In addition, serial mediation analyses indicated that the association of physical activity and sleep quality is mediated by anxiety and depression in a sequential manner (B = -0.13, 95% bootstrap CI: -0.15 to -0.11)., Limitations: The primary limitation of the study is the cross-sectional design, which limits the causal inference ability., Conclusions: These findings highlight the role of anxiety and depression as serial mediators of the relationship between physical activity and sleep quality. Thus, exercise-based programs focusing on improving sleep could benefit from a multi-faceted approach therapeutically targeting psychiatric disorders., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background: Obsessive Compulsive Disorder (OCD) is characterized by hyperactivity in a network of forebrain structures, including the anterior cingulate cortex (ACC). Convergent evidence suggests that glutamatergic dysfunction may contribute to the disorder. Skin picking disorder (SPD) was listed as one of the obsessive-compulsive and related disorders, which is often comorbid with OCD and share overlapping phenomenology and pathophysiology. However, potential confounding effects between the two diagnostic effects on neurotransmitter levels remain largely unexamined., Methods: We examined the pregenual anterior cingulate cortex (pACC) glutamate and other neurochemicals in 62 subjects using a single-voxel acquisition 1H MRS at 3Tesla; of these, 47 subjects yielded usable measurements of both glutamate and glutamine and were included in the analysis (17 medicated with OCD alone, 13 medicated with comorbid OCD + SPD, 17 healthy control)., Results: OCD with comorbid SPD showed significantly lower pACC glutamate than in patients without SPD (p = 0.001) or control subjects (p = 0.035). OCD without SPD subjects showed pACC glutamate levels indistinguishable from controls (p = 0.501). In the OCD with SPD subjects, glutamate was correlated with Y-BOCS total score in female patients (n = 9, r = 0.69, p = 0.041)., Limitations: The main limitation of the study was the cross-sectional data. Our patients were on SSRI medication which may have modified the effect of SPD and OCD interaction on glutamate activity., Conclusion: Our results suggest that alterations of the glutamatergic system may play an important role in the pathophysiology of a subgroup of OCD and reduced pACC glutamate may be a biomarker of a distinct subset of OCD patients., Competing Interests: Declaration of Competing Interest All authors report no biomedical financial interests or potential conflicts of interest., (Copyright © 2020. Published by Elsevier B.V.)

Background: Repetitive transcranial magnetic stimulation (rTMS) is an effective treatment for treatment-resistant depression (TRD), but its therapeutic mechanisms are unclear. White matter abnormalities are thought to cause network dysfunction underlying TRD. Diffusion tensor imaging (DTI) is an ideal tool for examining neural connections and the integrity of white matter. Few studies have used DTI to investigate the impact of rTMS on alterations of whiter matter in TRD., Method: 30 young treatment-resistant unipolar depression patients (19 males and 11 females) were enrolled in a double-blind, randomized high-frequency (15 Hz) rTMS treatment study. Seventeen patients were treated with real stimulation, and 13 were treated with sham stimulation. White-matter fractional anisotropy (FA) was evaluated using voxel-based analysis (VBA) of FA maps derived from DTI before and after treatment. Twenty-five age- and gender-matched subjects were examined as a control group., Results: In an exploratory VBA method, clusters of fifty voxels or greater that survived a family-wise error (FWE)-corrected threshold of p<0.05 were considered significant. The results revealed significantly reduced FA in the left middle frontal gyrus, with peak coordinates [-18 46 -14] in TRD patients. This reduced FA was significantly improved after active rTMS treatment, but not sham stimulation. FA increases were correlated with decreased depressive symptoms., Limitations: This study requires replication and further clarification in a larger patient population, and optimization of stimulation locations and methods., Conclusions: These results suggest that the efficacy of rTMS on TRD is related to increased white-matter FA in the left middle frontal gyrus., (Copyright © 2011 Elsevier B.V. All rights reserved.)