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Objectives: Noninvasive brain stimulation (NIBS) has been shown to effectively alleviate negative and positive symptoms in patients with schizophrenia. However, its impact on depressive symptoms and general psychopathology symptoms (GPSs), which are crucial for functional outcomes, remains uncertain. We aimed to compare the efficacy of various NIBS interventions in treating depressive symptoms and GPSs. Methods: We conducted a comprehensive search of multiple databases and performed a meta-analysis to evaluate the efficacy of NIBS in treating depressive symptoms and GPSs in schizophrenia. The effect sizes of NIBS for depression symptoms and GPSs were estimated using standard mean differences (SMDs) with 95% confidence intervals (CIs). Subgroup analyses were employed to examine potential influencing factors on the pooled SMD of NIBS for GPSs. Results: Our search yielded 35 randomized controlled trials involving 1715 individuals diagnosed with schizophrenia. The protocol of this systematic review was registered with INPLASY (protocol ID: INPLASY202320082). Neither repetitive transcranial magnetic stimulation (rTMS) nor transcranial direct current stimulation (tDCS) demonstrated significant improvements in depressive symptoms compared to sham controls. NIBS exhibited a small-to-moderate effect size for GPSs, with a pooled SMD of –0.2956 (95% CI: –0.459 to –0.132) and a heterogeneity (I2) of 58.9% (95% CI: 41.5% to 71.1%; p < 0.01) based on a random-effects model. Subgroup analyses of different types of NIBS, different frequencies of rTMS, and different stimulation sites of rTMS revealed no significant differences. Only sex had a significant influence on the effect size of NIBS for general psychopathology symptoms (p < 0.05). However, rTMS might be superior to tDCS, and high-frequency rTMS outperformed low-frequency rTMS in treating GPSs. Conclusions: We found a small-to-moderate effect size of NIBS in alleviating GPSs in patients with schizophrenia. Both rTMS and tDCS were more effective than sham stimulation in reducing GPSs in schizophrenia. The frequency used was associated with rTMS efficacy for GPSs.

Introduction: Premonitory urge (PU) is an aversive bodily sensation that signals the onset of tic disorder.To our knowledge, PU typically precedes the appearance of tic symptoms, and both age and tic severity are correlated with PU. However, inconsistent findings have also been reported. Hence, we conducted a meta-analysis to examine the relationship among premonitory symptoms, patient age and the severity of tic symptoms, as well as to summarize the research on the neural underpinnings of PU in Tourette syndrome (TS). Methods: We conducted a literature search of relevant studies published between December 2005 and April 2022 using databases such as PubMed, Elsevier, PsycINFO, and Web of Science. Our analysis was carried out using R software with the assistance of the “meta” and “metafor” packages. Results: Our meta-analysis included 22 studies with a total of 1236 tic disorder patients. The mean Premonitory Urge for Tics Scale (PUTS) score was 20.17, with a 95% confidence interval of [18.14, 21.68]. Through meta-regression, we found that age and tic severity play important moderating roles in PU severity (p < 0.0001). Neuroimaging studies suggest that PU is related to the insula, prefrontal cortex (PFC), anterior cingulate cortex (ACC), and supplementary motor area (SMA), regardless of the structural or functional level. Conclusions: Our meta-analysis confirmed the positive relationship between the severity of tics and PU and identified age as a significant factor influencing PU. The neural mechanisms underlying PU remain largely unknown, but evidence suggests that the insula, PFC, ACC, and SMA are related regions.

Repetitive transcranial megnetic stimulation (rTMS) has been widely used in patients with psychiatric disorders. Previous studies revealed good efficacy of rTMS for patients with obsession-compulsive disorder (OCD) and Tic disorder (TD). OCD and TD are closely related and considered to etiologically overlap. Patients with the co-occurrence of OCD and TD are often identified. Therefore, we conducted a quick review of rTMS for the treatment of these two diseases to compare the similarities and differences of rTMS for OCD and TD, which might provide an indication for the treatment of the co-occurrence of OCD and TD. We searched articles published in PubMed, Wanfang, and Web of Science from January 2001 to January 2022. Both inclusion criteria and exclusion criteria were developed to identify the relevant included studies. Data on the frequency, target area, sample size, and number of males, especially the rTMS treatment procedure or parameters, were extracted in the included studies. We included 26 studies on OCD and 12 studies on TD in this quick review. A total of 996 participants were included. Based on the review of the included studies, lowfrequency rTMS might be used more than high-frequency rTMS, and the supplementary motor area (SMA) might show better efficacy than the dorsolateral prefrontal cortex (DLPFC) in OCD. For patients with TD, low-frequency rTMS located in the SMA might show good efficacy both in OCD and TD. Our quick review elaborated the treatment efficacy of rTMS for both patients with OCD and those with TD. It seems that the SMA is an important target choice for both OCD and TD patients. Low-frequency rTMS might be used more than high-frequency rTMS in both OCD and TD patients. In future studies, we should explore more about the efficacy of rTMS for patients with co-occurring OCD and TD, especially for the efficacy of targeted SMA with low frequency.

Background: Exposure and response prevention (ERP) is a form of cognitive behavioral therapy that can effectively relieve obsessive-compulsive symptoms and tic symptoms in patients with obsessive-compulsive disorder (OCD) and Tourette syndrome (TS). However, the effect size of ERP-based therapy is still unclear. Methods: In this study, we performed a meta-analysis to identify the efficacy of ERP-based therapy for individuals with OCD and TS. The standard mean difference (SMD) with a 95% confidence interval (CI) was calculated to assess the effect size of the efficacy for ERP-based therapy. We used subgroup and meta-regression analyses to explore the heterogeneity of the pooled SMD of ERP-based therapy for OCD. We also summarized the neuroimaging studies for ERP-based therapy for OCD. This meta-analysis was registered within the International Platform of Registered Systematic Review and Meta-analysis Protocols (number: INPLASY2021120112). Results: A total of 18 studies including a total of 1057 patients with OCD and 3 studies including 267 with TS/chronic tic disorder were identified. We did not observe any indication of publication bias using Egger’s funnel plot (p = 0.41). We observed a small-to-medium effect size of ERP for both OCD (SMD = –0.27, 95% CI: –0.53 to –0.01) and TS/chronic tic disorder (SMD = –0.35, 95% CI: –0.59 to –0.1). We found no heterogeneity of ERP-based therapy for OCD between the ERP-based therapy subgroup and medicine subgroup in the subgroup analysis (p = 0.72). We found no heterogeneity of ERP-based therapy for OCD between the child subgroup and adult subgroup in the subgroup analysis (p = 0.37). We used meta-regression analysis to identify the heterogeneity of ERP-based therapy for OCD and found that the sessions of therapy and publication year did not account for any significant heterogeneity (p > 0.05). The neurological mechanism of EPR-based therapy is unclear, but it may lie in changes in the prefrontal cortex and anterior cingulate cortex. Conclusions: In conclusion, we found that ERP-based therapy is effective for patients with OCD and TS/chronic tic disorder. We suggest a combination with other therapies and the development of online ERP services that might prove a promising new direction for healthcare providers.