Task-related brain activation associated with violence in patients with schizophrenia: A meta-analysis.

This study investigates specific changes in brain function during cognitive and emotional tasks in patients with schizophrenia and a history of violence (VSCZ) compared with non-violent patients with schizophrenia and healthy controls. A comprehensive literature search was conducted at the Web of Science, Medline, and PubMed. Ten studies met the inclusion criteria. In which, eight studies compared brain activation between patients with VSCZ and non-violent patients with schizophrenia, and the former exhibited increased activation at the middle occipital gyrus and rectus compared with the latter. Seven studies compared brain activation between patients with VSCZ and controls, and the former exhibited increased activation at the anterior cingulate cortex, cerebellum VI region, lingual gyrus and fusiform. Subgroup analysis in five studies performing emotional tasks revealed that patients with VSCZ showed increased activation at the middle occipital gyrus compared with non-violent patients with schizophrenia. Our findings suggest that abnormal emotion perception and regulation significantly contribute to the increased risk of violence in patients with schizophrenia. Notably, the middle occipital gyrus and rectus emerge as key neurophysiological correlates associated with this phenomenon.

Neuropathological characteristics of abnormal white matter functional signaling in adolescents with major depression.

BACKGROUND: Major depression disorder (MDD) constitutes a significant mental health concern. Epidemiological surveys indicate that the lifetime prevalence of depression in adolescents is much higher than that in adults, with a corresponding increased risk of suicide. In studying brain dysfunction associated with MDD in adole-scents, research on brain white matter (WM) is sparse. Some researchers even mistakenly regard the signals generated by the WM as noise points. In fact, studies have shown that WM exhibits similar blood oxygen level-dependent signal fluctuations. The alterations in WM signals and their relationship with disease severity in adolescents with MDD remain unclear. AIM: To explore potential abnormalities in WM functional signals in adolescents with MDD. METHODS: This study involved 48 adolescent patients with MDD and 31 healthy controls (HC). All participants were assessed using the Patient Health Questionnaire-9 Scale and the mini international neuropsychiatric interview (MINI) suicide inventory. In addition, a Siemens Skyra 3.0T magnetic resonance scanner was used to obtain the subjects' image data. The DPABI software was utilized to calculate the WM signal of the fractional amplitude of low frequency fluctuations (fALFF) and regional homogeneity, followed by a two-sample t-test between the MDD and HC groups. Independent component analysis (ICA) was also used to evaluate the WM functional signal. Pearson's correlation was performed to assess the relationship between statistical test results and clinical scales. RESULTS: Compared to HC, individuals with MDD demonstrated a decrease in the fALFF of WM in the corpus callosum body, left posterior limb of the internal capsule, right superior corona radiata, and bilateral posterior corona radiata [P < 0.001, family-wise error (FWE) voxel correction]. The regional homogeneity of WM increased in the right posterior limb of internal capsule and left superior corona radiata, and decreased in the left superior longitudinal fasciculus (P < 0.001, FWE voxel correction). The ICA results of WM overlapped with those of regional homo-geneity. The fALFF of WM signal in the left posterior limb of the internal capsule was negatively correlated with the MINI suicide scale (P = 0.026, r = -0.32), and the right posterior corona radiata was also negatively correlated with the MINI suicide scale (P = 0.047, r = -0.288). CONCLUSION: Adolescents with MDD involves changes in WM functional signals, and these differences in brain regions may increase the risk of suicide.

Aberrant brain structure in patients with schizophrenia and violence: A meta-analysis.

Previous studies have indicated that schizophrenia is associated with an increased risk of violence, which may constitute a public health concern, leading to poor treatment outcomes and stigmatization of patients. Investigating brain structural features of violence in schizophrenia could help us understand its specific pathogenesis and find effective biomarkers. Our study aimed at identifying reliable brain structural changes associated with violence in patients with schizophrenia by conducting a meta-analysis and meta-regression of magnetic resonance imaging studies. Specific brain changes in patients with schizophrenia and violence (VSZ) were studied, compared with patients with schizophrenia and violence (VSZ), patients with non-violent schizophrenia (NVSZ), and individuals with a history of violence only and health controls. Primary outcomes revealed that there was no significant difference of gray matter volume between patients with VSZ and patient with NVSZ. Compared with controls, patients with VSZ exhibited decreased gray matter volume in the insula, the superior temporal gyrus (STG), the left inferior frontal gyrus, the left parahippocampus, and the right putamen. Compared with individuals with a history of violence only, patients with VSZ exhibited decreased volume in the right insula and the right STG. Meta-regression analysis revealed a negative correlation between the duration of schizophrenia and the volume of the right insula in patients with VSZ. These findings may suggest a shared neurobiological basis for both violence and psychiatric symptoms. The impaired frontotemporal-limbic network may serve as a neurobiological basis for higher prevalence of violent behaviour in patients with schizophrenia. However, it is important to note that these changes are not unique to patients with VSZ. Further investigation is needed to explore the neural mechanism that drive the interaction between violent behaviour and specific aggression-related dimensions of schizophrenia.

Molecular epidemiological characteristics of the virus in 96 children with acute diarrhea in Changdu of Tibet, China. / 西藏昌都地区96ä¾‹å„¿ç«¥æ€¥æ€§è ¹æ³»ç— æ¯’åˆ†å­æµè¡Œç— å­¦åˆ†æž.

OBJECTIVES: To study the molecular epidemiological characteristics of the virus in children with acute viral diarrhea in Changdu of Tibet, China. METHODS: Fecal specimens were collected from 96 children with acute diarrhea who visited the People's Hospital of Changdu, Tibet, from November 2018 to November 2020 and were tested for adenovirus, norovirus, astrovirus, sapovirus, and rotavirus. Gene sequencing was performed for the genotypes of these viruses. RESULTS: The overall positive rate of the five viruses was 39% (37/96), among which astrovirus had the highest positive rate of 17%, followed by norovirus (9%), rotavirus (8%), adenovirus (7%), and sapovirus (5%). There was no significant difference in the positive rate of the five viruses among different age groups (P>0.05). Only the positive rate of astrovirus was significantly different among the four seasons (P<0.05). For adenovirus, 6 children had F41 type and 1 had C2 type; for norovirus, 6 had GⅠ.3 type, 1 had GⅠ.7 type, 1 had GⅡ.3 type, and 2 had GⅡ.4 Sydney_2012 type; HAstrV-1 type was observed in all children with astrovirus infection; for sapovirus, 1 child each had sporadic GⅠ.2, GⅠ.6, and GⅡ.1 sapovirus and 2 children had unknown type; 6 children had rotavirus G9[P8]. CONCLUSIONS: Astrovirus and norovirus are important pathogens in children with acute diarrhea in Changdu, Tibet. The positive rate of adenovirus, norovirus, astrovirus, sapovirus, and rotavirus is not associated with age, and only the positive rate of astrovirus has obvious seasonality. F41 type is the dominant genotype of adenovirus; GⅠ.3 is the dominant genotype of norovirus; HAstrV-1 is the dominant genotype of astrovirus; sporadic GⅠ.2, GⅠ.6, and GⅡ.1 are the dominant genotypes of sapovirus; G9[P8] is the dominant genotype of rotavirus.

Aberrant pattern of cerebral blood flow in patients with major depressive disorder: A meta-analysis of arterial spin labelling studies.

BACKGROUND: Accumulating evidence has suggested that patients with major depressive disorder (MDD) could exhibit resting-state cerebral blood flow (CBF) abnormalities. However, findings across studies are controversial. METHODS: Our study aimed at identifying replicable CBF changes in MDD by conducting a case-control meta-analysis and meta-regression of arterial spin labelling studies using seed-based d mapping software. Fourteen studies encompassing 505 patients with MDD and 443 healthy controls were included. RESULTS: We found increased CBF in the inferior parietal lobule, the striatum, and the bilateral thalamus in all patients with MDD relative to healthy controls. While decreased CBF was observed in the inferior frontal gyrus, the insula, the middle occipital gyrus and the bilateral superior temporal gyrus in patients with MDD. Moreover, increased CBF of the bilateral thalamus was associated with more severe depressive symptoms in patients with MDD. The subgroup meta-analysis showed that patients with acute phase had increased CBF in the bilateral thalamus, and decreased CBF in the left middle occipital gyrus and the left middle frontal gyrus. Chronic patients had decreased CBF in the left insula, the right calcarine sulcus, the right inferior frontal gyrus, and the left parahippocampal gyrus. Patients with medication-free had increased CBF in the right anterior cingulate cortex/medial prefrontal cortex, and decreased CBF in the left middle occipital gyrus, the left inferior frontal gyrus, and the left precentral gyrus. CONCLUSIONS: These findings suggest an aberrant cerebral blood flow pattern of MDD involving the cortico-striatal-thalamic circuit, which may facilitate understanding of pathophysiology and suggest potential neural biomarkers for clinical assessment, monitoring and interventions of MDD. One important limitation is that eight recruited studies in our meta-analysis have recruited more males than females, which may have a selection bias of patients.

Altered brain structural and functional connectivity in schizotypy.

BACKGROUND: Schizotypy refers to schizophrenia-like traits below the clinical threshold in the general population. The pathological development of schizophrenia has been postulated to evolve from the initial coexistence of 'brain disconnection' and 'brain connectivity compensation' to 'brain connectivity decompensation'. METHODS: In this study, we examined the brain connectivity changes associated with schizotypy by combining brain white matter structural connectivity, static and dynamic functional connectivity analysis of diffusion tensor imaging data and resting-state functional magnetic resonance imaging data. A total of 87 participants with a high level of schizotypal traits and 122 control participants completed the experiment. Group differences in whole-brain white matter structural connectivity probability, static mean functional connectivity strength, dynamic functional connectivity variability and stability among 264 brain sub-regions of interests were investigated. RESULTS: We found that individuals with high schizotypy exhibited increased structural connectivity probability within the task control network and within the default mode network; increased variability and decreased stability of functional connectivity within the default mode network and between the auditory network and the subcortical network; and decreased static mean functional connectivity strength mainly associated with the sensorimotor network, the default mode network and the task control network. CONCLUSIONS: These findings highlight the specific changes in brain connectivity associated with schizotypy and indicate that both decompensatory and compensatory changes in structural connectivity within the default mode network and the task control network in the context of whole-brain functional disconnection may be an important neurobiological correlate in individuals with high schizotypy.

Co-occurrence of schizo-obsessive traits and its correlation with altered executive control network functional connectivity.

The prevalence of obsessive-compulsive symptoms (OCS) in schizophrenia patients is as around 30%. Evidence suggested that mild OCS could reduce symptoms of schizophrenia, supporting the presence of compensatory functions. However, severe OCS could aggravate various impairments in schizophrenia patients, supporting the "double jeopardy hypothesis". Patients with schizo-obsessive comorbidity, schizophrenia patients and obsessive-compulsive disorder patients have been found to have similarities in executive dysfunctions and altered resting-state functional connectivity within the executive control network (ECN). Executive functions could be associated with the ECN. However, little is known as to whether such overlap exists in the subclinical populations of individuals with schizo-obsessive traits (SOT), schizotypal individuals and individuals with high levels of obsessive-compulsive symptoms (OCS). In this study, we recruited 30 schizotypal individuals, 25 individuals with OCS, 29 individuals with SOT and 29 controls for a resting-state ECN-related functional connectivity (rsFC) and a go/shift/no-go task. We found that individuals with SOT exhibited increased rsFC within the ECN compared with controls, while schizotypal individuals exhibited the opposite. Individuals with OCS exhibited decreased rsFC within the ECN and between the ECN and the default mode network (DMN), relative to controls. No significant correlational results between altered rsFC related to the ECN with executive function performance were found after corrections for multiple comparisons in three subclinical groups. Our findings showed that individuals with SOT had increased rsFC within the ECN, while schizotypal individuals and individuals with OCS showed the opposite. Our findings provide evidence for possible neural substrates of subclinical comorbidity of OCS and schizotypy.

Distinct clinical manifestations of obsessive-compulsive disorder are associated with cortical thickness alteration.

BACKGROUND: Although brain structural changes have been reported in patients with obsessive-compulsive disorder (OCD), results from previous studies have been inconsistent. A growing number of studies have focused on obsessive beliefs and impulsivity which could be involved in the occurrence and maintenance of OCD symptoms. The present study aimed to examine whether there are distinct brain structural changes in patients with different OCD subgroups. METHODS: Eighty-nine patients with OCD and 42 healthy controls were recruited to undergo structural magnetic resonance imaging brain scan. OCD patients were classified into subgroups according to scores of the Obsessive Belief Questionnaire (OBQ-44) and the Barratt Impulsiveness Scale (BIS-11) using cluster analysis. Group comparisons in cortical thickness and subcortical volumes between all OCD patients and healthy controls, as well as between subgroups of OCD patients and healthy controls, were carried out. RESULTS: OCD patients with more obsessive beliefs and attentional impulsivity (OCD_OB_AT) had reduced cortical thickness at the inferior parietal gyrus, the superior and middle temporal gyrus and the insula compared with OCD patients with higher score on the non-planning impulsivity (OCD_NP, corrected p < 0.05). The whole group of OCD patients and both subgroups showed reduced cortical thickness at the superior parietal gyrus compared with controls (uncorrected p < 0.01, number of vertices > 100). CONCLUSION: Our results suggest that apart from distinct phenomenology, there are distinct neural correlates of different OCD subgroups based on obsessive beliefs and impulsivity. These neural correlates may have clinical significance and should be considered in future research.

Hub-connected functional connectivity within social brain network weakens the association with real-life social network in schizophrenia patients.

Hubs in the brain network are the regions with high centrality and are crucial in the network communication and information integration. Patients with schizophrenia (SCZ) exhibit wide range of abnormality in the hub regions and their connected functional connectivity (FC) at the whole-brain network level. Study of the hubs in the brain networks supporting complex social behavior (social brain network, SBN) would contribute to understand the social dysfunction in patients with SCZ. Forty-nine patients with SCZ and 27 healthy controls (HC) were recruited to undertake the resting-state magnetic resonance imaging scanning and completed a social network (SN) questionnaire. The resting-state SBN was constructed based on the automatic analysis results from the NeuroSynth. Our results showed that the left temporal lobe was the only hub of SBN, and its connected FCs strength was higher than the remaining FCs in both two groups. SCZ patients showed the lower association between the hub-connected FCs (compared to the FCs not connected to the hub regions) with the real-life SN characteristics. These results were replicated in another independent sample (30 SCZ and 28 HC). These preliminary findings suggested that the hub-connected FCs of SBN in SCZ patients exhibit the abnormality in predicting real-life SN characteristics.

Brain Functional and Structural Changes in Alzheimer's Disease With Sleep Disorders: A Systematic Review.

Introduction: Sleep disorders (SLD) are supposed to be associated with increased risk and development of Alzheimer's disease (AD), and patients with AD are more likely to show SLD. However, neurobiological performance of patients with both AD and SLD in previous studies is inconsistent, and identifying specific patterns of the brain functional network and structural characteristics in this kind of comorbidity is warranted for understanding how AD and SLD symptoms interact with each other as well as finding effective clinical intervention. Thus, the aims of this systematic review were to summarize the relevant findings and their limitations and provide future research directions. Methods: A systematic search on brain functional and structural changes in patients with both AD and SLD was conducted from PubMed, Web of Science, and EMBASE databases. Results: Nine original articles published between 2009 and 2021 were included with a total of 328 patients with comorbid AD and SLD, 367 patients with only AD, and 294 healthy controls. One single-photon emission computed tomography study and one multislice spiral computed tomography perfusion imaging study investigated changes of cerebral blood flow; four structural magnetic resonance imaging (MRI) studies investigated brain structural changes, two of them used whole brain analysis, and another two used regions of interest; two resting-state functional MRI studies investigated brain functional changes, and one 2-deoxy-2-(18F)fluoro-d-glucose positron emission tomography (18F-FDG-PET) investigated 18F-FDG-PET uptake in patients with comorbid AD and SLD. Findings were inconsistent, ranging from default mode network to sensorimotor cortex, hippocampus, brain stem, and pineal gland, which may be due to different imaging techniques, measurements of sleep disorder and subtypes of AD and SLD. Conclusions: Our review provides a systematic summary and promising implication of specific neuroimaging dysfunction underlying co-occurrence of AD and SLD. However, limited and inconsistent findings still restrict its neurobiological explanation. Further studies should use unified standards and comprehensive brain indices to investigate the pathophysiological basis of interaction between AD and SLD symptoms in the development of the disease spectrums.

Neural mechanisms of prospection in individuals with schizotypal traits, autistic traits, or depressive symptoms.

Prospection refers to the ability to mentally construct future events, which is closely related to motivation and anhedonia. The neural underpinning of impaired prospection in psychiatric populations remains unclear. We recruited 34 individuals with autistic traits (AT), 27 individuals with schizotypal traits (ST), 31 individuals with depressive symptoms (DS), and 35 controls. Participants completed a prospection task while undergoing functional Magnetic Resonance Imaging (MRI). We found that regions of the "default mode network" including the medial frontal gyrus, the posterior cingulate cortex, the precuneus and the parahippocampus were activated; and regions of the "task-positive network" including the inferior parietal lobe, the inferior frontal gyrus and the precentral gyrus were deactivated during prospection in controls. Compared with controls, AT, ST, and DS showed comparable behavioral performance on prospection. However, reduced activation in anterior cingulate cortex and frontal gyrus was found in AT individuals relative to controls during prospection. ST individuals showed hyperactivation in the caudate relative to controls when processing positive emotion, while DS individuals and controls showed similar neural responses during prospection. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Social brain network correlates with real-life social network in individuals with schizophrenia and social anhedonia.

Social behaviour requires the brain to efficiently integrate multiple social processes, but it is not clear what neural substrates underlie general social behaviour. While psychosis patients and individuals with subclinical symptoms are characterized by social dysfunction, the neural mechanisms underlying social dysfunctions in schizophrenia spectrum disorders remains unclear. We first constructed a general social brain network (SBN) using resting-state functional connectivity (FC) with regions of interest based on the automatic meta-analysis results from NeuroSynth. We then examined the general SBN and its relationship with social network (SN) characteristics in 30 individuals with schizophrenia (SCZ) and 33 individuals with social anhedonia (SA). We found that patients with SCZ exhibited deficits in their SN, while SA individuals did not. SCZ patients showed decreased segregation and functional connectivity in their SBN, while SA individuals showed a reversed pattern with increased segregation and functional connectivity of their SBN. Sparse canonical correlation analysis showed that both SCZ patients and SA individuals exhibited reduced correlation between SBN and SN characteristics compared with their corresponding healthy control groups. These preliminary findings suggest that both SCZ and SA participants exhibit abnormality in segregation and functional connectivity within the general SBN and reduced correlation with SN characteristics. These findings could guide the development of non-pharmacological interventions for social dysfunction in SCZ spectrum disorders.

Altered activation and functional connectivity in individuals with social anhedonia when envisioning positive future episodes.

BACKGROUND: Anticipatory pleasure deficits are closely correlated with negative symptoms in schizophrenia, and may be found in both clinical and subclinical populations along the psychosis continuum. Prospection, which is an important component of anticipatory pleasure, is impaired in individuals with social anhedonia (SocAnh). In this study, we examined the neural correlates of envisioning positive future events in individuals with SocAnh. METHODS: Forty-nine individuals with SocAnh and 33 matched controls were recruited to undergo functional MRI scanning, during which they were instructed to simulate positive or neutral future episodes according to cue words. Two stages of prospection were distinguished: construction and elaboration. RESULTS: Reduced activation at the caudate and the precuneus when prospecting positive (v. neutral) future events was observed in individuals with SocAnh. Furthermore, compared with controls, increased functional connectivity between the caudate and the inferior occipital gyrus during positive (v. neutral) prospection was found in individuals with SocAnh. Both groups exhibited a similar pattern of brain activation for the construction v. elaboration contrast, regardless of the emotional context. CONCLUSIONS: Our results provide further evidence on the neural mechanism of anticipatory pleasure deficits in subclinical individuals with SocAnh and suggest that altered cortico-striatal circuit may play a role in anticipatory pleasure deficits in these individuals.

Neurological Soft Signs Are Associated With Altered Cerebellar-Cerebral Functional Connectivity in Schizophrenia.

Cerebellar dysfunction is associated with neurological soft signs (NSS), which is a promising endophenotype for schizophrenia spectrum disorders. However, the relationship between cerebellar-cerebral resting-state functional connectivity (rsFC) and NSS is largely unexplored. Moreover, both NSS and cerebellar-cerebral rsFC have been found to be correlated with negative symptoms of schizophrenia. Here, we investigated the correlations between NSS and cerebellar-cerebral rsFC, explored their relationship with negative symptoms in a main dataset, and validated the significant findings in a replication dataset. Both datasets comprised schizophrenia patients and healthy controls. In schizophrenia patients, we found positive correlations between NSS and rsFC of the cerebellum with the inferior frontal gyrus and the precuneus, and negative correlations between NSS and rsFC of the cerebellum with the inferior temporal gyrus. In healthy controls, NSS scores were positively correlated with rsFC of the cerebellum with the superior frontal gyrus and negatively correlated with rsFC between the cerebellum and the middle occipital gyrus. Cerebellar-prefrontal rsFC was also positively correlated with negative symptoms in schizophrenia patients. These findings were validated in the replication dataset. Our results suggest that the uncoupling of rsFC between the cerebellum and the cerebral cortex may underlie the expression of NSS in schizophrenia. NSS-related cerebellar-prefrontal rsFC may be a potential neural pathway for possible neural modulation to alleviate negative symptoms.

Neural Correlates of Audiovisual Temporal Binding Window in Individuals With Schizotypal and Autistic Traits: Evidence From Resting-State Functional Connectivity.

Temporal proximity is an important clue for multisensory integration. Previous evidence indicates that individuals with autism and schizophrenia are more likely to integrate multisensory inputs over a longer temporal binding window (TBW). However, whether such deficits in audiovisual temporal integration extend to subclinical populations with high schizotypal and autistic traits are unclear. Using audiovisual simultaneity judgment (SJ) tasks for nonspeech and speech stimuli, our results suggested that the width of the audiovisual TBW was not significantly correlated with self-reported schizotypal and autistic traits in a group of young adults. Functional magnetic resonance imaging (fMRI) resting-state activity was also acquired to explore the neural correlates underlying inter-individual variability of TBW width. Across the entire sample, stronger resting-state functional connectivity (rsFC) between the left superior temporal cortex and the left precuneus, and weaker rsFC between the left cerebellum and the right dorsal lateral prefrontal cortex were correlated with a narrower TBW for speech stimuli. Meanwhile, stronger rsFC between the left anterior superior temporal gyrus and the right inferior temporal gyrus was correlated with a wider audiovisual TBW for non-speech stimuli. The TBW-related rsFC was not affected by levels of subclinical traits. In conclusion, this study indicates that audiovisual temporal processing may not be affected by autistic and schizotypal traits and rsFC between brain regions responding to multisensory information and timing may account for the inter-individual difference in TBW width. LAY SUMMARY: Individuals with ASD and schizophrenia are more likely to perceive asynchronous auditory and visual events as occurring simultaneously even if they are well separated in time. We investigated whether similar difficulties in audiovisual temporal processing were present in subclinical populations with high autistic and schizotypal traits. We found that the ability to detect audiovisual asynchrony was not affected by different levels of autistic and schizotypal traits. We also found that connectivity of some brain regions engaging in multisensory and timing tasks might explain an individual's tendency to bind multisensory information within a wide or narrow time window. Autism Res 2021, 14: 668-680. © 2020 International Society for Autism Research and Wiley Periodicals LLC.

Visual short-term memory and attention: An investigation of familiarity and stroke count in Chinese characters.

Using Chinese characters, we investigated how stroke count and frequency of use influence attention and short-term memory (STM) encoding in Mainland Chinese speakers. To isolate specific components of attention we employed the Theory of Visual Attention (TVA), which allowed estimates of STM capacity, processing speed, and the threshold of visual perception. An analysis of TVA parameters revealed that familiarity affects both the memory capacity and processing speed of objects, whereas the threshold for visual perception remained unaffected. Interestingly, our results also indicate that modulation of attention is driven solely by familiarity with the characters, independent of the actual physical aspect of Chinese characters. We propose that mental categories and prior knowledge play a vital role in the processing of information in attention, as well as in how this information is stored and represented in visual STM. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Grey matter volume and structural covariance associated with schizotypy.

In this study, we applied brain grey matter volume and structural covariance methods on T1 weighted images to delineate potential structural brain changes in individuals with high schizotypy, who were defined as healthy individuals scoring in the top tenth percentile of the Schizotypal Personality Questionnaire (SPQ). Eighty-seven college students with high schizotypy and 122 controls were recruited in China. Differences in grey matter volume and volume covariance between the two groups, and correlations of grey matter volume with SPQ scores in the high schizotypy group were examined. We found that individuals with high schizotypy had decreased grey matter volume at the left medial superior frontal gyrus (medsFG) extending towards the superior frontal gyrus, decreased structural covariance within the right medsFG, between the right superior frontal gyrus (sFG), the right superior temporal gyrus and the right anterior insula; and increased structural covariance between the caudate and the right inferior temporal gyrus. Correlation analysis revealed that grey matter volume of the left middle temporal pole and the right sFG correlated positively with the SPQ total scores, volume of the bilateral cerebellum 9 sub-region correlated negatively with the SPQ cognitive-perceptual sub-scale scores, volume of the bilateral striatum correlated positively with the SPQ interpersonal sub-scale scores, and volume of the bilateral superior temporal pole correlated positively with the SPQ disorganization sub-scale scores in the high schizotypy group. These results highlight important grey matter structural changes in the medsFG in individuals with high schizotypy.

Altered default mode network functional connectivity in individuals with co-occurrence of schizotypy and obsessive-compulsive traits.

In this study, we examined differences in resting-state functional connectivity between sub-regions of the Default Mode Network (DMN) and whole brain voxels in 22 individuals with high schizo-obsessive traits (SOT), 30 with high schizotypal traits (SCT) alone, 20 with high obsessive-compulsive traits (OCT) alone and 30 with low trait scores (LT). We found that the SOT group showed the most reduced functional connectivity within the DMN compared with the other groups. The SOT group also showed increased connectivity between the DMN and the Salience Network, and between the DMN and the Auditory Network compared with the LT group. The SCT group exhibited increased connectivity between the DMN and the Salience Network, and between the DMN and the Executive Control Network (ECN) compared with the LT group. The OCT group exhibited decreased connectivity within the DMN, between the DMN and the Salience Network, and between the DMN and the ECN compared with the LT group. These findings highlight different changes in DMN-related functional connectivity associated with high SOT, SCT and OCT traits and may provide insight into the dysfunctional brain networks in the early stage of schizophrenia spectrum disorders.

Metabolite abnormalities in psychosis risk: A meta-analysis of proton magnetic resonance spectroscopy studies.

Accumulating evidence implicates that individuals at high-risk of psychosis have already exhibited pathophysiological changes in brain metabolites including glutamate, gamma-Aminobutyric Acid (GABA), N-Acetylaspartate (NAA), creatine (Cr), myo-inositol (MI) and choline (Cho). These changes may contribute to the development of schizophrenia and associate with psychotic genes. However, specific metabolic changes of brain sub-regions in individuals at risk have still been controversial. Thus, the current study aimed to investigate the brain metabolic changes including glutamate, Glx, GABA, GABA/Glx, NAA, Cr, MI and Cho levels in individuals at risk by conducting a case-control meta-analysis and meta-regression of proton magnetic resonance spectroscopy studies. Primary outcomes revealed that individuals at risk exhibited increased Cr levels at the rostral medial prefrontal cortex (rmPFC), decreased NAA and Cr levels at the thalamus, and increased MI levels at the dorsolateral prefrontal cortex. Sub-group analyses further indicated that individuals with clinical high-risk (CHR) exhibited increased Cr levels at the medial prefrontal cortex (mPFC) and decreased Glx levels at the thalamus, while individuals with genetic risk (siblings of psychiatric patients) exhibited significant increased Glx and MI levels at the mPFC. However, GABA, GABA/Glx and Cho levels showed no significant result. These findings suggest that the dysfunctional metabolites at the mPFC and the thalamus may be an essential neurobiological basis at the early stage of psychosis.