Mechanisms underlying dorsolateral prefrontal cortex contributions to cognitive dysfunction in schizophrenia

Effect of cariprazine on attention and quality of life in patients with predominant negative symptoms of schizophrenia: A post-hoc analysis

Background

Cariprazine, a potent dopamine D3-preferring D3/D2 receptor partial agonist, has demonstrated benefits on negative symptoms among patients with schizophrenia. Secondary endpoint and post-hoc analyses have also suggested a benefit of cariprazine on quality of life (QoL) and attention.

Methods

Data for this post-hoc analysis were pooled from two 6-week, placebo-controlled phase 3 trials evaluating cariprazine among patients with acute exacerbations of schizophrenia. One study included an aripiprazole active-control arm for assay sensitivity.Two populations were analyzed: pooled intention-to-treat (ITT) population (N = 1043), and the pooled subgroup with predominant negative symptoms (PNS, n = 215), as defined by the Positive and Negative Syndrome Scale (PANSS) subscale and item cut-off criteria at baseline. Analyses of interest were: Schizophrenia Quality of Life Scale Revision 4 (SQLS-R4) total score; Cognitive Drug Research (CDR) power of attention (PoA), and continuity of attention (CoA).

Results

Among study completers, cariprazine and aripiprazole were associated with significant SQLS-R4 improvements in the ITT and PNS populations. Differences in CDR-PoA scores were significant for cariprazine vs. placebo in the ITT and PNS populations, but not for aripiprazole in the ITT or PNS analyses. Differences in CDR-CoA scores were significant for cariprazine vs. placebo in the ITT and PNS analyses; and was significant for aripiprazole vs. placebo in the PNS analysis, but not in the ITT analysis.

Conclusions

This post-hoc analysis suggests that cariprazine may be associated with beneficial effects on measures of attention and QoL among patients with schizophrenia, and these effects could be more pronounced among individuals with PNS.

Characterization of Brain Abnormalities in Lactational Neurodevelopmental Poly I:C Rat Model of Schizophrenia and Depression Using Machine-Learning and Quantitative MRI

BACKGROUND

A recent neurodevelopmental rat model, utilizing lactational exposure to polyriboinosinic-polyribocytidilic acid (Poly I:C) leads to mimics of behavioral phenotypes resembling schizophrenia-like symptoms in male offspring and depression-like symptoms in female offspring.

PURPOSE

To identify mechanisms of neuronal abnormalities in lactational Poly I:C offspring using quantitative MRI (qMRI) tools.

STUDY TYPE

Prospective.

ANIMAL MODEL

Twenty Poly I:C rats and 20 healthy control rats, age 130 postnatal day.

FIELD STRENGTH/SEQUENCE

7 T. Multiflip-angle FLASH protocol for T1 mapping; multi-echo spin-echo T2-mapping protocol; echo planar imaging protocol for diffusion tensor imaging.

ASSESSMENT

Nursing dams were injected with the viral mimic Poly I:C or saline (control group). In adulthood, quantitative maps of T1, T2, proton density, and five diffusion metrics were generated for the offsprings. Seven regions of interest (ROIs) were segmented, followed by extracting 10 quantitative features for each ROI.

STATISTICAL TESTS

Random forest machine learning (ML) tool was employed to identify MRI markers of disease and classify Poly I:C rats from healthy controls based on quantitative features.

RESULTS

Poly I:C rats were identified from controls with an accuracy of 82.5 ± 25.9% for females and 85.0 ± 24.0% for males. Poly I:C females exhibited differences mainly in diffusion-derived parameters in the thalamus and the medial prefrontal cortex (MPFC), while males displayed changes primarily in diffusion-derived parameters in the corpus callosum and MPFC.

DATA CONCLUSION

qMRI shows potential for identifying sex-specific brain abnormalities in the Poly I:C model of neurodevelopmental disorders.

LEVEL OF EVIDENCE

NA TECHNICAL EFFICACY: Stage 2.

Kynurenine pathway dysregulation as a mechanistic link between cognitive impairment and brain damage: Implications for multiple sclerosis

Cognitive impairment is a core symptom of multiple sclerosis (MS), resulting from inflammation-related brain damage and brain network dysfunction. Inflammation also causes dysregulation of the kynurenine pathway, which is the primary route of tryptophan metabolism. Kynurenine pathway dysregulation is characterised by a shift in concentrations of tryptophan catabolites, also referred to as kynurenines. Some kynurenines have neurotoxic effects that partly resemble the molecular mechanisms of MS pathophysiology underpinning brain damage and brain network dysfunction. The kynurenine pathway may therefore qualify as a mechanistic link between systemic inflammation, brain damage, and cognitive impairment in MS. This perspective article (1) provides an overview of inflammation-related kynurenine pathway dysregulation and MS-relevant neuroimmune properties of kynurenines and (2) summarises the current evidence on associations between systemic kynurenines, imaging metrics of brain structure or related markers, and cognitive performance in populations that present with kynurenine pathway dysregulation and are prone to cognitive impairment. These findings are used to (3) set a research agenda for future studies aimed at clarifying the role of the kynurenine pathway in brain damage and cognitive impairment in MS.

Brain Structural and Functional Neuroimaging Features are Associated With Improved Auditory Hallucinations in Patients With Schizophrenia After Real-Time fMRI Neurofeedback

Auditory hallucinations (AHs) are debilitating and often treatment-resistant symptoms of schizophrenia (SZ). Real-time functional magnetic resonance imaging (fMRI) neurofeedback (NFB) is emerging as a flexible brain circuit-based tool for targeting AH via self-modulation of brain activity. A better understanding of what baseline characteristics predict NFB success will enhance its clinical utility. Previous work suggests that AH symptomology implicates measures across multiple modalities, including T1 structural MRI (sMRI), diffusion-weighted MRI (dMRI), and resting-state fMRI (rsfMRI). Specifically, AH severity and treatment response are associated with thinner superior temporal gyrus (STG), thinner dorsolateral prefrontal cortex (DLPFC), reduced white matter integrity in tracts connecting brain regions implicated in SZ symptomatology, increased within-default mode network (DMN) connectivity, and reduced DMN-DLPFC anticorrelation. In this study, we tested the individual and combined contributions of multimodal brain features for the prediction of AH change after NFB in adults (N = 25, 36.1 ± 10.0 years, 24% females) with SZ spectrum disorders (SZ or schizoaffective disorder) and frequent medication-resistant AH. Participants underwent a baseline MRI scan (including sMRI, dMRI, and rsfMRI) and were randomly assigned to receive NFB from their STG (n = 12, real condition) or NFB from their motor cortex (MC) (n = 13, sham condition). NFB success was operationalized as the improvement in AH severity after NFB. We found that higher baseline AH severity, greater STG thickness, decreased dorsal cingulum integrity, increased within-DMN resting-state functional connectivity, and increased DMN-DLPFC anticorrelation were each individually correlated with reduction in AH severity. However, in a combined regression model, DMN-DLPFC connectivity emerged as the only independent variable that explained the unique variance in AH change. These results suggest that a specific rsfMRI measure, namely DMN-DLPFC connectivity, may be a promising predictor of NFB success in reducing AH and support the precision medicine approach. Trial Registration: ClinicalTrials.gov identifier: NCT03504579.

The INO80E at 16p11.2 locus increases risk of schizophrenia in humans and induces schizophrenia-like phenotypes in mice

BACKGROUND

Chromosome 16p11.2 is one of the most significant loci in the genome-wide association studies (GWAS) of schizophrenia. Despite several integrative analyses and functional genomics studies having been carried out to identify possible risk genes, their impacts in the pathogenesis of schizophrenia remain to be fully characterized.

METHODS

We performed expression quantitative trait loci (eQTL) and summary-data-based Mendelian randomization (SMR) analyses to identify schizophrenia risk genes in the 16p11.2 GWAS locus. We constructed a murine model with dysregulated expression of risk gene in the medial prefrontal cortex (mPFC) using stereotaxic injection of adeno-associated virus (AAV), followed by behavioural assessments, dendritic spine analyses and RNA sequencing.

FINDINGS

We identified significant associations between elevated INO80E mRNA expression in the frontal cortex and risk of schizophrenia. The mice overexpressing Ino80e in mPFC (Ino80e-OE) exhibited schizophrenia-like behaviours, including increased anxiety behaviour, anhedonia, and impaired prepulse inhibition (PPI) when compared with control group. The neuronal sparse labelling assay showed that the density of stubby spines in the pyramidal neurons of mPFC was significantly increased in Ino80e-OE mice compared with control mice. Transcriptomic analysis in the mPFC revealed significant alterations in the mRNA levels of schizophrenia-related genes and processes related to synapses upon overexpressing Ino80e.

INTERPRETATION

Our results suggest that upregulation of the Ino80e gene in mPFC may induce schizophrenia-like behaviours in mice, further supporting the hypothesis that INO80E is an authentic risk gene.

FUNDING

This project received support from the National Key Research and Development Program of China, National Natural Science Foundation of China, Key Research and Development Projects of Hunan Provincial Science and Technology Department, Science and Technology Innovation team of Hunan Province, etc.

Network dynamics in post-stroke cognitive impairment: insights from effective connectivity analysis

This study investigates post-stroke cognitive impairment (PSCI) by utilizing spectral dynamic causal modeling (spDCM) to examine changes in effective connectivity (EC) within the default mode, executive control, dorsal attention, and salience networks. Forty-one PSCI patients and 41 demographically matched healthy controls underwent 3D-T1WI and resting-state functional magnetic resonance imaging on a 3.0T MRI. The study compared EC among eight representative regions of interest using spDCM and analyzed the correlation between altered EC and cognitive test scores. Subgroup analysis was conducted based on lesion location. The study found a significant increase in EC in the PSCI group, specifically from the posterior cingulate cortex (PCC) to the left and right dorsolateral prefrontal cortex (L_DLPFC and R_DLPFC, respectively), and from the right insula to R_DLPFC (p < 0.05). These changes were significantly negatively correlated with cognitive scores. Subgroup analysis showed increased executive control in PSCI patients with left anterior circulation lesions. Validation through low-order functional connectivity analysis indicated abnormalities dominated by large-scale intra- and inter-network functional connectivity increases in patients with PSCI. The study suggests an increase in effective connectivity between networks, particularly within the triple network model. The findings implicate the PCC and R_DLPFC in the pathophysiology of PSCI, shedding light on its cognitive implications. This study emphasizes the importance of understanding network changes in PSCI from various perspectives, enhancing our understanding of the neural mechanisms underlying PSCI, and establishing a foundation for future research.

Brain Structural Alterations Underlying Mood-Related Deficits in Schizophrenia

Background/Objectives: Schizophrenia (SZ) is a complex psychiatric disorder characterized by neurodegenerative processes, but the structural brain alterations associated with its progression remain poorly understood. This study investigated structural brain changes in SZ, particularly in the fronto-temporal and limbic regions, and explored their relationship with symptom severity, with a focus on mood- and emotion-related symptoms. Methods: We analyzed structural MRI data from 74 SZ patients and 91 healthy controls (HCs) using voxel-based morphometry (VBM) to compare whole-brain grey matter volumes (GMVs). The analysis focused on the fronto-temporal and limbic regions, and correlations between GMV and symptom severity were assessed using the Positive and Negative Syndrome Scale (PANSS) and the Generalized Psychopathology (GP) scale. Results: SZ patients exhibited significant reductions in GMV in the fronto-temporal and limbic regions, including the dorsolateral prefrontal cortex (dlPFC) and the temporal pole, compared to HCs. Notably, a significant positive association was found between GMV in the right inferior temporal gyrus (ITG) and the severity of generalized psychopathology, as well as with anxiety, depression, mannerisms, and unusual thought content. Further post hoc analysis identified a specific cluster of mood-related symptoms contributing to the GP scale, which correlated with GMV changes in the right ITG. Conclusions: Our findings provide new evidence of structural brain alterations in SZ, particularly in the fronto-temporal and limbic regions, suggesting a progressive neurodegenerative pattern. The role of the right ITG in mood- and emotion-related symptoms requires further exploration, as it could offer insights into SZ pathophysiology and aid in distinguishing SZ from other mood-related disorders.

Bipolar and schizophrenia risk gene AKAP11 encodes an autophagy receptor coupling the regulation of PKA kinase network homeostasis to synaptic transmission

Human genomic studies have identified protein-truncating variants in AKAP11 associated with both bipolar disorder (BD) and schizophrenia (SCZ), implicating a shared disease mechanism driven by loss-of-function. AKAP11, a protein kinase A (PKA) adaptor, plays a key role in degrading the PKA-RI complex through selective autophagy. However, the neuronal functions of AKAP11 and the impact of its loss-of-function remains largely uncharacterized. Through multi-omics approaches, cell biology, and electrophysiology analysis in mouse models and human induced neurons, we delineated a central role of AKAP11 in coupling PKA kinase network regulation to synaptic transmission. Loss of AKAP11 distorted compartment-specific PKA and GSK3α/β activities and impaired cellular functions that significantly overlap with pathways associated with BD and SCZ. Moreover, we identified interactions between AKAP11, the PKA-RI adaptor SPHKAP, and the ER-resident autophagy-related proteins VAPA/B, which co-adapt and mediate PKA-RI complex degradation in neurons. Notably, AKAP11 deficiency impaired neurotransmission, providing key insights into the mechanism underlying AKAP11-associated psychiatric diseases.

Uncovering synaptic and cellular nanoarchitecture of brain tissue via seamless in situ trimming and milling for cryo-electron tomography

Cell-cell communication underlies all emergent properties of the brain, including cognition, learning and memory. The physical basis for these communications is the synapse, a multi-component structure requiring coordinated interactions between diverse cell types. However, many aspects of three-dimensional (3D) synaptic organization remain poorly understood. Here, we developed an approach, seamless in situ trimming and milling (SISTM), to reliably fabricate sufficiently thin lamellae for mapping of the 3D nanoarchitecture of synapses in mouse, monkey and human brain tissue under near-native conditions via cryo-electron tomography (cryo-ET). We validated SISTM in a mouse model of Huntington's disease, demonstrating distinct 3D alterations to synaptic vesicles and mitochondria. By successfully applying SISTM to macaque brain, we described the 3D architecture of a tripartite synapse within the cortex. Subtomogram averaging (STA) enabled spatial mapping of astrocyte-neuron contacts within the tripartite synapse, revealing neurexin-neuroligin complexes as potential constituents that tether the two cell types. Finally, we showed that the defining features of synaptic nanoarchitecture were conserved across species and evident in human brain tissue obtained postmortem. Combining SISTM with cryo-ET and STA is a starting point for a new understanding of brain organization, disease-induced structural alterations and the development of rational, structure-guided therapeutics.

Androgen effects on mesoprefrontal dopamine systems in the adult male brain

Epidemiological data show that males are more often and/or more severely affected by symptoms of prefrontal cortical dysfunction in schizophrenia, Parkinson's disease and other disorders in which dopamine circuits associated with the prefrontal cortex are dysregulated. This review focuses on research showing that these dopamine circuits are powerfully regulated by androgens. It begins with a brief overview of the sex differences that distinguish prefrontal function in health and prefrontal dysfunction or decline in aging and/or neuropsychiatric disease. This review article then spotlights data from human subjects and animal models that specifically identify androgens as potent modulators of prefrontal cortical operations and of closely related, functionally critical measures of prefrontal dopamine level or tone. Candidate mechanisms by which androgens dynamically control mesoprefrontal dopamine systems and impact prefrontal states of hypo- and hyper-dopaminergia in aging and disease are then considered. This is followed by discussion of a working model that identifies a key locus for androgen modulation of mesoprefrontal dopamine systems as residing within the prefrontal cortex itself. The last sections of this review critically consider the ways in which the organization and regulation of mesoprefrontal dopamine circuits differ in the adult male and female brain, and highlights gaps where more research is needed.

Effects of tDCS with concurrent cognitive performance targeting the dorsolateral prefrontal cortex and the posterior parietal cortex on EEG microstates in schizophrenia

OBJECTIVES

Working memory impairments represent fundamental cognitive deficits in schizophrenia (SZ). Although transcranial direct current stimulation (tDCS) has demonstrated potential in enhancing working memory in SZ, its neural mechanisms and optimized strategies remain to be elucidated. This study explored the effects of tDCS with concurrent cognitive performance targeting the dorsolateral prefrontal cortex (DLPFC) and posterior parietal cortex (PPC) on electroencephalography (EEG) microstates in SZ.

METHODS

This analysis is based on a randomized, double-blind clinical trial of tDCS with concurrent cognitive performance in SZ. Sixty participants were assigned to three groups: active DLPFC, active PPC, and sham stimulation groups. tDCS was administered concurrently with a visual working memory task. The spatial span test was used to assess working memory at baseline, week 1, and week 2, with resting-state EEG data collected at each time point.

RESULTS

No significant differences were detected in the characteristics of the four microstates (A, B, C, and D) at baseline. Compared with the sham stimulation group, the active DLPFC and PPC groups exhibited significant improvements in the duration, occurrence, and coverage of microstate B at week 2. However, the changes in the parameters of microstate B at week 2 were not significantly correlated with working memory improvement.

CONCLUSIONS

This study suggests that neuromodulation targeting different nodes within the task-induced network may influence the same subnetworks in SZ. This work provides new insights into network-based interventions and contributes to the development of multitarget intervention strategies under task conditions.

Clinical application of repetitive transcranial magnetic stimulation in the treatment of chronic pelvic pain syndrome: a scoping review

Introduction

Chronic pelvic pain syndrome is a common condition characterized by persistent symptoms that are difficult to treat. Repetitive transcranial magnetic stimulation (rTMS) is considered a safe treatment option for alleviating chronic pelvic pain, but different stimulation protocols can affect pain relief outcomes. Establishing an optimal stimulation protocol can enhance the uniformity and consistency of rTMS to provide a potentially effective therapeutic intervention. This review sought to systematically review and assess the existing literature on transcranial magnetic stimulation in patients experiencing chronic pelvic pain syndrome, evaluate the therapeutic efficacy, and determine the most effective stimulation protocol.

Methods

A comprehensive search was conducted across three databases, supplemented by manual searches. Two researchers independently reviewed and extracted relevant studies and subsequently performed a thorough analysis of all available clinical data.

Results

A total of eight studies were ultimately incorporated into the analysis. These comprised two randomized controlled trials, one self-controlled trial, two case reports, and three prospective studies. All studies demonstrated a notable reduction in pain scores post-treatment.

Conclusion

rTMS has demonstrated efficacy in alleviating pain in individuals suffering from chronic pelvic pain syndrome. It is regarded as a safe intervention with minimal adverse effects. Nonetheless, the variability observed across studies hindered our ability to conclusively determine the most effective stimulation sites and parameters. Additional research is essential to reduce bias, enhance methodological rigor, and ascertain the optimal conditions and indications for brain stimulation to optimize the therapeutic effectiveness of rTMS.

Systematic Review Registration

https://inplasy.com/projects/, identifier INPLASY2023120112.

Brain-body dysconnectivity: deficient autonomic regulation of cortical function in first-episode schizophrenia

BACKGROUND

An accumulating body of evidence indicates that peripheral physiological rhythms help regulate and organize large-scale brain activity. Given that schizophrenia (SZ) is characterized by marked abnormalities in oscillatory cortical activity as well as changes in autonomic function, the present study aimed to identify mechanisms by which central and autonomic nervous system deficits may be related. We evaluated phase-amplitude coupling (PAC) as a physiological mechanism through which autonomic nervous system (ANS) and central nervous system (CNS) activity are integrated and that may be disrupted in SZ.

METHODS

PAC was measured between high-frequency heart rate variability (HF-HRV) as an index of parasympathetic activity and electroencephalography (EEG) oscillations in 36 individuals with first-episode SZ and 38 healthy comparison participants at rest.

RESULTS

HRV-EEG coupling was lower in SZ in the alpha and theta bands, and HRV-EEG coupling uniquely predicted group membership, whereas HRV and EEG power alone did not. HRV-EEG coupling in the alpha band correlated with measures of sustained attention in SZ. Granger causality analyses indicated a stronger heart-to-brain effect than brain-to-heart effect, consistent across groups.

CONCLUSIONS

Lower HRV-EEG coupling provides evidence of deficient autonomic regulation of cortical activity in SZ, suggesting that patterns of dysconnectivity observed in brain networks extend to brain-body interactions. Deficient ANS-CNS integration in SZ may foster a breakdown in the spatiotemporal organization of cortical activity, which may contribute to core cognitive impairments in SZ such as dysregulated attention. These findings encourage pursuit of therapies targeting autonomic function for the treatment of SZ.

Prefrontal Oscillatory Slowing in Early-Course Schizophrenia Is Associated With Worse Cognitive Performance and Negative Symptoms: A Transcranial Magnetic Stimulation-Electroencephalography Study

BACKGROUND

Abnormalities in dorsolateral prefrontal cortex (DLPFC) oscillations are neurophysiological signatures of schizophrenia thought to underlie its cognitive deficits. Transcranial magnetic stimulation with electroencephalography (TMS-EEG) provides a measure of cortical oscillations unaffected by sensory relay functionality and/or patients' level of engagement, which are important confounding factors in schizophrenia. Previous TMS-EEG work showed reduced fast, gamma-range oscillations and a slowing of the main DLPFC oscillatory frequency, or natural frequency, in chronic schizophrenia. However, it is unclear whether this DLPFC natural frequency slowing is present in early-course schizophrenia (EC-SCZ) and is associated with symptom severity and cognitive dysfunction.

METHODS

We applied TMS-EEG to the left DLPFC in 30 individuals with EC-SCZ and 28 healthy control participants. Goal-directed working memory performance was assessed using the AX-Continuous Performance Task. The EEG frequency with the highest cumulative power at the stimulation site, or natural frequency, was extracted. We also calculated the local relative spectral power as the average power in each frequency band divided by the broadband power.

RESULTS

Compared with the healthy control group, the EC-SCZ group had reduced DLPFC natural frequency (p = .0000002, Cohen's d = -2.32) and higher DLPFC beta-range relative spectral power (p = .0003, Cohen's d = 0.77). In the EC-SCZ group, the DLPFC natural frequency was inversely associated with negative symptoms. Across all participants, the beta band relative spectral power negatively correlated with AX-Continuous Performance Task performance.

CONCLUSIONS

DLPFC oscillatory slowing is an early pathophysiological biomarker of schizophrenia that is associated with its symptom severity and cognitive impairments. Future work should assess whether noninvasive neurostimulation, including repetitive TMS, can ameliorate prefrontal oscillatory deficits and related clinical functions in patients with EC-SCZ.

Bipolar and schizophrenia risk gene AKAP11 encodes an autophagy receptor coupling the regulation of PKA kinase network homeostasis to synaptic transmission

Human genomic studies have identified protein-truncating variants in AKAP11 associated with both bipolar disorder and schizophrenia, implicating a shared disease mechanism driven by loss-of-function. AKAP11, a protein kinase A (PKA) adaptor, plays a key role in degrading the PKA-RI complex through selective autophagy. However, the neuronal functions of AKAP11 and the impact of its loss-of-function remains largely uncharacterized. Through multi-omics approaches, cell biology, and electrophysiology analysis in mouse models and human induced neurons, we delineated a central role of AKAP11 in coupling PKA kinase network regulation to synaptic transmission. Loss of AKAP11 disrupted PKA activity and impaired cellular functions that significantly overlap with pathways associated with the psychiatric disease. Moreover, we identified interactions between AKAP11, the PKA-RI adaptor SPHKAP, and the ER-resident autophagy-related proteins VAPA/B, which co-adapt and mediate PKA-RI degradation. Notably, AKAP11 deficiency impaired neurotransmission and decreased presynaptic protein levels in neurons, providing key insights into the mechanism underlying AKAP11-associated psychiatric diseases.

Subgroups of cognitive impairments in schizophrenia characterized by executive function and their morphological features: a latent profile analysis study

BACKGROUND

The heterogeneity of cognitive impairments in schizophrenia has been widely observed. However, reliable cognitive boundaries to differentiate the subgroups remain elusive. The key challenge for cognitive subtyping is applying an integrated and standardized cognitive assessment and understanding the subgroup-specific neurobiological mechanisms. The present study endeavors to explore cognitive subgroups and identify their morphological features.

METHODS

A total of 920 schizophrenia patients and 169 healthy controls were recruited. MATRICS Consensus Cognitive Battery was applied to assess cognitive performance and recognize cognitive subgroups through latent profile and latent transition analysis. Cortical thickness and gray matter volume were employed for the morphological features across subgroups.

RESULTS

Four reproducible cognitive subgroups were identified, including multidomain-intact, executive-preserved, executive-deteriorated, and multidomain-deteriorated subgroup. After 12 weeks of follow-up, the cognitive characteristics of three out of the four subgroups kept stability, except for multidomain-deteriorated subgroup in which 48.8% of patients with improved cognition transited into the executive-deteriorated subgroup. Across subgroups, significant gradient features of brain structure were exhibited in fronto-temporal regions, hippocampus, and insula. Compared to healthy controls, multidomain-intact subgroup showed the most intact cognition and morphology, and multidomain-deteriorated subgroup with youngest age showed morphological decline in extensive regions. The remaining two subgroups showed intermediate cognitive performance, but could be distinguished by executive function and morphological differences in posterior cingulate cortex.

CONCLUSIONS

Our study provides novel insights into the heterogeneity of cognitive impairments in schizophrenia and the morphological features from cross-sectional and longitudinal levels, which could advance our understanding of complex cognition-morphology relationships and guide personalized interventions.

Connecting genomic results for psychiatric disorders to human brain cell types and regions reveals convergence with functional connectivity

Identifying cell types and brain regions critical for psychiatric disorders and brain traits is essential for targeted neurobiological research. By integrating genomic insights from genome-wide association studies with a comprehensive single-cell transcriptomic atlas of the adult human brain, we prioritized specific neuronal clusters significantly enriched for the SNP-heritabilities for schizophrenia, bipolar disorder, and major depressive disorder along with intelligence, education, and neuroticism. Extrapolation of cell-type results to brain regions reveals the whole-brain impact of schizophrenia genetic risk, with subregions in the hippocampus and amygdala exhibiting the most significant enrichment of SNP-heritability. Using functional MRI connectivity, we further confirmed the significance of the central and lateral amygdala, hippocampal body, and prefrontal cortex in distinguishing schizophrenia cases from controls. Our findings underscore the value of single-cell transcriptomics in understanding the polygenicity of psychiatric disorders and suggest a promising alignment of genomic, transcriptomic, and brain imaging modalities for identifying common biological targets.

Repetitive Transcranial Magnetic Stimulation and Tai Chi Chuan for Older Adults With Sleep Disorders and Mild Cognitive Impairment: A Randomized Clinical Trial

Importance

Sleep disorders and mild cognitive impairment (MCI) commonly coexist in older adults, increasing their risk of developing dementia. Long-term tai chi chuan has been proven to improve sleep quality in older adults. However, their adherence to extended training regimens can be challenging. Repetitive transcranial magnetic stimulation (rTMS) is a neuromodulation technique that may enhance the benefits of exercise.

Objective

To investigate whether 1-Hz rTMS of the right dorsolateral prefrontal cortex could enhance the clinical benefits of tai chi chuan in improving sleep quality and cognitive function among older adults with sleep disorders and MCI.

Design, Setting, and Participants

This 2-arm, sham-controlled, assessor-masked randomized clinical trial was conducted at a university hospital in China between October 2022 and February 2024. Adults aged 60 to 75 years with sleep disorders and MCI were eligible. Data analysis was performed from February to May 2024.

Intervention

Participants were randomized in a 1:1 ratio to an experimental group (tai chi chuan and 1-Hz rTMS) or a sham group (tai chi chuan and sham rTMS). Each participant received 30 sessions of personalized rTMS targeting the right dorsolateral prefrontal cortex, and the sham group underwent the same procedure. The 2 groups received 30 sessions of 60 minutes of the 24-form simplified tai chi chuan, 5 times per week for 6 weeks.

Main Outcomes and Measures

The primary outcomes were subjective sleep quality assessed by the Pittsburgh Sleep Quality Index (PSQI), in which scores range from 0 to 21, with lower scores indicating a healthier sleep quality, and global cognitive function assessed by the Montreal Cognitive Assessment (MoCA), in which scores range from 0 to 30, with higher scores indicating less cognitive impairment. The secondary outcomes included measures of objective sleep actigraphy, anxiety and depression scales, and other cognitive subdomains. Assessments were performed at baseline, 6 weeks after the intervention, and at the 12-week follow-up.

Results

A total of 110 participants (mean [SD] age, 67.9 [4.6] years; 68 female [61.8%]) were randomized to the experimental group (n = 55) and the sham group (n = 55) and included in the intention-to-treat analysis. At 6 weeks after the intervention, compared with the sham group, the experimental group showed a lower PSQI score (between-group mean difference, -3.1 [95% CI, -4.2 to -2.1]; P < .001) and a higher MoCA score (between-group mean difference, 1.4 [95% CI, 0.7-2.1]; P < .001). The per-protocol dataset analyses and 12-week follow-up showed similar results. The generalized estimated equation model revealed an interaction effect between the PSQI score (mean difference, -2.1 [95% CI, -3.1 to -0.1]; P < .001) and the MoCA total score (mean difference, 0.9 [95% CI, 0.1-1.6]; P = .01). There were 7 nonserious, unrelated adverse events (experimental group: 2; sham group: 5) with no significant difference between the 2 groups.

Conclusions and Relevance

In this randomized clinical trial, the findings suggest that 1-Hz rTMS enhanced the clinical benefits of tai chi chuan in improving sleep quality and cognitive function among older adults with sleep disorders and MCI, which may be related to alterations in neural plasticity. These findings provide novel data on nonpharmacologic strategies for the rehabilitation of sleep disorders and may delay or even prevent MCI.

Trial Registration

Chinese Clinical Trial Registry Identifier: ChiCTR2200063274.

White matter lipidome alterations in the schizophrenia brain

Numerous brain imaging studies have reported white matter alterations in schizophrenia, but the lipidome analysis of the corresponding tissue remains incomplete. In this study, we investigated the lipidome composition of six subcortical white matter regions corresponding to major axonal tracks in both control subjects and schizophrenia patients. All six regions exhibited a consistent pattern of quantitative lipidome alterations in schizophrenia, involving myelin-forming and mitochondria associated lipid classes. While alteration levels of myelin-forming lipids, particularly sphingolipids, aligned with the extent of the myelin changes reported in structural brain imaging studies, a significant decrease of mitochondria in the white matter, indicated by the lipidome alterations, was not previously investigated. To verify this effect, we performed lipidome analysis in a larger set of individuals and in the mitochondria-enriched membrane fraction, as well as directly quantified mitochondrial content. Our results suggest a substantial reduction of the mitochondrial quotient accompanied by the imbalance in myelin lipids in schizophrenia white matter.

Exploring Task-Related EEG for Cross-Subject Early Alzheimer's Disease Susceptibility Prediction in Middle-Aged Adults Using Multitaper Spectral Analysis

The early prediction of Alzheimer's disease (AD) risk in healthy individuals remains a significant challenge. This study investigates the feasibility of task-state EEG signals for improving detection accuracy. Electroencephalogram (EEG) data were collected from the Multi-Source Interference Task (MSIT) and Sternberg Memory Task (STMT). Time-frequency features were extracted using the Multitaper method, followed by multidimensional reduction techniques. Subspace features (F24 and F216) were selected via t-tests and False Discovery Rate (FDR) multiple comparisons correction, and subsequently analyzed in the Time-Frequency Area Average Test (TFAAT) and Prefrontal Beta Time Series Test (PBTST). The experimental results reveal that the MSIT task achieves optimal cross-subject classification performance using the Support Vector Machine (SVM) approach with the TFAAT feature set, yielding a Receiver Operating Characteristic Area Under the Curve (ROC AUC) of 58%. Similarly, the Sternberg Memory Task demonstrates classification ability with the logistic regression model applied to the PBTST feature set, emphasizing the beta band power spectrum in the prefrontal cortex as a potential marker of AD risk. These findings confirm that task-state EEG provides stronger classification potential compared to resting-state EEG, offering valuable insights for advancing early AD prediction research.

Functional Connectivity-Based Searchlight Multivariate Pattern Analysis for Discriminating Schizophrenia Patients and Predicting Clinical Variables

BACKGROUND

Schizophrenia, a multifaceted psychiatric disorder characterized by functional dysconnectivity, poses significant challenges in clinical practice. This study explores the potential of functional connectivity (FC)-based searchlight multivariate pattern analysis (CBS-MVPA) to discriminate between schizophrenia patients and healthy controls while also predicting clinical variables.

STUDY DESIGN

We enrolled 112 schizophrenia patients and 119 demographically matched healthy controls. Resting-state functional magnetic resonance imaging data were collected, and whole-brain FC subnetworks were constructed. Additionally, clinical assessments and cognitive evaluations yielded a dataset comprising 36 clinical variables. Finally, CBS-MVPA was utilized to identify subnetworks capable of effectively distinguishing between the patient and control groups and predicting clinical scores.

STUDY RESULTS

The CBS-MVPA approach identified 63 brain subnetworks exhibiting significantly high classification accuracies, ranging from 62.2% to 75.6%, in distinguishing individuals with schizophrenia from healthy controls. Among them, 5 specific subnetworks centered on the dorsolateral superior frontal gyrus, orbital part of inferior frontal gyrus, superior occipital gyrus, hippocampus, and parahippocampal gyrus showed predictive capabilities for clinical variables within the schizophrenia cohort.

CONCLUSION

This study highlights the potential of CBS-MVPA as a valuable tool for localizing the information related to schizophrenia in terms of brain network abnormalities and capturing the relationship between these abnormalities and clinical variables, and thus, deepens our understanding of the neurological mechanisms of schizophrenia.

Molecular Rhythmicity in Glia: Importance for Brain Health and Relevance to Psychiatric Disease

Circadian rhythms are approximate 24-hour rhythms present in nearly all aspects of human physiology, including proper brain function. These rhythms are produced at the cellular level through a transcriptional-translational feedback loop known as the molecular clock. Diurnal variation in gene expression has been demonstrated in brain tissue from multiple species, including humans, in both cortical and subcortical regions. Interestingly, these rhythms in gene expression have been shown to be disrupted across psychiatric disorders and may be implicated in their underlying pathophysiology. However, little is known regarding molecular rhythms in specific cell types in the brain and how they might be involved in psychiatric disease. Although glial cells (e.g., astrocytes, microglia, and oligodendrocytes) have been historically understudied compared to neurons, evidence of the molecular clock is found within each of these cell subtypes. Here, we review the current literature, which suggests that molecular rhythmicity is essential to functional physiologic outputs from each glial subtype. Furthermore, disrupted molecular rhythms within these cells and the resultant functional deficits may be relevant to specific phenotypes across psychiatric illnesses. Given that circadian rhythm disruptions have been so integrally tied to psychiatric disease, the molecular mechanisms governing these associations could represent exciting new avenues for future research and potential novel pharmacologic targets for treatment.

Exploring Cognitive Deficits and Neuromodulation in Schizophrenia: A Narrative Review

Cognitive deficits are emerging as critical targets for managing schizophrenia and enhancing clinical and functional outcomes. These deficits are pervasive among individuals with schizophrenia, affecting various cognitive domains. Traditional pharmacotherapy and cognitive behavioral therapy (CBT) have limitations in effectively addressing cognitive impairments in this population. Neuromodulation techniques show promise in improving certain cognitive domains among patients with schizophrenia spectrum disorders. Understanding the mechanisms of neural circuits that underlie cognitive enhancement is essential for elucidating the pathophysiological processes of the disorder, and these insights could significantly optimize strategies for managing schizophrenia. Meanwhile, although there is an increasing body of evidence demonstrating the therapeutic effects of neuromodulation in this area, further research is still needed, particularly regarding topics such as different treatment protocols and the long-term effects of treatment.

Iowa Gambling Task performance in individuals with schizophrenia: the role of general versus specific cognitive abilities

Objective

We aimed to explore how specific cognitive processes, such as attention and executive functions, account for variance in decision-making measured by Iowa Gambling Task (IGT) performance among individuals with schizophrenia spectrum disorders.

Methods

Adults (N = 65, M age = 25.4) with schizophrenia spectrum disorders participating in a clinical trial (registered at clinicaltrials.gov NCT03048695) completed the IGT, neuropsychological tests of attention, response inhibition, mental flexibility, working memory, and planning, as well as subtests from the Wechsler tests of intelligence to estimate IQ. Associations between performance on specific tasks, a composite score of executive function and attention, and IGT performance measured in two ways, one using the total net score, decks (C+D) - (A+B) and the other as preference for decks with more frequent gains than losses, decks (B+D) - (A+C), were analyzed with correlational and hierarchical regression analysis controlling for estimated IQ and psychotic symptoms, measured by the Positive and Negative Syndrome Scale.

Results

In the regression analyses, the strongest predictor of IGT performance measured as the total net score was estimated IQ (b = 1.43, p <.001). Neither specific cognitive tasks nor the composite score of executive functioning significantly contributed to explaining variance in IGT total net score beyond IQ and symptoms of psychosis. However, IQ and symptoms of psychosis did not predict tendency towards selecting decks with different gain-to-loss frequency, whereas poorer composite executive functioning predicted a pattern of selecting decks A and C with more frequent losses, (b = 8.30, p <.05).

Discussion

The results suggest that both IQ and executive functions contribute to IGT performance, but in distinct ways. Whereas lower IQ may contribute to overall more disadvantageous decision-making, poorer executive functioning may contribute to a more risk-aversive decision-making style. A clinical implication may be that individuals with schizophrenia and lower IQ or poorer executive functioning will have a higher need for support and interventions targeting decision-making.

Unveiling Glutamate Dynamics: Cognitive Demands in Human Short-Term Memory Learning Across Frontal and Parieto-Occipital Cortex: A Functional MRS Study

Background

Acquiring new knowledge necessitates alterations at the synaptic level within the brain. Glutamate, a pivotal neurotransmitter, plays a critical role in these processes, particularly in learning and memory formation. Although previous research has explored glutamate's involvement in cognitive functions, a comprehensive understanding of its real-time dynamics remains elusive during memory tasks.

Objective

This study aimed to investigate glutamate modulation during memory tasks in the right Dorsolateral Prefrontal Cortex (DLPFC) and parieto-occipital regions using functional Magnetic Resonance Spectroscopy (fMRS).

Material and Methods

This experimental research applied fMRS acquisition concurrently with a modified Sternberg's verbal working memory task for fourteen healthy right-handed participants (5 females, mean age=30.64±4.49). The glutamate/total-creatine (Glu/tCr) ratio was quantified by LCModel in the DLPFC and parieto-occipital voxels while applying the tissue corrections.

Results

The significantly higher Glu/tCr modulation was observed during the task with a trend of increased modulation with memory load in both the DLPFC (19.9% higher, P-value=0.018) and parieto-occipital (33% higher, P-value=0.046) regions compared to the rest.

Conclusion

Our pioneering fMRS study has yielded groundbreaking insights into brain functions during S-term Memory (STM) and learning. This research provides valuable methodological advancements for investigating the metabolic functions of both healthy and disordered brains. Based on the findings, cognitive demands directly correlate with glutamate levels, highlighting the neurochemical underpinnings of cognitive processing. Additionally, the obtained results potentially challenge the traditional left-hemisphere-centric model of verbal working memory, leading to the deep vision of hemispheric contributions to cognitive functions.

Case series of patients with early psychosis presenting hypoperfusion in angular gyrus and self-disturbance: Implication for the sense of agency and schizophrenia

BACKGROUND

Self-disturbance has been considered as a core symptomatology of schizophrenia and its emergence from the prodromal phase makes it a crucial target for early detection and intervention in schizophrenia. Currently, the clinical assessment of self-disturbance relies on the self-report of patients, and clinicians have no diagnostic tools in clinical practice. Identifying the neural substrate of self-disturbance would be of great clinical value by shedding light on the core dimension of schizophrenia.

CASE PRESENTATION

We first introduce an adolescent patient who initially presented self-disturbance, and clinically detectable hypoperfusion in angular gyrus (AG) was observed when early psychosis was suspected. Interestingly, the hypoperfusion in AG may correspond to improvement and exacerbation of self-disturbance. This clinical observation led us to pursue the relationship between the decreased blood flow in the AG and self-disturbance. Among 15 cases with suspected early psychosis in which single photon emission computed tomography was performed to exclude organic factors, we found additional 5 cases, including one prodromal patient, showing hypoperfusion in the AG and self-disturbance with significant correlation (r = 0.79, p = 0.00025).

DISCUSSION

The self-disturbance has been interpreted as a reflection of disturbance of the "Sense of Agency", the ability to attribute their action and/or thoughts to themselves. AG has been shown to play a pivotal role in the sense of agency. These cases suggest that the hypoperfusion in AG associated with the disruption in the sense of agency would be an early clinical sign of schizophrenia. Further longitudinal studies are needed to test this hypothesis.

A prefrontal thalamocortical readout for conflict-related executive dysfunction in schizophrenia

Executive dysfunction is a prominent feature of schizophrenia and may drive core symptoms. Dorsolateral prefrontal cortex (dlPFC) deficits have been linked to schizophrenia executive dysfunction, but mechanistic details critical for treatment development remain unclear. Here, capitalizing on recent animal circuit studies, we develop a task predicted to engage human dlPFC and its interactions with the mediodorsal thalamus (MD). We find that individuals with schizophrenia exhibit selective performance deficits when attention is guided by conflicting cues. Task performance correlates with lateralized MD-dlPFC functional connectivity, identifying a neural readout that predicts susceptibility to conflict during working memory in a larger independent schizophrenia cohort. In healthy subjects performing a probabilistic reversal task, this MD-dlPFC network predicts switching behavior. Overall, our three independent experiments introduce putative biomarkers for executive function in schizophrenia and highlight animal circuit studies as inspiration for the development of clinically relevant readouts.

Gene expression analysis of Schizophrenia

Schizophrenia is a chronic psychiatric disorder marked by cognitive deficits associated with prefrontal cortical dysfunction, particularly in Broadmann Area 10 (BA 10), where gray matter reduction is observed. The genetic mechanisms behind these abnormalities remain unclear. Therefore, it is of interest to analyze altered gene expression and pathways in the prefrontal cortex of schizophrenia patients. We used two GEO datasets - GSE12654 (discovery) and GSE17612 (validation) and differential gene expression was assessed between schizophrenia patients and healthy controls. Validation confirmed three upregulated genes (S100A9, S100A8, BCL2A1) and one downregulated gene (CBLB), with protein interaction analysis revealing that upregulated genes were linked to immune and apoptotic processes, while downregulated genes suppressed EGF pathways. These findings suggest immune dysfunction and gray matter loss in schizophrenia, highlighting potential biomarkers and therapeutic targets.

Alterations in inhibitory neuron subtype-selective transcripts in the prefrontal cortex: comparisons across schizophrenia and mood disorders

BACKGROUND

In schizophrenia (SZ), impairments in cognitive functions, such as working memory, have been associated with alterations in certain types of inhibitory neurons that utilize the neurotransmitter γ-aminobutyric acid (GABA) in the dorsolateral prefrontal cortex (DLPFC). For example, GABA neurons that express parvalbumin (PV) or somatostatin (SST) have more prominent gene expression alterations than those that express vasoactive intestinal peptide (VIP). In bipolar disorder (BD) and major depression (MD), which exhibit similar, but less severe, cognitive impairments than SZ, alterations of transcript levels in GABA neurons have also been reported. However, the extent to which GABA neuron subtype-selective transcripts in the DLPFC are affected, and the relative magnitudes of the diagnosis-associated effects, have not been directly compared across SZ, BD, and MD in the same study.

METHODS

We used quantitative polymerase chain reaction to examine levels of GABA neuron subtype-selective transcripts (PV, potassium voltage-gated channel modifier subfamily-S member-3, SST, VIP, and calretinin mRNAs), as well as the pan-GABA neuron marker 67 kDa glutamate decarboxylase mRNA, in DLPFC total gray matter of 160 individuals, including those with SZ, BD, or MD and unaffected comparison (UC) individuals.

RESULTS

Relative to UC individuals, individuals with SZ exhibited large deficits in levels of all transcripts except for calretinin mRNA, whereas individuals with BD or MD showed a marked deficit only for PV or SST mRNAs, respectively.

CONCLUSIONS

These findings suggest that broader and more severe alterations in DLPFC GABA neurons might contribute to the greater cognitive impairments in SZ relative to BD and MD.

Diagnosis of schizophrenia by integrated saccade scores and associations with psychiatric symptoms, and functioning

Eye movement as a neurobiological biomarker of schizophrenia. We aim to estimate diagnostic accuracy of integrated pro/antisaccade eye movement measurements to discriminate between healthy individuals and schizophrenic patients. We compared the eye movement performance of 85 healthy individuals and 116 schizophrenia-stable patients during prosaccade and antisaccade tasks. The difference eye movement measurements were accumulated by stepwise discriminant analysis to produce an integrated score. Finally, the diagnostic value of the integrated score was calculated by the receiver operating characteristic (ROC) area under the curve (AUC), and the best sensitivity and specificity were calculated based on the given cutoff values. Using discriminant analysis, an integrated score included the residual gain and latency (step) during the prosaccade test, the error rate, and the corrected error rate during the antisaccade test. We found that the integrated score could well classify schizophrenia patients and healthy individuals with an accuracy of 80.6%. In the ROC, Youden's index was 0.634 (sensitivity = 81.0%, specificity = 82.4%) and AUC was 0.871. There were significant difference patterns of correlation between the severity of psychiatric symptoms and daily functioning and diagnostic eye movement measurements. Using only 2 saccade tasks to discriminate well between schizophrenia patients and healthy controls, suggesting that abnormalities in saccade behavior is a potential biomarker and efficient diagnostic tool for identifying schizophrenia. The underlying neuropathologic mechanisms associated with abnormal saccades may provide insights into the intervention and diagnosis of schizophrenia.

A Comparative Study of Frontal and Cerebellar Lobe Volumes Between Patients With First-Episode Schizophrenia and Healthy Controls and Its Association With Psychopathology and Neurological Soft Signs in Patients

Objectives Our study aimed to investigate the fronto-cerebellar volumes in both patients and controls, as well as explore their relationship with symptomatology. Our primary objectives were to compare the frontal and cerebellar lobe volumetric measurements between patients with first-episode schizophrenia (FES) and healthy controls and to assess the relationship of these volumes with psychopathology, cognition, and neurological soft signs in FES patients. The secondary objective was to explore the association of fronto-cerebellar lobe volumes with socio-demographic factors among patients and controls, as well as the duration of untreated illness (DUI) among patients. Materials and methods This was a cross-sectional, case-control study involving 60 participants, including 30 antipsychotic-naïve FES patients and 30 healthy controls. Participants underwent MRI scanning to measure frontal and cerebellar lobe volumes using the volBrain platform. Additionally, FES patients were assessed using the Positive and Negative Syndrome Scale (PANSS), Montreal Cognitive Assessment-Basic (MoCA-B), and Brief Motor Scale (BMS). Pearson's correlation, independent sample t-tests, multivariate linear regression, and binomial logistic regression were used to analyze the relationships between brain volumes, clinical assessments, and socio-demographic factors. Results No significant differences in frontal volumes were found between the two groups, while cerebellar volumes were significantly smaller in FES patients (p=0.004), particularly in younger males (p=0.026). Frontal volumes were negatively correlated with age in both groups (p=0.012), which remained robust in patients even after controlling for their gender, education, and DUI (p=0.012, aR2=0.221). Cerebellar volume reduction was associated with a higher likelihood of being classified as a patient (p=0.029). BMS was significantly correlated with frontal lobe volumes, especially in motor sequencing (MoSe), after adjusting for age, gender, and education (p=0.009). BMS MoSe scores were also significantly positively correlated with the DUI (r=0.415, p=0.023) and PANSS-General Psychopathology (GP) (r=0.494, p=0.005). MoCA-B scores were significantly lower in females than males (p=0.016), while PANSS-GP was significantly negatively correlated with age (r=-0.432, p=0.017). Conclusion Frontal and cerebellar volumes were differentially impacted in FES, with cerebellar atrophy being a significant distinguishing feature of the disorder. Frontal atrophy was associated with motor dysfunction but did not appear to influence psychopathology or cognition significantly in the early stages. The independent effects of frontal and cerebellar volumes, as shown by the lack of correlation between them, may suggest that these brain regions undergo separate pathological processes in schizophrenia, with frontal functional changes impacting motor function and cerebellar structural changes contributing to broader psychiatric symptoms, thereby warranting further exploration involving larger sample size.

The excitatory-inhibitory balance as a target for the development of novel drugs to treat schizophrenia

The intricate balance between excitation and inhibition (E/I) in the brain plays a crucial role in normative information processing. Dysfunctions in the E/I balance have been implicated in various psychiatric disorders, including schizophrenia (SCZ). In particular, abnormalities in GABAergic signaling, specifically in parvalbumin (PV)-containing interneurons, have been consistently observed in SCZ pathophysiology. PV interneuron function is vital for maintaining an ideal E/I balance, and alterations in PV interneuron-mediated inhibition contribute to circuit deficits observed in SCZ, including hippocampus hyperactivity and midbrain dopamine system overdrive. While current antipsychotic medications primarily target D2 dopamine receptors and are effective primarily in treating positive symptoms, novel therapeutic strategies aiming to restore the E/I balance could potentially mitigate not only positive symptoms but also negative symptoms and cognitive deficits. This could involve, for instance, increasing the inhibitory drive onto excitatory neurons or decreasing the putative enhanced pyramidal neuron activity due to functional loss of PV interneurons. Compounds targeting the glycine site at glutamate NMDA receptors and muscarinic acetylcholine receptors on PV interneurons that can increase PV interneuron drive, as well as drugs that increase the postsynaptic action of GABA, such as positive allosteric modulators of α5-GABA-A receptors, and decrease glutamatergic output, such as mGluR2/3 agonists, represent promising approaches. Preventive strategies aiming at E/I balance also represent a path to reduce the risk of transitioning to SCZ in high-risk individuals. Therefore, compounds with novel mechanisms targeting E/I balance provide optimism for more effective and tailored interventions in the management of SCZ.

Personalised transcranial magnetic stimulation for treatment-resistant depression, depression with comorbid anxiety and negative symptoms of schizophrenia: a narrative review

ABSTRACT

Transcranial magnetic stimulation (TMS) is a promising intervention for treatment-resistant psychiatric disorders. However, conventional TMS typically utilises a one-size-fits-all approach when determining stimulation targets. Recent retrospective brain circuit-based analyses using lesion network mapping have suggested that a left dorsal lateral prefrontal cortex target has a higher efficacy for alleviating depression symptoms, a dorsomedial prefrontal cortex target is more effective for anxiety symptoms, and a rostromedial prefrontal cortex target is effective for schizophrenia-associated psychiatric symptoms. Nonetheless, symptom-specific brain circuit targeting has not been tested prospectively. We conducted a narrative review of selected literature to investigate individualised targeting for TMS and discuss potential future directions to elucidate the efficacy of this approach.

Rapid context inference in a thalamocortical model using recurrent neural networks

Cognitive flexibility is a fundamental ability that enables humans and animals to exhibit appropriate behaviors in various contexts. The thalamocortical interactions between the prefrontal cortex (PFC) and the mediodorsal thalamus (MD) have been identified as crucial for inferring temporal context, a critical component of cognitive flexibility. However, the neural mechanism responsible for context inference remains unknown. To address this issue, we propose a PFC-MD neural circuit model that utilizes a Hebbian plasticity rule to support rapid, online context inference. Specifically, the model MD thalamus can infer temporal contexts from prefrontal inputs within a few trials. This is achieved through the use of PFC-to-MD synaptic plasticity with pre-synaptic traces and adaptive thresholding, along with winner-take-all normalization in the MD. Furthermore, our model thalamus gates context-irrelevant neurons in the PFC, thus facilitating continual learning. We evaluate our model performance by having it sequentially learn various cognitive tasks. Incorporating an MD-like component alleviates catastrophic forgetting of previously learned contexts and demonstrates the transfer of knowledge to future contexts. Our work provides insight into how biological properties of thalamocortical circuits can be leveraged to achieve rapid context inference and continual learning.

Unveiling Promising Neuroimaging Biomarkers for Schizophrenia Through Clinical and Genetic Perspectives

Schizophrenia is a complex and serious brain disorder. Neuroscientists have become increasingly interested in using magnetic resonance-based brain imaging-derived phenotypes (IDPs) to investigate the etiology of psychiatric disorders. IDPs capture valuable clinical advantages and hold biological significance in identifying brain abnormalities. In this review, we aim to discuss current and prospective approaches to identify potential biomarkers for schizophrenia using clinical multimodal neuroimaging and imaging genetics. We first described IDPs through their phenotypic classification and neuroimaging genomics. Secondly, we discussed the applications of multimodal neuroimaging by clinical evidence in observational studies and randomized controlled trials. Thirdly, considering the genetic evidence of IDPs, we discussed how can utilize neuroimaging data as an intermediate phenotype to make association inferences by polygenic risk scores and Mendelian randomization. Finally, we discussed machine learning as an optimum approach for validating biomarkers. Together, future research efforts focused on neuroimaging biomarkers aim to enhance our understanding of schizophrenia.

Elevations in the Mitochondrial Matrix Protein Cyclophilin D Correlate With Reduced Parvalbumin Expression in the Prefrontal Cortex of Patients With Schizophrenia

BACKGROUND AND HYPOTHESIS

Cognitive deficits in schizophrenia are linked to dysfunctions of the dorsolateral prefrontal cortex (DLPFC), including alterations in parvalbumin (PV)-expressing interneurons (PVIs). Redox dysregulation and oxidative stress may represent convergence points in the pathology of schizophrenia, causing dysfunction of GABAergic interneurons and loss of PV. Here, we show that the mitochondrial matrix protein cyclophilin D (CypD), a critical initiator of the mitochondrial permeability transition pore (mPTP) and modulator of the intracellular redox state, is altered in PVIs in schizophrenia.

STUDY DESIGN

Western blotting was used to measure CypD protein levels in postmortem DLPFC specimens of schizophrenic patients (n = 27) and matched comparison subjects with no known history of psychiatric or neurological disorders (n = 26). In a subset of this cohort, multilabel immunofluorescent confocal microscopy with unbiased stereological sampling methods were used to quantify (1) numbers of PVI across the cortical mantle (20 unaffected comparison, 14 schizophrenia) and (2) PV and CypD protein levels from PVIs in the cortical layers 2-4 (23 unaffected comparison, 18 schizophrenia).

STUDY RESULTS

In schizophrenic patients, the overall number of PVIs in the DLPFC was not significantly altered, but in individual PVIs of layers 2-4 PV protein levels decreased along a superficial-to-deep gradient when compared to unaffected comparison subjects. These laminar-specific PVI alterations were reciprocally linked to significant CypD elevations both in PVIs and total DLPFC gray matter.

CONCLUSIONS

Our findings support previously reported PVI anomalies in schizophrenia and suggest that CypD-mediated mPTP formation could be a potential contributor to PVI dysfunction in schizophrenia.

Molecular and cellular rhythms in excitatory and inhibitory neurons in the mouse prefrontal cortex

Previous studies have shown that there are rhythms in gene expression in the mouse prefrontal cortex (PFC); however, the contribution of different cell types and potential variation by sex has not yet been determined. Of particular interest are excitatory pyramidal cells and inhibitory parvalbumin (PV) interneurons, as interactions between these cell types are essential for regulating the excitation/inhibition balance and controlling many of the cognitive functions regulated by the PFC. In this study, we identify cell-type specific rhythms in the translatome of PV and pyramidal cells in the mouse PFC and assess diurnal rhythms in PV cell electrophysiological properties. We find that while core molecular clock genes are conserved and synchronized between cell types, pyramidal cells have nearly twice as many rhythmic transcripts as PV cells (35% vs. 18%). Rhythmic transcripts in pyramidal cells also show a high degree of overlap between sexes, both in terms of which transcripts are rhythmic and in the biological processes associated with them. Conversely, in PV cells, rhythmic transcripts from males and females are largely distinct. Moreover, we find sex-specific effects of phase on action potential properties in PV cells that are eliminated by environmental circadian disruption. Together, this study demonstrates that rhythms in gene expression and electrophysiological properties in the mouse PFC vary by both cell type and sex. Moreover, the biological processes associated with these rhythmic transcripts may provide insight into the unique functions of rhythms in these cells, as well as their selective vulnerabilities to circadian disruption.

Overlap between individual differences in cognition and symptoms of schizophrenia

BACKGROUND

Neurocognitive impairment is a core feature of schizophrenia spectrum disorders (SSDs), and the relationship between cognition and symptoms in SSDs has been widely researched. Negative symptoms are related to a wide range of cognitive impairments; however, the aspects of negative symptoms that underpin this relationship have yet to be specified.

STUDY DESIGN

We used iterative Constrained Principal Component Analysis (iCPCA) to explore the relationship between 18 cognitive measures (including processing speed, attention, working, spatial and verbal memory and executive functions) and 46 symptoms in schizophrenia at the individual item level while minimizing the risk of Type I errors. ICPCA was conducted on a sample of SSD patients in the early stages of psychiatric treatment (n = 121) to determine the components of cognition overlapping with symptoms measured by the Scale for the Assessment of Negative Symptoms (SANS) and the Scale for the Assessment of Positive Symptoms (SAPS).

RESULTS

We found that a verbal memory component was associated with items from SANS and SAPS related to impoverished and disorganized emotional communication, language, and thought. In contrast, a working memory component was associated with SANS items related to motor system impoverishment.

CONCLUSIONS

The iCPCA allowed us to explore the associations between individual items, optimized to understand the overlap between symptoms and cognition. The specific symptoms linked to verbal and working memory impairments imply distinct brain networks, which further investigation may lead to our deeper understanding of the illness and the development of treatment methods.

The Effect of Maternal High-Fat or High-Carbohydrate Diet during Pregnancy and Lactation on Cytochrome P450 2D (CYP2D) in the Liver and Brain of Rat Offspring

Cytochrome P450 2D (CYP2D) is important in psychopharmacology as it is engaged in the metabolism of drugs, neurosteroids and neurotransmitters. An unbalanced maternal diet during pregnancy and lactation can cause neurodevelopmental abnormalities and increases the offspring's predisposition to neuropsychiatric diseases. The aim of the present study was to evaluate the effect of maternal modified types of diet: a high-fat diet (HFD) and high-carbohydrate diet (HCD) during pregnancy and lactation on CYP2D in the liver and brain of male offspring at 28 (adolescent) or 63 postnatal days (young adult). The CYP2D activity and protein level were measured in the liver microsomes and the levels of mRNAs of CYP2D1, 2D2 and 2D4 were investigated both in the liver and brain. In the liver, both HFD and HCD increased the mRNA levels of all the three investigated CYP2D genes in adolescents, but an opposite effect was observed in young adults. The CYP2D protein level increased in adolescents but not in young adults. In contrast, young adults showed significantly decreased CYP2D activity. Similar effect of HFD on the CYP2D mRNAs was observed in the prefrontal cortex, while the effect of HCD was largely different than in the liver (the CYP2D2 expression was not affected, the CYP2D4 expression was decreased in young adults). In conclusion, modified maternal diets influence the expression of individual CYP2D1, CYP2D2 and CYP2D4 genes in the liver and brain of male offspring, which may affect the metabolism of CYP2D endogenous substrates and drugs and alter susceptibility to brain diseases and pharmacotherapy outcome.

Increased regional activity of a pro-autophagy pathway in schizophrenia as a contributor to sex differences in the disease pathology

Based on recent genome-wide association studies, it is theorized that altered regulation of autophagy contributes to the pathophysiology of schizophrenia and bipolar disorder. As activity of autophagy-regulatory pathways is controlled by discrete phosphorylation sites on the relevant proteins, phospho-protein profiling is one of the few approaches available for enabling a quantitative assessment of autophagic activity in the brain. Despite this, a comprehensive phospho-protein assessment in the brains of schizophrenia and bipolar disorder subjects is currently lacking. Using this direction, our broad screening identifies an increase in AMP-activated protein kinase (AMPK)-mediated phospho-activation of the pro-autophagy protein beclin-1 solely in the prefrontal cortex of female, but not male, schizophrenia subjects. Using a reverse translational approach, we surprisingly find that this increase in beclin-1 activity facilitates synapse formation and enhances cognition. These findings are interpreted in the context of human studies demonstrating that female schizophrenia subjects have a lower susceptibility to cognitive dysfunction than males.

Effect of transcranial direct current stimulation with concurrent cognitive performance targeting posterior parietal cortex vs prefrontal cortex on working memory in schizophrenia: a randomized clinical trial

Working memory deficits are linked to irregularities in the dorsolateral prefrontal cortex (DLPFC) and the posterior parietal cortex (PPC) in schizophrenia, effective intervention strategies are lacking. We evaluated the differential efficacy and underlying neuromechanisms of targeting transcranial direct current stimulation (tDCS) at the DLPFC and the PPC with concurrent cognitive performance for working memory in schizophrenia. In a randomized and double-blind clinical trial, sixty clinically stable schizophrenic patients with below-average working memory were randomly assigned to active DLPFC, active PPC, and sham tDCS groups. Two sessions of tDCS during N-back task were delivered daily for five days. The primary outcome was changes in spatial span test scores from baseline to week 1. The secondary outcomes included changes in scores of color delay-estimation task, other cognitive tasks, and mismatch negativity (biomarker of N-methyl-d-aspartate receptor functioning). Compared with the active DLPFC group, the active PPC group demonstrated significantly greater improvement in spatial span test scores (p = 0.008, d = 0.94) and an augmentation in color delay-estimation task capacity at week 1; the latter sustained to week 2. Compared with the sham tDCS group, the active PPC group did not show a significant improvement in spatial span test scores at week 1 and 2; however, significant enhancement was observed in their color delay-estimation task capacity at week 2. Additionally, mismatch negativity amplitude was enhanced, and changes in theta band measures were positively correlated with working memory improvement in the active PPC group, while no such correlations were observed in the active DLPFC group or the sham tDCS group. Our results suggest that tDCS targeting the PPC relative to the DLPFC during concurrent cognitive performance may improve working memory in schizophrenia, meriting further investigation. The improvement in working memory appears to be linked to enhanced N-methyl-d-aspartate receptor functioning.

Intermittent Theta Burst Stimulation Combined with Cognitive Training to Improve Negative Symptoms and Cognitive Impairment in Schizophrenia: A Pilot Study

Schizophrenia is a chronic psychiatric disorder severely affecting patients' functioning and quality of life. Unlike positive symptoms, cognitive impairment and negative symptoms cannot be treated pharmacologically and represent consistent predictors of the illness's prognosis. Cognitive remediation (CR) interventions have been applied to target these symptoms. Brain stimulation also provides promising yet preliminary results in reducing negative symptoms, whereas its effect on cognitive impairment remains heterogeneous. Here, we combined intermittent theta burst stimulation (iTBS) with CR to improve negative symptoms and cognitive impairment in schizophrenia spectrum patients. One hundred eligible patients were invited, and twenty-one participated. We randomized them into four groups, manipulating the stimulation condition (real vs. sham) and CR (no training vs. training). We delivered fifteen iTBS sessions over the left dorsolateral prefrontal cortex for three weeks, followed (or not) by 50 min of training. Consensus-based clinical and cognitive assessment was administered at baseline and after the treatment, plus at three follow-ups occurring one, three, and six months after the intervention. Mixed-model analyses were run on cognitive and negative symptom scores. The preliminary findings highlighted a marginal modulation of iTBS on negative symptoms, whereas CR improved isolated cognitive functions. We herein discuss the limitations and strengths of the methodological approach.

Overview on cognitive impairment in psychotic disorders: From impaired microcircuits to dysconnectivity

Schizophrenia's cognitive deficits, often overshadowed by positive symptoms, significantly contribute to the disorder's morbidity. Increasing attention highlights these deficits as reflections of neural circuit dysfunction across various cortical regions. Numerous connectivity alterations linked to cognitive symptoms in psychotic disorders have been reported, both at the macroscopic and microscopic level, emphasizing the potential role of plasticity and microcircuits impairment during development and later stages. However, the heterogeneous clinical presentation of cognitive impairment and diverse connectivity findings pose challenges in summarizing them into a cohesive picture. This review aims to synthesize major cognitive alterations, recent insights into network structural and functional connectivity changes and proposed mechanisms and microcircuit alterations underpinning these symptoms, particularly focusing on neurodevelopmental impairment, E/I balance, and sleep disturbances. Finally, we will also comment on some of the most recent and promising therapeutic approaches that aim to target these mechanisms to address cognitive symptoms. Through this comprehensive exploration, we strive to provide an updated and nuanced overview of the multiscale connectivity impairment underlying cognitive impairment in psychotic disorders.

Synaptic alterations in pyramidal cells following genetic manipulation of neuronal excitability in monkey prefrontal cortex

In schizophrenia, layer 3 pyramidal neurons (L3PNs) in the dorsolateral prefrontal cortex (DLPFC) are thought to receive fewer excitatory synaptic inputs and to have lower expression levels of activity-dependent genes and of genes involved in mitochondrial energy production. In concert, these findings from previous studies suggest that DLPFC L3PNs are hypoactive in schizophrenia, disrupting the patterns of activity that are crucial for working memory, which is impaired in the illness. However, whether lower PN activity produces alterations in inhibitory and/or excitatory synaptic strength has not been tested in the primate DLPFC. Here, we decreased PN excitability in rhesus monkey DLPFC in vivo using adeno-associated viral vectors (AAVs) to produce Cre recombinase-mediated overexpression of Kir2.1 channels, a genetic silencing tool that efficiently decreases neuronal excitability. In acute slices prepared from DLPFC 7-12 weeks post-AAV microinjections, Kir2.1-overexpressing PNs had a significantly reduced excitability largely attributable to highly specific effects of the AAV-encoded Kir2.1 channels. Moreover, recordings of synaptic currents showed that Kir2.1-overexpressing DLPFC PNs had reduced strength of excitatory synapses whereas inhibitory synaptic inputs were not affected. The decrease in excitatory synaptic strength was not associated with changes in dendritic spine number, suggesting that excitatory synapse quantity was unaltered in Kir2.1-overexpressing DLPFC PNs. These findings suggest that, in schizophrenia, the excitatory synapses on hypoactive L3PNs are weaker and thus might represent a substrate for novel therapeutic interventions.

Significance Statement

In schizophrenia, dorsolateral prefrontal cortex (DLPFC) pyramidal neurons (PNs) have both transcriptional and structural alterations that suggest they are hypoactive. PN hypoactivity is thought to produce synaptic alterations in schizophrenia, however the effects of lower neuronal activity on synaptic function in primate DLPFC have not been examined. Here, we used, for the first time in primate neocortex, adeno-associated viral vectors (AAVs) to reduce PN excitability with Kir2.1 channel overexpression and tested if this manipulation altered the strength of synaptic inputs onto the Kir2.1-overexpressing PNs. Recordings in DLPFC slices showed that Kir2.1 overexpression depressed excitatory (but not inhibitory), synaptic currents, suggesting that, in schizophrenia, the hypoactivity of PNs might be exacerbated by reduced strength of the excitatory synapses they receive.

Cognitive impairment in schizophrenia is associated with prefrontal-striatal functional hypoconnectivity and striatal dopaminergic abnormalities

BACKGROUND

A better understanding of the mechanisms underlying cognitive impairment in schizophrenia is imperative, as it causes poor functional outcomes and a lack of effective treatments.

AIMS

This study aimed to investigate the relationships of two proposed main pathophysiology of schizophrenia, altered prefrontal-striatal connectivity and the dopamine system, with cognitive impairment and their interactions.

METHODS

Thirty-three patients with schizophrenia and 27 healthy controls (HCs) who are right-handed and matched for age and sex were recruited. We evaluated their cognition, functional connectivity (FC) between the dorsolateral prefrontal cortex (DLPFC)/middle frontal gyrus (MiFG) and striatum, and the availability of striatal dopamine transporter (DAT) using a cognitive battery investigating attention, memory, and executive function, resting-state functional magnetic resonance imaging with group independent component analysis and single-photon emission computed tomography with 99mTc-TRODAT.

RESULTS

Patients with schizophrenia exhibited poorer cognitive performance, reduced FC between DLPFC/MiFG and the caudate nucleus (CN) or putamen, decreased DAT availability in the left CN, and decreased right-left DAT asymmetry in the CN compared to HCs. In patients with schizophrenia, altered imaging markers are associated with cognitive impairments, especially the relationship between DLPFC/MiFG-putamen FC and attention and between DAT asymmetry in the CN and executive function.

CONCLUSIONS

This study is the first to demonstrate how prefrontal-striatal hypoconnectivity and altered striatal DAT markers are associated with different domains of cognitive impairment in schizophrenia. More research is needed to evaluate their complex relationships and potential therapeutic implications.

Transcranial alternating current stimulation in affecting cognitive impairment in psychiatric disorders: a review

Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation method that, through its manipulation of endogenous oscillations, can affect cognition in healthy adults. Given the fact that both endogenous oscillations and cognition are impaired in various psychiatric diagnoses, tACS might represent a suitable intervention. We conducted a search of Pubmed and Web of Science databases and reviewed 27 studies where tACS is used in psychiatric diagnoses and cognition change is evaluated. TACS is a safe and well-tolerated intervention method, suitable for multiple-sessions protocols. It can be administered at home, individualized according to the patient''s anatomical and functional characteristics, or used as a marker of disease progression. The results are varying across diagnoses and applied protocols, with some protocols showing a long-term effect. However, the overall number of studies is small with a great variety of diagnoses and tACS parameters, such as electrode montage or used frequency. Precise mechanisms of tACS interaction with pathophysiological processes are only partially described and need further research. Currently, tACS seems to be a feasible method to alleviate cognitive impairment in psychiatric patients; however, a more robust confirmation of efficacy of potential protocols is needed to introduce it into clinical practise.

A data-driven single-cell and spatial transcriptomic map of the human prefrontal cortex

The molecular organization of the human neocortex historically has been studied in the context of its histological layers. However, emerging spatial transcriptomic technologies have enabled unbiased identification of transcriptionally defined spatial domains that move beyond classic cytoarchitecture. We used the Visium spatial gene expression platform to generate a data-driven molecular neuroanatomical atlas across the anterior-posterior axis of the human dorsolateral prefrontal cortex. Integration with paired single-nucleus RNA-sequencing data revealed distinct cell type compositions and cell-cell interactions across spatial domains. Using PsychENCODE and publicly available data, we mapped the enrichment of cell types and genes associated with neuropsychiatric disorders to discrete spatial domains.

High-Frequency Repetitive Transcranial Magnetic Stimulation on Overall Cognition in Patients With Poststroke Cognitive Impairment: A Systematic Review and Meta-analysis

OBJECTIVE

The aim of the study is to comprehensively assess the recovery effects of high-frequency repetitive transcranial magnetic stimulation in patients with poststroke cognitive impairment.

METHODS

Six English and four Chinese databases were searched for relevant studies published up to January 2022. Randomized controlled trials of patients with poststroke cognitive impairment treated with high-frequency repetitive transcranial magnetic stimulation were included. Included studies were assessed for the risk of bias through the Cochrane Intervention Systematic Review Manual 5.1.0. The meta-analysis was performed using RevMan 5.4 software. The PRISMA 2020 guidelines were followed.

RESULTS

Sixty-one randomized controlled trials (4012 patients) were included. Montreal Cognitive Assessment Score, Mini-Mental State Examination score, event-related potential P300 (P300) amplitude, Loewenstein Occupational Therapy Cognitive Assessment score, and total effective rate of cognitive function were higher in the high-frequency repetitive transcranial magnetic stimulation group than in the control group at the end of the treatment period, and scores of Alzheimer Disease Assessment Scale-Cognitive Subscale and P300 latency were lower in the high-frequency repetitive transcranial magnetic stimulation group than in the control group. Fifty studies had selected the dorsolateral prefrontal cortex as the stimulation site for high-frequency repetitive transcranial magnetic stimulation.

CONCLUSIONS

Compared with nonrepetitive transcranial magnetic stimulation or sham repetitive transcranial magnetic stimulation, high-frequency repetitive transcranial magnetic stimulation not only improves the overall cognitive function of poststroke cognitive impairment patients but also has better rehabilitation results.

Eye movements as predictor of cognitive improvement after cognitive remediation therapy in patients with schizophrenia

AIM

Baseline cognitive functions of patients predicted the efficacy of cognitive remediation therapy (CRT), but results are mixed. Eye movement is a more objective and advanced assessment of cognitive functions than neuropsychological testing. We aimed to investigate the applicability of eye movements in predicting cognitive improvement after patients with schizophrenia were treated with CRT.

METHODS

We recruited 79 patients with schizophrenia to complete 8 weeks of CRT and assessed their cognitive improvement outcomes. Eye movements were assessed by prosaccades, antisaccades, and free-viewing tasks at baseline, and neuropsychological tests in four cognitive domains were assessed before and after treatment to calculate treatment outcomes. Predictors of demographic information, clinical characteristics, and eye movement measures at baseline on cognitive improvement outcomes were analyzed using logistic regression analysis. We further compared the predictive performance between eye movement measurements and neuropsychological test regarding the effect of CRT on cognitive improvement, and explored factors that could be affect the treatment outcomes in different cognitive domains.

RESULTS

As operationally defined, 33 patients showed improved in cognition (improved group) and 46 patients did not (non-improved group) after CRT. Patients with schizophrenia being employed, lower directional error rate in antisaccade task, and lower the gap effect (i.e., the difference in saccadic latency between the gap condition and overlap condition) in prosaccade task at baseline predicted cognitive improvement in CRT. However, performance in the free-viewing task not associated with cognitive improvement in patients in CRT. Our results show that eye-movement prediction model predicted the effect of CRT on cognitive improvement in patients with schizophrenia better than neuropsychological prediction model in CRT. In addition, baseline eye-movements, cognitive reserve, antipsychotic medication dose, anticholinergic cognitive burden change, and number of training sessions were associated with improvements in four cognitive domains.

CONCLUSION

Eye movements as a non-invasiveness, objective, and sensitive method of evaluating cognitive function, and combined saccadic measurements in pro- and anti-saccades tasks could be more beneficial than free-viewing task in predicting the effect of CRT on cognitive improvement in patients with schizophrenia.