Toward recovery in schizophrenia: Current concepts, findings, and future research directions

Brain metabolic profiling of schizophrenia: a path towards a better understanding of the neuropathogenesis of psychosis

Schizophrenia (SCZ) is a complex psychotic syndrome whose pathogenesis involves countless protagonists, none of which, to date, can fully explain how this disorder develops. In this narrative review, an overview of the biochemical impairment is offered according to several perspectives. Indeed, the metabolic framework behind SCZ dopaminergic hypotheses, glutamate - gamma-amynobutyric acid dysregulation, norepinephrine and serotonin, calcium channel dysfunction is addressed together with the energetic impairment, involving glucose and lipids in SCZ etiopathogenesis, in order to highlight the multilevel pathways affected in this neuropsychiatric disorder. Furthermore, neuroinflammation is analyzed, by virtue of its important role, widely investigated in recent years, in neurodegeneration. Tracing the neurotransmitter activity at the brain level by assessing the metabolic network behind the abovementioned molecules puts into light as unavoidable the need for future studies to adopt an integrate approach to address SCZ pathological and clinical picture. The combination of all these factors, essential in acquiring an overview on the complexity of SCZ pathophysiology represents a crucial step in the development of a more targeted management of SCZ patients.

Investigating bilirubin concentrations in schizophrenia: A systematic review and meta-analysis

Schizophrenia, a severe mental disorder characterized by chronic disability and poor quality of life, has been shown to be associated with alterations in redox balance. Recent research has suggested a potential link between the antioxidant bilirubin and schizophrenia, although findings have been inconsistent. To address this gap, we conducted a systematic review and meta-analysis to evaluate possible alterations in bilirubin concentrations in schizophrenia. A comprehensive search of major databases was conducted to identify articles reporting total and unconjugated bilirubin in schizophrenic patients and healthy controls in case-control studies. Our meta-analysis included 18 studies investigating 16,245 participants. The pooled results did not reveal any significant association between schizophrenia and total bilirubin concentrations. Additionally, such effect was strongly influenced by the results of a single study in sensitivity analysis. Subgroup and meta-regression analyses based on various factors such as study design, sample size, and geographical region showed no significant associations with the effect size, nor they identified sources of heterogeneity. Furthermore, publication bias assessments were conducted to ensure the robustness of the findings. Overall, our findings summarize the available evidence regarding the possible role of bilirubin as a biomarker of schizophrenia and highlight the importance of conducting further research in this area.

The Impact of Childhood Trauma on the Negative Symptoms of Schizophrenia

ABSTRACT

Schizophrenia is a debilitating mental health disorder that imposes profound economic, societal, and personal burdens. The negative symptoms of schizophrenia ( i.e. , blunted affect, alogia, anhedonia, asociality, and avolition) are highly prevalent and pervasive in the psychotic disorder and pose significant resistance to available treatment options. Traumatic childhood experiences are strongly linked with the risk of developing schizophrenia. Most prior studies have primarily focused on positive symptoms of schizophrenia ( e.g. , hallucinations and delusions), whereas less attention has been given to negative symptoms. The current study investigated the relationship between childhood trauma ( i.e. , physical abuse, sexual abuse, and emotional abuse and neglect) and negative symptoms in a sample of schizophrenia outpatients and healthy controls ( n = 159 participants, including 99 patients with schizophrenia). The observations from the current study revealed that schizophrenia patients experienced a significantly greater degree of childhood trauma and negative symptoms than the control individuals. The results of the current study also indicated that more severe experiences of total childhood trauma ( i.e. , summation of all trauma types), physical abuse, and emotional neglect may increase the risk of schizophrenia patients reporting negative symptoms. However, childhood sexual and emotional abuse was found to have no impact on the degree of negative symptoms experienced by schizophrenia patients. Implications and limitations of the current study are discussed. In conclusion, we found that the severity of overall childhood trauma, physical abuse, and emotional neglect may play an important role in increasing the likelihood of schizophrenia patients reporting negative symptoms.

Role of different omics data in the diagnosis of schizophrenia disorder: A machine learning study

Schizophrenia is a serious mental disorder that affects millions of people worldwide. This disorder slowly disintegrates thinking ability and changes behaviours of patients. These patients will show some psychotic symptoms such as hallucinations, delusions, thought disorder and movement disorder. These symptoms are in common with some other psychiatric disorders such as bipolar disorder, major depressive disorder and mood spectrum disorder. As patients would require immediate treatment, an on-time diagnosis is critical. This study explores the use of omics data in diagnosis of schizophrenia. Transcriptome, miRNA and epigenome data are used in diagnosis of patients with schizophrenia with the aid of machine learning algorithms. As the data is in high dimension, mutual information and feature importance are independently used for selecting relevant features for the study. Selected sets of features (biomarkers) are individually used with different machine learning algorithms and their performances are compared to select the best-performing model. This study shows that the top 140 miRNA features selected using mutual information along with support vector machines give the highest accuracy (0.86 ± 0.07) in the diagnosis of schizophrenia. All reported accuracies are validated using 5-fold cross validation. They are further validated using leave one out cross validation and the accuracies are reported in the supplementary material.

Treatment of Cognitive Impairment Associated with Schizophrenia Spectrum Disorders: New Evidence, Challenges, and Future Perspectives

Cognitive impairment associated with schizophrenia (CIAS) represents one of the core features of the disorder and has a significant impact on functional and rehabilitation outcomes of people living with schizophrenia spectrum disorders (SSD). The aim of this critical review is to highlight the most recent evidence on effective treatments available for CIAS, to discuss the current challenges in this field, and to present future perspectives that may help to overcome them. Concerning psychopharmacological approaches, among the most indicated strategies for the management and prevention of CIAS is to favor second-generation antipsychotic medications and avoid long-term and high-dose treatments with anticholinergic medications and benzodiazepines. Moreover, non-pharmacological approaches such as cognitive remediation and physical exercise-based programs represent evidence-based interventions in the treatment of CIAS that have shown reliable evidence of effectiveness on both cognitive and functional outcomes. These treatments, however, are still delivered to people accessing mental health services with a diagnosis of CIAS in an uneven manner, even in high-income countries. Academic and clinical partnership and collaboration, as well as advocacy from service users, families, carers, and stakeholders' organizations could help to reduce the bench to bedside gap in the treatment of CIAS. Future perspectives include the development of novel pharmacological agents that could be effective in the treatment of CIAS, the implementation of novel technologies such as telemedicine and virtual reality in the delivery of evidence-based interventions to improve accessibility and engagement, and further research in the field of non-invasive brain stimulation.

The impact of care-recipient relationship type on mental health burden of caregivers for schizophrenia patients: evidence from Beijing, China

Objective

To examine the impact of care-recipient relationship type on mental health burden of caregivers for schizophrenia patients in China, elucidating the underlying mechanisms.

Methods

A cross-sectional study was conducted using face-to-face surveys administered to caregivers of patients with schizophrenia in selected communities in Beijing, China. 1,853 samples' data was used. Descriptive statistics, logistic regression models and Sheaf coefficient method were employed to analyze the data.

Results

The mental health burden experienced by caregivers of schizophrenia patients has reached a high level, with 66.9% reporting a moderate or severe impact from their caregiving responsibilities. Parents and spouses were the primary providers of care for schizophrenia patients in China. Parent caregivers experienced greater suffering in their caregiving role compared to spouse caregivers, whereas the difference between child caregivers and spouse caregivers was not significant. The factors influencing caregiver's mental health burden vary according to the type of relationship with the care-recipient. For parent caregivers, the mental health burden primarily stems from personal conditions of schizophrenia patients, while for spouse or child caregivers, it mainly arises from family economic conditions.

Conclusion

This study reveals that caregivers having different types of care-recipient relationship with schizophrenia patients experience significantly different mental health burdens in Beijing, China, and major influencing factors are distinct according to different care-recipient relationship types.

Tablet-Based Cognitive and Eye Movement Measures as Accessible Tools for Schizophrenia Assessment: Multisite Usability Study

BACKGROUND

Schizophrenia is a complex mental disorder characterized by significant cognitive and neurobiological alterations. Impairments in cognitive function and eye movement have been known to be promising biomarkers for schizophrenia. However, cognitive assessment methods require specialized expertise. To date, data on simplified measurement tools for assessing both cognitive function and eye movement in patients with schizophrenia are lacking.

OBJECTIVE

This study aims to assess the efficacy of a novel tablet-based platform combining cognitive and eye movement measures for classifying schizophrenia.

METHODS

Forty-four patients with schizophrenia, 67 healthy controls, and 41 patients with other psychiatric diagnoses participated in this study from 10 sites across Japan. A free-viewing eye movement task and 2 cognitive assessment tools (Codebreaker task from the THINC-integrated tool and the CognitiveFunctionTest app) were used for conducting assessments in a 12.9-inch iPad Pro. We performed comparative group and logistic regression analyses for evaluating the diagnostic efficacy of the 3 measures of interest.

RESULTS

Cognitive and eye movement measures differed significantly between patients with schizophrenia and healthy controls (all 3 measures; P<.001). The Codebreaker task showed the highest classification effectiveness in distinguishing schizophrenia with an area under the receiver operating characteristic curve of 0.90. Combining cognitive and eye movement measures further improved accuracy with a maximum area under the receiver operating characteristic curve of 0.94. Cognitive measures were more effective in differentiating patients with schizophrenia from healthy controls, whereas eye movement measures better differentiated schizophrenia from other psychiatric conditions.

CONCLUSIONS

This multisite study demonstrates the feasibility and effectiveness of a tablet-based app for assessing cognitive functioning and eye movements in patients with schizophrenia. Our results suggest the potential of tablet-based assessments of cognitive function and eye movement as simple and accessible evaluation tools, which may be useful for future clinical implementation.

Associations of conservatism and jumping to conclusions biases with aberrant salience and default mode network

AIM

While conservatism bias refers to the human need for more evidence for decision-making than rational thinking expects, the jumping to conclusions (JTC) bias refers to the need for less evidence among individuals with schizophrenia/delusion compared to healthy people. Although the hippocampus-midbrain-striatal aberrant salience system and the salience, default mode (DMN), and frontoparietal networks ("triple networks") are implicated in delusion/schizophrenia pathophysiology, the associations between conservatism/JTC and these systems/networks are unclear.

METHODS

Thirty-seven patients with schizophrenia and 33 healthy controls performed the beads task, with large and small numbers of bead draws to decision (DTD) indicating conservatism and JTC, respectively. We performed independent component analysis (ICA) of resting functional magnetic resonance imaging (fMRI) data. For systems/networks above, we investigated interactions between diagnosis and DTD, and main effects of DTD. We similarly applied ICA to structural and diffusion MRI to explore the associations between DTD and gray/white matter.

RESULTS

We identified a significant main effect of DTD with functional connectivity between the striatum and DMN, which was negatively correlated with delusion severity in patients, indicating that the greater the anti-correlation between these networks, the stronger the JTC and delusion. We further observed the main effects of DTD on a gray matter network resembling the DMN, and a white matter network connecting the functional and gray matter networks (all P < 0.05, family-wise error [FWE] correction). Function and gray/white matter showed no significant interactions.

CONCLUSION

Our results support the novel association of conservatism and JTC biases with aberrant salience and default brain mode.

Abnormal connectivity and activation during audiovisual speech perception in schizophrenia

The unconscious integration of vocal and facial cues during speech perception facilitates face-to-face communication. Recent studies have provided substantial behavioural evidence concerning impairments in audiovisual (AV) speech perception in schizophrenia. However, the specific neurophysiological mechanism underlying these deficits remains unknown. Here, we investigated activities and connectivities centered on the auditory cortex during AV speech perception in schizophrenia. Using magnetoencephalography, we recorded and analysed event-related fields in response to auditory (A: voice), visual (V: face) and AV (voice-face) stimuli in 23 schizophrenia patients (13 males) and 22 healthy controls (13 males). The functional connectivity associated with the subadditive response to AV stimulus (i.e., [AV] < [A] + [V]) was also compared between the two groups. Within the healthy control group, [AV] activity was smaller than the sum of [A] and [V] at latencies of approximately 100 ms in the posterior ramus of the lateral sulcus in only the left hemisphere, demonstrating a subadditive N1m effect. Conversely, the schizophrenia group did not show such a subadditive response. Furthermore, weaker functional connectivity from the posterior ramus of the lateral sulcus of the left hemisphere to the fusiform gyrus of the right hemisphere was observed in schizophrenia. Notably, this weakened connectivity was associated with the severity of negative symptoms. These results demonstrate abnormalities in connectivity between speech- and face-related cortical areas in schizophrenia. This aberrant subadditive response and connectivity deficits for integrating speech and facial information may be the neural basis of social communication dysfunctions in schizophrenia.

Aberrant thalamocortical connectivity and shifts between the resting state and task state in patients with schizophrenia

Prominent pathological hypotheses for schizophrenia include auditory processing deficits and dysconnectivity within cerebral networks. However, most neuroimaging studies have focused on impairments in either resting-state or task-related functional connectivity in patients with schizophrenia. The aims of our study were to examine (1) blood oxygen level-dependent (BOLD) signals during auditory steady-state response (ASSR) tasks, (2) functional connectivity during the resting-state and ASSR tasks and (3) state shifts between the resting-state and ASSR tasks in patients with schizophrenia. To reduce the functional consequences of scanner noise, we employed resting-state and sparse sampling auditory fMRI paradigms in 25 schizophrenia patients and 25 healthy controls. Auditory stimuli were binaural click trains at frequencies of 20, 30, 40 and 80 Hz. Based on the detected ASSR-evoked BOLD signals, we examined the functional connectivity between the thalamus and bilateral auditory cortex during both the resting state and ASSR task state, as well as their alterations. The schizophrenia group exhibited significantly diminished BOLD signals in the bilateral auditory cortex and thalamus during the 80 Hz ASSR task (corrected p < 0.05). We observed a significant inverse relationship between the resting state and ASSR task state in altered functional connectivity within the thalamo-auditory network in schizophrenia patients. Specifically, our findings demonstrated stronger functional connectivity in the resting state (p < 0.004) and reduced functional connectivity during the ASSR task (p = 0.048), which was mediated by abnormal state shifts, within the schizophrenia group. These results highlight the presence of abnormal thalamocortical connectivity associated with deficits in the shift between resting and task states in patients with schizophrenia.

Association between copy number variations in parkin (PRKN) and schizophrenia and autism spectrum disorder: A case-control study

AIM

The present study aimed to examine the association between copy number variations (CNVs) in parkin (PRKN) and schizophrenia (SCZ) and autism spectrum disorder (ASD) in a large case-control sample.

METHOD

Array comparative genomic hybridization was performed on 3111 cases with SCZ, 1236 cases with ASD, and 2713 controls. We systematically prioritized likely pathogenic CNVs (LP-CNVs) in PRKN and examined their association with SCZ and ASD.

RESULTS

In total, 3014 SCZ cases (96.9%), 1205 ASD cases (97.5%), and 2671 controls (98.5%) passed quality control. We found that monoallelic carriers of LP-CNVs in PRKN were common (70/6890, 1.02%) and were not at higher risk of SCZ (p = 0.29) or ASD (p = 0.72). We observed that the distribution pattern of LP-CNVs in the Japanese population was consistent with those in other populations. We also identified a patient diagnosed with SCZ and early-onset Parkinson's disease carrying biallelic pathogenic CNVs in PRKN. The absence of Parkinson's symptoms in 10 other monoallelic carriers of the same pathogenic CNV further reflects the lack of effect of monoallelic pathogenic variants in PRKN in the absence of a second hit.

CONCLUSION

The present findings suggest that monoallelic CNVs in PRKN do not confer a significant risk for SCZ or ASD. However, further studies to investigate the association between biallelic CNVs in PRKN and SCZ and ASD are warranted.

Longitudinal reduction in brain volume in patients with schizophrenia and its association with cognitive function

Establishing a brain biomarker for schizophrenia is strongly desirable not only to support diagnosis by psychiatrists but also to help track the progressive changes in the brain over the course of the illness. A brain morphological signature of schizophrenia was reported in a recent study and is defined by clusters of brain regions with reduced volume in schizophrenia patients compared to healthy individuals. This signature was proven to be effective at differentiating patients with schizophrenia from healthy individuals, suggesting that it is a good candidate brain biomarker of schizophrenia. However, the longitudinal characteristics of this signature have remained unclear. In this study, we examined whether these changes occurred over time and whether they were associated with clinical outcomes. We found a significant change in the brain morphological signature in schizophrenia patients with more brain volume loss than the natural, age-related reduction in healthy individuals, suggesting that this change can capture a progressive morphological change in the brain. We further found a significant association between changes in the brain morphological signature and changes in the full-scale intelligence quotient (IQ). The patients with IQ improvement showed preserved brain morphological signatures, whereas the patients without IQ improvement showed progressive changes in the brain morphological signature, suggesting a link between potential recovery of intellectual abilities and the speed of brain pathology progression. We conclude that the brain morphological signature is a brain biomarker that can be used to evaluate progressive changes in the brain that are associated with cognitive impairment due to schizophrenia.

Aripiprazole 2-month ready-to-use 960 mg (Ari 2MRTU): review of its possible role in schizophrenia therapy

Most patients with schizophrenia need life-long treatment. There is therefore a continued need for effective and tolerable treatment options. A 2-monthly LAI formulation of aripiprazole, Aripiprazole 2-Month Ready-to-Use 960 mg (Ari 2MRTU 960) has recently been approved in the US. Here, the possible role in therapy for this new treatment option is discussed in a narrative review. PubMed was searched for literature on long-acting injectables with a focus on patient-reported outcomes and real-world evidence on extended injection intervals (2-3 months). Dopamine D2 partial agonists, one of which is aripiprazole, exhibit favorable tolerability and safety properties. Additionally, there are many advantages in using long-acting injectable formulations such as enhanced treatment persistence and stability of patients as well as reduced rates of relapses, hospitalizations, and death. Some of these advantages become more pronounced with longer injection intervals. Additional advantages of longer injection intervals are more room for non-medication-related communication between healthcare professionals and patients, patient and physician preferences, reduced caregiver burden, and easier transitioning from inpatient to outpatient treatment. Taken together, since aripiprazole may be a good treatment choice for many patients based on its favorable safety and tolerability profile, and given the advantages of LAI treatment over oral treatment and the advantages of reduced dosing frequency, Ari 2MRTU 960 may become an important treatment option for many clinically stable patients with schizophrenia.

[Autoimmune encephalitis: psychiatric aspects]

Autoimmune encephalitis is a group of diseases researched by both neurologists and psychiatrists. Despite a large number of studies and practical recommendations, the differential diagnosis and early diagnostics still remains an important issue. The most difficult to diagnose are cases that debut as mental disorders and/or occur without neurological symptoms. The literature review presents the current state of the problem with an emphasis on the practice of a psychiatrist.

Subcortical volumetric alterations in four major psychiatric disorders: a mega-analysis study of 5604 subjects and a volumetric data-driven approach for classification

Differential diagnosis is sometimes difficult in practical psychiatric settings, in terms of using the current diagnostic system based on presenting symptoms and signs. The creation of a novel diagnostic system using objective biomarkers is expected to take place. Neuroimaging studies and others reported that subcortical brain structures are the hubs for various psycho-behavioral functions, while there are so far no neuroimaging data-driven clinical criteria overcoming limitations of the current diagnostic system, which would reflect cognitive/social functioning. Prior to the main analysis, we conducted a large-scale multisite study of subcortical volumetric and lateralization alterations in schizophrenia, bipolar disorder, major depressive disorder, and autism spectrum disorder using T1-weighted images of 5604 subjects (3078 controls and 2526 patients). We demonstrated larger lateral ventricles volume in schizophrenia, bipolar disorder, and major depressive disorder, smaller hippocampus volume in schizophrenia and bipolar disorder, and schizophrenia-specific smaller amygdala, thalamus, and accumbens volumes and larger caudate, putamen, and pallidum volumes. In addition, we observed a leftward alteration of lateralization for pallidum volume specifically in schizophrenia. Moreover, as our main objective, we clustered the 5,604 subjects based on subcortical volumes, and explored whether data-driven clustering results can explain cognitive/social functioning in the subcohorts. We showed a four-biotype classification, namely extremely (Brain Biotype [BB] 1) and moderately smaller limbic regions (BB2), larger basal ganglia (BB3), and normal volumes (BB4), being associated with cognitive/social functioning. Specifically, BB1 and BB2-3 were associated with severe and mild cognitive/social impairment, respectively, while BB4 was characterized by normal cognitive/social functioning. Our results may lead to the future creation of novel biological data-driven psychiatric diagnostic criteria, which may be expected to be useful for prediction or therapeutic selection.

Development of the Delusional Interpretation Scale and examination of related variables

Aim

Delusions are a common symptom in schizophrenia. Some scales have been developed to measure delusional tendencies in healthy people, and nonpathological delusional thinking can occur even among these individuals. The existing scales measure the presence and frequency of delusional thoughts, distress levels, and confidence levels. However, these scales are limited because they do not consider the context of the delusions (i.e., where, with whom, and when). In this study, we developed a new scale that presents detailed scenes using illustrations and sentences and measures the tendency toward delusional interpretations.

Methods

Factor analysis was conducted to confirm the factor structure of the new scale. To examine the validity of the scale, we analyzed the correlations between delusional tendencies and related variables and verified the consistency between the current scale and previously developed tools.

Results

Factor analysis confirmed that the new scale has a two-factor structure, including "internal attribution and paranoid tendency" and "external attribution tendency." The new scale was found to have acceptable reliability and validity. The internal attribution and paranoid tendency factor was negatively correlated with self-esteem and decentering. Furthermore, the internal attribution and paranoid tendency factor showed a moderate positive correlation with depressive state and anxiety tendency and a very weak positive correlation with experiences of bullying or harassment.

Conclusion

The correlations between the new scale and related variables confirmed the construct validity and replicated the results reported in previous studies. This new scale enables the measurement of delusional tendencies in healthy subjects based on the social context.

Better adherence to guidelines among psychiatrists providing pharmacological therapy is associated with longer work hours in patients with schizophrenia

Schizophrenia is a psychiatric disorder that is associated with various social dysfunctions, including shorter work hours. To measure the degree to which psychiatrists adhere to guidelines for pharmacological therapy of schizophrenia, we recently developed the individual fitness score (IFS) for adherence among psychiatrists in each patient. However, it remains unclear whether better adherence among psychiatrists is associated with higher patients' social functional outcomes, such as work hours. In this study, we examined the relationship between adherence to guidelines among psychiatrists and work hours in patients with schizophrenia. To evaluate the association between adherence to guidelines for pharmacological therapy among psychiatrists for treating schizophrenia and work hours, we used the IFS and social activity assessment, respectively, in 286 patients with schizophrenia. The correlation between IFS values and work hours was investigated in the patients. The adherence among psychiatrists to guidelines was significantly and positively correlated with work hours in patients with schizophrenia (rho = 0.18, p = 2.15 × 10-3). When we divided the patients into treatment-resistant schizophrenia (TRS) and nontreatment-resistant schizophrenia (non-TRS) groups, most patients with TRS (n = 40) had shorter work hours (0-15 h/week). Even after excluding patients with TRS, the positive correlation between adherence to guidelines among psychiatrists and work hours in patients with non-TRS (n = 246) was still significant (rho = 0.19, p = 3.32 × 10-3). We found that work hours were longer in patients who received the guideline-recommended pharmacotherapy. Our findings suggest that widespread education and training for psychiatrists may be necessary to improve functional outcomes in patients with schizophrenia.

Abnormal phase entrainment of low- and high-gamma-band auditory steady-state responses in schizophrenia

Introduction

Gamma-band oscillatory deficits have attracted considerable attention as promising biomarkers of schizophrenia (SZ). Notably, a reduced auditory steady-state response (ASSR) in the low gamma band (40 Hz) is widely recognized as a robust finding among SZ patients. However, a comprehensive investigation into the potential utility of the high-gamma-band ASSR in detecting altered neural oscillations in SZ has not yet been conducted.

Methods

The present study aimed to assess the ASSR using magnetoencephalography (MEG) data obtained during steady-state stimuli at frequencies of 20, 30, 40, and 80 Hz from 23 SZ patients and 21 healthy controls (HCs). To evaluate the ASSR, we examined the evoked power and phase-locking factor (PLF) in the time-frequency domain for both the primary and secondary auditory cortices. Furthermore, we calculated the phase-locking angle (PLA) to examine oscillatory phase lead or delay in SZ patients. Taking advantage of the high spatial resolution of MEG, we also focused on the hemispheric laterality of low- and high-gamma-band ASSR deficits in SZ.

Results

We found abnormal phase delay in the 40 Hz ASSR within the bilateral auditory cortex of SZ patients. Regarding the 80 Hz ASSR, our investigation identified an aberrant phase lead in the left secondary auditory cortex in SZ, accompanied by reduced evoked power in both auditory cortices.

Discussion

Given that abnormal phase lead on 80 Hz ASSR exhibited the highest discriminative power between HC and SZ, we propose that the examination of PLA in the 80 Hz ASSR holds significant promise as a robust candidate for identifying neurophysiological endophenotypes associated with SZ. Furthermore, the left-hemisphere phase lead observed in the deficits of 80 Hz PLA aligns with numerous prior studies, which have consistently proposed that SZ is characterized by left-lateralized brain dysfunctions.

Effect of education regarding treatment guidelines for schizophrenia and depression on the treatment behavior of psychiatrists: A multicenter study

AIM

This study aims to examine the real-world effectiveness of education regarding clinical guidelines for psychiatric disorders using 'the Effectiveness of guidelines for dissemination and education in psychiatric treatment (EGUIDE)' project.

METHODS

The EGUIDE project is a nationwide prospective implementation study of two clinical practice guidelines, i.e., the Guideline for Pharmacological Therapy of Schizophrenia and the Treatment Guidelines for Major Depressive Disorders, in Japan. Between 2016 and 2019, 782 psychiatrists belonging to 176 hospitals with psychiatric wards participated in the project and attended lectures on clinical practice guidelines. The proportions of guideline-recommended treatments in 7405 patients with schizophrenia and 3794 patients with major depressive disorder at participating hospitals were compared between patients under the care of psychiatrists participating in the project and those not participating in the project. Clinical and prescribing data on the patients discharged from April to September each year from participating hospitals of the project were also analyzed.

RESULTS

The proportions of three quality indicators (antipsychotic monotherapy regardless of whether other psychotropics medication, antipsychotic monotherapy without other psychotropics and no prescription of anxiolytics or hypnotics) for schizophrenia were higher among participating psychiatrists than among nonparticipating psychiatrists. As similar results were obtained in major depressive disorder, the effectiveness of the project for the dissemination of guideline-recommended treatment has been replicated.

CONCLUSION

This strategy of providing education regarding the clinical guidelines for psychiatric disorders was effective in improving the treatment-related behavior of psychiatrists. The use of this education-based strategy might contribute to resolving the mental health treatment gap.

Longitudinal characteristics of insight and clinical factors in patients with schizophrenia

AIMS

Schizophrenia is a psychiatric disorder presenting a lack of insight. Although insight changes over time, longitudinal studies of insight in schizophrenia are scarce. Furthermore, most previous studies on insight and intelligence have not measured full-scale IQ and have not been able to examine the relationship between detailed dimensions of cognitive function and insight. In this study, we assessed insight at two time points and assessed dimensions of cognitive function.

METHODS

A total of 163 patients with schizophrenia participated in the study. We evaluated insight at two time points to understand the patterns of change and examined the association between insight and clinical variables. Additionally, we examined the relationship between the dimensions of cognitive function and insight.

RESULTS

The patients were divided into three groups based on their change in insight over time: stable at a low level of insight (poor insight), stable at a high level of insight (good insight), and changed in insight over time (unstable insight). Those in the poor insight group had lower general intelligence scores than those in the good insight and unstable insight groups. Regarding cognitive function, verbal comprehension was associated with the level of insight at baseline and follow-up. Regarding psychiatric symptoms, the poor insight group exhibited more severe symptoms than the other two groups, especially regarding positive symptoms.

CONCLUSIONS

Our classification of patients based on changes in insight revealed that poor insight patients had impaired cognitive function, especially verbal comprehension, and more severe positive symptoms than good insight or unstable insight patients.

Why mismatch negativity continues to hold potential in probing altered brain function in schizophrenia

The brain potential known as mismatch negativity (MMN) is one of the most studied indices of altered brain function in schizophrenia. This review looks at what has been learned about MMN in schizophrenia over the last three decades and why the level of interest and activity in this field of research remains strong. A diligent consideration of available evidence suggests that MMN can serve as a biomarker in schizophrenia, but perhaps not the kind of biomarker that early research supposed. This review concludes that MMN measurement is likely to be most useful as a monitoring and response biomarker enabling tracking of an underlying pathology and efficacy of interventions, respectively. The role of, and challenges presented by, pre-clinical models is discussed as well as the merits of different methodologies that can be brought to bear in pursuing a deeper understanding of pathophysiology that might explain smaller MMN in schizophrenia.

Deviant spontaneous neural activity as a potential early-response predictor for therapeutic interventions in patients with schizophrenia

Objective

Previous studies have established significant differences in the neuroimaging characteristics between healthy controls (HCs) and patients with schizophrenia (SCZ). However, the relationship between homotopic connectivity and clinical features in patients with SCZ is not yet fully understood. Furthermore, there are currently no established neuroimaging biomarkers available for the diagnosis of SCZ or for predicting early treatment response. The aim of this study is to investigate the association between regional homogeneity and specific clinical features in SCZ patients.

Methods

We conducted a longitudinal investigation involving 56 patients with SCZ and 51 HCs. The SCZ patients underwent a 3-month antipsychotic treatment. Resting-state functional magnetic resonance imaging (fMRI), regional homogeneity (ReHo), support vector machine (SVM), and support vector regression (SVR) were used for data acquisition and analysis.

Results

In comparison to HCs, individuals with SCZ demonstrated reduced ReHo values in the right postcentral/precentral gyrus, left postcentral/inferior parietal gyrus, left middle/inferior occipital gyrus, and right middle temporal/inferior occipital gyrus, and increased ReHo values in the right putamen. It is noteworthy that there was decreased ReHo values in the right inferior parietal gyrus after treatment compared to baseline data.

Conclusion

The observed decrease in ReHo values in the sensorimotor network and increase in ReHo values in the right putamen may represent distinctive neurobiological characteristics of patients with SCZ, as well as a potential neuroimaging biomarker for distinguishing between patients with SCZ and HCs. Furthermore, ReHo values in the sensorimotor network and right putamen may serve as predictive indicators for early treatment response in patients with SCZ.

Structural aging of human neurons is opposite of the changes in schizophrenia

Human mentality develops with age and is altered in psychiatric disorders, though their underlying mechanism is unknown. In this study, we analyzed nanometer-scale three-dimensional structures of brain tissues of the anterior cingulate cortex from eight schizophrenia and eight control cases. The distribution profiles of neurite curvature of the control cases showed a trend depending on their age, resulting in an age-correlated decrease in the standard deviation of neurite curvature (Pearson's r = -0.80, p = 0.018). In contrast to the control cases, the schizophrenia cases deviate upward from this correlation, exhibiting a 60% higher neurite curvature compared with the controls (p = 7.8 × 10-4). The neurite curvature also showed a correlation with a hallucination score (Pearson's r = 0.80, p = 1.8 × 10-4), indicating that neurite structure is relevant to brain function. This report is based on our 3D analysis of human brain tissues over a decade and is unprecedented in terms of the number of cases. We suggest that neurite curvature plays a pivotal role in brain aging and can be used as a hallmark to exploit a novel treatment of schizophrenia.

Combination Psychotropic Use for Schizophrenia With Long-Acting Injectable Antipsychotics and Oral Antipsychotics: A Nationwide Real-World Study in Japan

BACKGROUND

Although several guidelines recommend monotherapy with antipsychotics for the treatment of schizophrenia, patients who receive long-acting injectable antipsychotics (LAIs) are frequently treated with oral antipsychotics (OAPs). In the present study, we investigated the detailed use of psychotropic medications among patients throughout Japan with schizophrenia who received LAIs or OAPs.

METHODS

The present study used data from the project for the Effectiveness of Guidelines for Dissemination and Education in psychiatric treatment from 94 facilities in Japan. The LAI group included patients who received any LAI, and the non-LAI group included patients who took only OAP medications at discharge. The participants of this study were 2518 schizophrenia patients (263 in the LAI group and 2255 in the non-LAI group) who received inpatient treatment and had prescription information at discharge between 2016 and 2020.

RESULTS

This study revealed significantly higher rates of polypharmacy antipsychotics, number of antipsychotics, and chlorpromazine equivalents in the LAI group than in the non-LAI group. In contrast, the LAI group showed lower rate of concomitant use of hypnotic and/or antianxiety medication than the non-LAI group.

CONCLUSIONS

Presenting these real-world clinical results, we want to encourage clinicians to keep monotherapy in mind for the treatment of schizophrenia, especially by reducing concomitant use of antipsychotics in the LAI group and reducing hypnotic and/or antianxiety medication in the non-LAI group.

Gestational Exposure to Haloperidol Changes Cdkn1a and Apaf1 mRNA Expressions in Mouse Hippocampus

BACKGROUND

The onset of schizophrenia is associated with both genetic and environmental risks during brain development. Environmental factors during pregnancy can represent risk factors for schizophrenia, and we have previously reported that several microRNA and mRNA expression changes in fetal brains exposed to haloperidol during pregnancy may be related to the onset of this disease. This study aimed to replicate that research and focused on apoptotic-related gene expression changes.

METHODS

Haloperidol (1mg/kg) or aripiprazole (1mg/kg) was injected into pregnant mice. Using RNA sequencing for the hippocampus of each offspring born from pregnant mice exposed to haloperidol, we analyzed genes identified as changed in our previous report and validated two apoptosis-related genes (Cdkn1a and Apaf1) using quantitative polymerase chain reaction (qPCR) methods. Furthermore, we attempted to elucidate the direct effects of haloperidol and aripiprazole on those mRNA expressions in in vitro experiments.

RESULTS

RNA sequencing successfully replicated 16 up-regulated and 5 down-regulated genes in this study. Of those, up-regulations of Cdkn1a and Apaf1 mRNA expression were successfully validated by direct quantification. Moreover, haloperidol and aripiprazole dose-dependent upregulation of both mRNA expressions were confirmed in a Neuro2a cell line.

CONCLUSIONS

In the hippocampus of offspring, intraperitoneal injection of haloperidol to pregnant mice induced up-regulation of apoptotic genes that representing the phenotypic change without apoptosis. These findings will be useful for understanding the molecular biological mechanisms underlying the effects of antipsychotics on the fetal brain.

A case study of the utilization of clozapine treatment for treatment-resistant schizophrenia associated with 22q11.2 deletion syndrome

BACKGROUND

The optimal treatment strategy for patients with treatment-resistant schizophrenia (TRS) associated with 22q11.2 deletion syndrome (DS) remains a subject of debate.

CASE PRESENTATION

We present the case of a 40-year-old female patient diagnosed with TRS and 22q11.2DS who was effectively treated with clozapine. She was diagnosed with schizophrenia and mild intellectual disability during her adolescence; despite being hospitalized for a period of 10 years beginning in her 30s, she continued to exhibit symptoms of impulsivity, and explosive behavior, requiring periods of isolation. We ultimately decided to switch her medication to clozapine, which was administered with caution and gradually titrated upward, with no discernable adverse effects, resulting in a marked improvement in her symptoms and obviated the need for isolation. Subsequently, the patient's history of congenital heart disease and facial abnormalities prompted initial suspicions of a 22q11.2DS diagnosis, which was subsequently confirmed through genetic testing.

CONCLUSION

Clozapine may serve as an efficacious pharmacological intervention for TRS patients with 22q11.2DS, including those of Asian descent.

Decreased cortical gyrification and surface area in the left medial parietal cortex in patients with treatment-resistant and ultratreatment-resistant schizophrenia

AIM

Validating the vulnerabilities and pathologies underlying treatment-resistant schizophrenia (TRS) is an important challenge in optimizing treatment. Gyrification and surface area (SA), reflecting neurodevelopmental features, have been linked to genetic vulnerability to schizophrenia. The aim of this study was to identify gyrification and SA abnormalities specific to TRS.

METHODS

We analyzed 3T magnetic resonance imaging findings of 24 healthy controls (HCs), 20 responders to first-line antipsychotics (FL-Resp), and 41 patients with TRS, including 19 clozapine responders (CLZ-Resp) and 22 FL- and clozapine-resistant patients (patients with ultratreatment-resistant schizophrenia [URS]). The local gyrification index (LGI) and associated SA were analyzed across groups. Diagnostic accuracy was verified by receiver operating characteristic curve analysis.

RESULTS

Both CLZ-Resp and URS had lower LGI values than HCs (P = 0.041, Hedges g [g_H ] = 0.75; P = 0.013, g_H  = 0.96) and FL-Resp (P = 0.007, g_H  = 1.00; P = 0.002, g_H  = 1.31) in the left medial parietal cortex (Lt-MPC). In addition, both CLZ-Resp and URS had lower SA in the Lt-MPC than FL-Resp (P < 0.001, g_H  = 1.22; P < 0.001, g_H  = 1.75). LGI and SA were positively correlated in non-TRS (FL-Resp) (ρ = 0.64, P = 0.008) and TRS (CLZ-Resp + URS) (ρ = 0.60, P < 0.001). The areas under the receiver operating characteristic curve for non-TRS versus TRS with LGI and SA in the Lt-MPC were 0.79 and 0.85, respectively. SA in the Lt-MPC was inversely correlated with negative symptoms (ρ = -0.40, P = 0.018) and clozapine plasma levels (ρ = -0.35, P = 0.042) in TRS.

CONCLUSION

LGI and SA in the Lt-MPC, a functional hub in the default-mode network, were abnormally reduced in TRS compared with non-TRS. Thus, altered LGI and SA in the Lt-MPC might be structural features associated with genetic vulnerability to TRS.

Drug Attitude and Medication Adherence of Patients with Early Psychosis in South Korea: Mediating Effect of Medication Adherence Self-Efficacy

Purpose

This study examined the mediating effect of medication adherence self-efficacy (MASE) on the relationship between drug attitude (DA) and medication adherence (MA) in patients with early psychosis.

Patients and Methods

A total of 166 patients, aged 20 years or older, and who had received treatment within 5 years of their initial psychotic episode at a University Hospital outpatient center, participated in the study. Data were analyzed using descriptive statistics, t-tests, one-way analysis of variance, Pearson's correlation coefficients, and multiple linear regression. Additionally, a bootstrapping test was conducted to determine the statistical significance of the mediating effect. All study procedures adhered to Strengthening the reporting of observational studies in epidemiology (STROBE) guidelines.

Results

This study found a significant correlation between MA and DA (r=0.393, p<0.001), and between MA and MASE (r=0.697, p<0.001). MASE had a partial mediating effect on the association between DA and MA. The model that integrated both DA and MASE accounted for 53.4% of the variation in MA. Bootstrapping analysis indicated that MASE was a significant partial parameter (lower limit confidence interval [CI] 0.114; upper limit CI 0.356). Further, 64.5% of the study participants were either currently enrolled in college or had higher levels of education.

Conclusion

These findings could potentially lead to a more personalized approach to medication education and adherence, considering the unique DA and MASE of each patient. By identifying the mediating effect of MASE on the relationship between DA and MA, healthcare providers could tailor interventions to enhance the ability of patients with early psychosis to adhere to prescribed medication regimens.

The characteristics of discharge prescriptions including pro re nata psychotropic medications for patients with schizophrenia and major depressive disorder from the survey of the "Effectiveness of guidelines for dissemination and education in psychiatric treatment (EGUIDE)" project

BACKGROUND

Several guidelines recommend monotherapy in pharmacotherapy for schizophrenia and major depressive disorder. The content of regular prescriptions has been reported in several studies, but not enough research has been conducted on the content of pharmacotherapy, including pro re nata (PRN) medications. The purpose of this study was to evaluate the content of pharmacotherapy, including PRN medications, and to clarify the relationship with regular prescriptions.

METHODS

We used data from the "Effectiveness of Guidelines for Dissemination And Education in psychiatric treatment" (EGUIDE) project to investigate the presence or absence of PRN psychotropic medications at discharge for each drug category. We compared the PRN psychotropic prescription ratio at discharge by diagnosis for each drug category. The antipsychotic monotherapy ratio and no prescription ratio of other psychotropics for schizophrenia at discharge and the antidepressant monotherapy ratio and no prescription ratio of other psychotropics for major depressive disorder at discharge were calculated for each regular prescription, including PRN psychotropic medications, as quality indicators (QIs). Spearman's rank correlation test was performed for QI values of regular prescriptions and the QI ratio between regular prescriptions and prescriptions including PRN medications for each diagnosis.

RESULTS

The PRN psychotropic prescription ratio at discharge was 28.7% for schizophrenia and 30.4% for major depressive disorder, with no significant differences by diagnosis. The prescription ratios of PRN antipsychotic medications and PRN antiparkinsonian medications were significantly higher for schizophrenia. The prescription ratios of PRN anxiolytic and hypnotic and PRN antidepressant medications were significantly higher for patients with major depressive disorder. For both schizophrenia and major depressive disorder, the QI was lower for discharge prescriptions, including PRN medications, than for regular prescriptions. QI values for regular prescriptions and the QI ratio were positively correlated.

CONCLUSIONS

Considering PRN psychotropic medications, the monotherapy ratio and no prescription ratio of other psychotropics at discharge decreased in pharmacotherapy for schizophrenia and major depressive disorder. A higher ratio of monotherapy and no prescription of other psychotropics on regular prescriptions may result in less concomitant use of PRN psychotropic medications. Further studies are needed to optimize PRN psychotropic prescriptions.

The effect of ketamine on eye movement characteristics during free-viewing of natural images in common marmosets

Various eye movement abnormalities and impairments in visual information processing have been reported in patients with schizophrenia. Therefore, dysfunction of saccadic eye movements is a potential biological marker for schizophrenia. In the present study, we used a pharmacological model of schizophrenia symptoms in marmosets and compared the eye movement characteristics of marmosets during free-viewing, using an image set identical to those used for human studies. It contains natural and complex images that were randomly presented for 8 s. As a pharmacological model of schizophrenia symptoms, a subanesthetic dose of ketamine was injected intramuscularly for transient and reversible manipulation. Eye movements were recorded and compared under a ketamine condition and a saline condition as a control. The results showed that ketamine affected eye movement characteristics during free-viewing. Saccades amplitude and scanpath length were significantly reduced in the ketamine condition. In addition, the duration of saccades was longer under the ketamine condition than under the saline condition. A similar tendency was observed for the duration of fixations. The number of saccades and fixations tended to decrease in the ketamine condition. The peak saccades velocity also decreased after ketamine injection whereas there was no difference in the main sequence relationship between saccades amplitude and peak velocity. These results suggest that ketamine affected visual exploration but did not affect the oculomotor aspect of saccades in marmosets, consistent with studies in patients with schizophrenia. Therefore, we conclude that the subanesthetic dose of ketamine is a promising pharmacological model of schizophrenia symptoms in common marmosets and can be used in combination with free-viewing paradigms to establish “translatable markers” for schizophrenia in primates.

A Narrative Review of the Effects of Citrus Peels and Extracts on Human Brain Health and Metabolism

As life expectancy increases, age-associated diseases such as Alzheimer's disease (AD) become a major health problem. The onset of AD involves neurological dysfunction due to amyloid-β accumulation, tau hyperphosphorylation, oxidative stress, and neuroinflammation in the brain. In addition, lifestyle-related diseases-such as dyslipidemia, diabetes, obesity, and vascular dysfunction-increase the risk of developing dementia. The world population ages, prompting the development of new strategies to maintain brain health and prevent the onset of dementia in older and preclinical patients. Citrus fruits are abundant polymethoxylated flavone and flavanone sources. Preclinical studies reported that these compounds have neuroprotective effects in models of dementia such as AD. Interestingly, clinical and epidemiological studies appear to support preclinical evidence and show improved cognitive function and reduced associated disease risk in healthy individuals and/or patients. This review summarizes the recent evidence of the beneficial effects of citrus peels and extracts on human cognition and related functions.