Structural variability of the cerebral cortex in schizophrenia and its association with clinical symptoms.

BACKGROUND: Substantial evidence indicates structural abnormalities in the cerebral cortex of patients with schizophrenia (SCZ), although their clinical implications remain unclear. Previous case-control studies have investigated group-level differences in structural abnormalities, although the study design cannot account for interindividual differences. Recent research has focused on the association between the heterogeneity of the cerebral cortex morphometric features and clinical heterogeneity. METHODS: We used neuroimaging data from 420 healthy controls and 695 patients with SCZ from seven studies. Four cerebral cortex measures were obtained: surface area, gray matter volume, thickness, and local gyrification index. We calculated the coefficient of variation (CV) and person-based similarity index (PBSI) scores and performed group comparisons. Associations between the PBSI scores and cognitive functions were evaluated using Spearman's rho test and normative modeling. RESULTS: Patients with SCZ had a greater CV of surface area and cortical thickness than those of healthy controls. All PBSI scores across cortical measures were lower in patients with SCZ than in HCs. In the patient group, the PBSI scores for gray matter volume and all cortical measures taken together positively correlated with the full-scale IQ scores. Patients with deviant PBSI scores for gray matter volume and all cortical measures taken together had lower full-scale IQ scores than those of other patients. CONCLUSIONS: The cerebral cortex in patients with SCZ showed greater regional and global structural variability than that in healthy controls. Patients with deviant similarity of cortical structural profiles exhibited a lower general intelligence than those exhibited by the other patients.

White matter tract alterations in schizophrenia identified by DTI-based probabilistic tractography: a multisite harmonisation study.

INTRODUCTION: It has been suggested that schizophrenia involves dysconnectivity between functional brain regions and also the white matter structural disorganisation. Thus, diffusion tensor imaging (DTI) has widely been used for studying schizophrenia. However, most previous studies have used the region of interest (ROI) based approach. We, therefore, performed the probabilistic tractography method in this study to reveal the alterations of white matter tracts in the schizophrenia brain. METHODS: A total of four different datasets consisted of 189 patients with schizophrenia and 213 healthy controls were investigated. We performed retrospective harmonisation of raw diffusion MRI data by dMRIharmonisation and used the FMRIB Software Library (FSL) for probabilistic tractography. The connectivities between different ROIs were then compared between patients and controls. Furthermore, we evaluated the relationship between the connection probabilities and the symptoms and cognitive measures in patients with schizophrenia. RESULTS: After applying Bonferroni correction for multiple comparisons, 11 different tracts showed significant differences between patients with schizophrenia and healthy controls. Many of these tracts were associated with the basal ganglia or cortico-striatal structures, which aligns with the current literature highlighting striatal dysfunction. Moreover, we found that these tracts demonstrated statistically significant relationships with few cognitive measures related to language, executive function, or processing speed. CONCLUSION: We performed probabilistic tractography using a large, harmonised dataset of diffusion MRI data, which enhanced the statistical power of our study. It is important to note that most of the tracts identified in this study, particularly callosal and cortico-striatal streamlines, have been previously implicated in schizophrenia within the current literature. Further research with harmonised data focusing specifically on these brain regions could be recommended.

Antipsychotic treatment and risk of discontinuation and hospitalization in first-episode schizophrenia: a nationwide population-based study.

BACKGROUND: Current evidence on antipsychotic treatment and risk of psychiatric hospitalization in first-episode schizophrenia (FES) is largely based on the findings from randomized clinical trials (RCTs). However, the generalization of the findings to real-world patients is limited due to inherent caveats of the RCT. We aimed to investigate the treatment discontinuation and risk of psychiatric hospitalization using a nationwide population database. METHODS: The Health Insurance Review Agency database in South Korea was obtained, and the observation period started from 1 January 2009 to 31 December 2016. We defined the maintenance period as the period from 6-month after the diagnosis of schizophrenia, which is utilized for the main results. For a total of 44 396 patients with FES, a within-individual Cox regression model was used to compare the risk of the treatment discontinuation and psychiatric hospitalization. RESULTS: In group comparison, a long-acting injectable (LAI) antipsychotic group was associated with the lowest risk of the treatment discontinuation (0.64, 0.55-0.75) and psychiatric hospitalization (0.29, 0.22-0.38) in comparison with a typical antipsychotic group and no use, respectively. Among individual antipsychotics, the lowest risk of the treatment discontinuation was observed in LAI paliperidone (0.46, 0.37-0.66) compared to olanzapine. Clozapine was found to be the most effective antipsychotic in lowering the risk of psychiatric hospitalization as monotherapy compared to no use (0.23, 0.18-0.31). CONCLUSIONS: In real-world patients with FES, LAI paliperidone and clozapine were associated with low treatment discontinuation and better effectiveness in lowering the risk of psychiatric hospitalization.

Impact of the early phase of the COVID-19 pandemic on the use of mental health services in South Korea: a nationwide, health insurance data-based study.

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic has profoundly affected the utilization of mental health services. Existing evidence investigating this issue at the nationwide level is lacking, and it is uncertain whether the effects of the COVID-19 pandemic on the use of psychiatric services differs based on psychiatric diagnosis. METHODS: Data from the claims database between October 2015 and August 2020 was obtained from the Health Insurance Review and Assessment agency in South Korea. Based on the main diagnostic codes, psychiatric patients were identified and categorized into diagnostic groups (anxiety disorders, bipolar and related disorders, depressive disorders, and schizophrenia spectrum disorders). We calculated the number of psychiatric inpatients and outpatients and the medication adherence of patients for each month. We compared the actual and predicted values of outcomes during the COVID-19 pandemic and performed interrupted time-series analyses to test the statistical significance of the impact of the pandemic. RESULTS: During the COVID-19 pandemic, the number of inpatients and admissions to psychiatric hospitals decreased for bipolar and related disorders and depressive disorders. In addition, the number of patients admitted to psychiatric hospitals for schizophrenia spectrum disorders decreased. The number of psychiatric outpatients showed no significant change in all diagnostic groups. Increased medication adherence was observed for depressive, schizophrenia spectrum, and bipolar and related disorders. CONCLUSIONS: In the early phase of the COVID-19 pandemic, there was a trend of a decreasing number of psychiatric inpatients and increasing medication adherence; however, the number of psychiatric outpatients remained unaltered.

Structural impairment in superficial and deep white matter in schizophrenia.

OBJECTIVE: Although disconnectivity among brain regions has been one of the main hypotheses for schizophrenia, the superficial white matter (SWM) has received less attention in schizophrenia research than the deep white matter (DWM) owing to the challenge of consistent reconstruction across subjects. METHODS: We obtained the diffusion magnetic resonance imaging (dMRI) data of 223 healthy controls and 143 patients with schizophrenia. After harmonising the raw dMRIs from three different studies, we performed whole-brain two-tensor tractography and fibre clustering on the tractography data. We compared the fractional anisotropy (FA) of white matter tracts between healthy controls and patients with schizophrenia. Spearman's rho was adopted for the associations with clinical symptoms measured by the Positive and Negative Syndrome Scale (PANSS). The Bonferroni correction was used to adjust multiple testing. RESULTS: Among the 33 DWM and 8 SWM tracts, patients with schizophrenia had a lower FA in 14 DWM and 4 SWM tracts than healthy controls, with small effect sizes. In the patient group, the FA deviations of the corticospinal and superficial-occipital tracts were negatively correlated with the PANSS negative score; however, this correlation was not evident after adjusting for multiple testing. CONCLUSION: We observed the structural impairments of both the DWM and SWM tracts in patients with schizophrenia. The SWM could be a potential target of interest in future research on neural biomarkers for schizophrenia.

Delay in psychiatric hospitalization from the diagnosis of first-episode schizophrenia and its association with clinical outcomes and direct medical costs: a nationwide, health insurance data-based study.

BACKGROUND: Early intervention is essential for improving the prognosis in patients with first-episode schizophrenia (FES). The Mental Health Act limits involuntary hospitalization in South Korea to cases where an individual exhibits both a mental disorder and a potential for harming themselves or others, which could result in a delay in the required treatment in FES. We investigated the effect of delay in the first psychiatric hospitalization on clinical outcomes in FES. METHODS: The South Korean Health Insurance Review Agency database (2012-2019) was used. We identified 15,994 patients with FES who had a record of at least one psychiatric hospitalization within 1 year from their diagnosis. A multivariate linear regression model and a generalized linear model with a gamma distribution and log link were used to examine associations between the duration from the diagnosis to the first psychiatric admission and clinical outcomes as well as direct medical costs after 2 and 5 years. RESULTS: Within both the 2-year and the 5-year period, longer durations from the diagnosis to the first psychiatric admission were associated with an increase in the number of psychiatric hospitalizations (2-y: B = 0.003, p = 0.003, 5-y: B = 0.007, p = 0.001) and an increase in direct medical costs (total: 2-y: B = 0.005, p < 0.001, 5-y: B = 0.004, p = 0.005; inpatient care: 2-y: B = 0.005, p < 0.001, 5-y: B = 0.004, p = 0.017). CONCLUSIONS: Earlier psychiatric admission from the diagnosis is associated with a decrease in the number of psychiatric admissions as well as in direct medical costs in patients with FES.

Risk of treatment discontinuation and psychiatric hospitalization associated with early dose reduction of antipsychotic treatment in first-episode schizophrenia: A nationwide, health insurance data-based study.

AIM: We investigated the impact of early dose reduction of antipsychotic treatment on the risk of treatment discontinuation and psychiatric hospitalization in patients with first-episode schizophrenia (FES). METHODS: The Health Insurance Review Agency database in South Korea was used to include 16 153 patients with FES. At 6 months from their diagnosis, the patients were categorized by the magnitude of dose reduction (no reduction, 0%-50%, and >50%). With a reference of no reduction, the risk of treatment discontinuation and psychiatric hospitalization associated with dose reduction in the 1-year follow-up period after the first 6 months was examined with a Cox proportional hazard ratio model stratified by the mean daily olanzapine-equivalent dose in the first 3 months (<10, 10 to 20, >20 mg/day). RESULTS: A >50% dose reduction was associated with an increased risk of treatment discontinuation in all subgroups (<10 mg/day: hazard ratio [HR] =1.44, 95% confidence interval [CI] =1.24-1.67 [P <0.01]; 10-20 mg/day: HR =1.60, 95% CI =1.37-1.86 [P <0.01]; and >20 mg/day: HR =1.62, 95% CI =1.37-1.91 [P <0.01]). In the subgroup taking <10 mg/day, an association of 0%-50% dose reduction with an increased risk of treatment discontinuation was observed (HR =1.20, 95% CI =1.09-1.31; P <0.01). A > 50% dose reduction was associated with increased risk of psychiatric hospitalization only in the subgroup taking <10 mg/day (HR =1.48, 95% CI =1.21-1.80; P <0.01). CONCLUSIONS: Our results suggest that an above certain dose of antipsychotic drugs is required to prevent psychiatric hospitalization, and extensive dose reduction of antipsychotic drugs could result in a higher risk of treatment discontinuation.

Effects of comorbid alcohol use disorder on the clinical outcomes of first-episode schizophrenia: a nationwide population-based study.

BACKGROUND: Alcohol use disorder (AUD) is a common psychiatric comorbidity in schizophrenia, associated with poor clinical outcomes and medication noncompliance. Most previous studies on the effect of alcohol use in patients with schizophrenia had limitations of small sample size or a cross-sectional design. Therefore, we used a nationwide population database to investigate the impact of AUD on clinical outcomes of schizophrenia. METHODS: Data from the Health Insurance Review Agency database in South Korea from January 1, 2007 to December 31, 2016 were used. Among 64,442 patients with first-episode schizophrenia, 1598 patients with comorbid AUD were selected based on the diagnostic code F10. We performed between- and within-group analyses to compare the rates of psychiatric admissions and emergency room (ER) visits, and medication possession ratio (MPR) between the patients with comorbid AUD and control patients matched for the onset age, sex, and observation period. RESULTS: The rates of psychiatric admissions and ER visits in both groups decreased after the time point of diagnosis of AUD; however, the decrease was significantly greater in the patients with comorbid AUD compared to the control patients. While the comorbid AUD group showed an increase in MPR after the diagnosis of AUD, MPR decreased in the control group. The rates of psychiatric admissions, ER visits, and MPR were worse in the comorbid AUD group both before and after the diagnosis of AUD. CONCLUSIONS: The results emphasize an importance of psychiatric comorbidities, especially AUD, in first-episode schizophrenia and the necessity of further research for confirmative findings of the association of AUD with clinical outcomes of schizophrenia.

Low white-matter integrity between the left thalamus and inferior frontal gyrus in patients with insomnia disorder

Background: Previous studies have reported functional and structural abnormalities in the thalamus and the pars triangularis of the inferior frontal gyrus in patients with insomnia disorder. However, no studies have been conducted on the white-matter tracts between these 2 brain regions. We aimed to compare the white-matter integrity and structure of the left thalamus­pars triangularis tracts between patients with insomnia and controls, and to characterize the relationship between white-matter integrity and clinical features in patients with insomnia. Methods: In total, 22 participants with insomnia disorder and 27 controls underwent overnight polysomnography and brain magnetic resonance imaging, and then completed self-report clinical questionnaires and neurocognitive tests for spatial planning. Structural and diffusion measures such as fractional anisotropy, axial diffusivity, radial diffusivity and trace were analyzed in group comparison and correlation analyses. Results: The insomnia group showed significantly lower fractional anisotropy (F = 8.647, p = 0.02) and axial diffusivity (F = 5.895, p = 0.038) in the left thalamus­pars triangularis tracts than controls. In patients with insomnia, fractional anisotropy in the tracts was correlated with the results of the Stockings of Cambridge test (r = 0.451, p = 0.034), and radial diffusivity was correlated with Epworth Sleepiness Scale score (r = 0.437, p = 0.042). Limitations: Limitations included analyses of limited brain regions and the cross-sectional design. Conclusion: The insomnia group showed decreased integrity in the left thalamus­pars triangularis tracts, and integrity was correlated with cognition and daytime sleepiness. These results may imply that insomnia is characterized by disintegration of the white-matter tract between the left thalamus and inferior frontal gyrus.

Topological abnormalities of the morphometric similarity network of the cerebral cortex in schizophrenia.

A morphometric similarity (MS) network can be constructed using multiple magnetic resonance imaging parameters of each cortical region. An MS network can be used to assess the similarity between cortical regions. Although MS networks can detect microstructural alterations and capture connections between histologically similar cortical areas, the influence of schizophrenia on the topological characteristics of MS networks remains unclear. We obtained T1- and diffusion-weighted images of 239 healthy controls and 190 individuals with schizophrenia to construct the MS network. Group comparisons of the mean MS of the cortical regions and subnetworks were performed. The strengths of the connections between the cortical regions and the global and nodal network indices were compared between the groups. Clinical associations with the network indices were tested using Spearman's rho. Compared with healthy controls, individuals with schizophrenia had significant group differences in the mean MS of several cortical regions and subnetworks. Individuals with schizophrenia had both superior and inferior strengths of connections between cortical regions compared with those of healthy controls. We observed regional abnormalities of the MS network in individuals with schizophrenia regarding lower centrality values of the pars opercularis, superior frontal, and superior temporal areas. Specific nodal network measures of the right pars opercularis and left superior temporal areas were associated with illness duration in individuals with schizophrenia. We identified regional abnormalities of the MS network in schizophrenia with the left superior temporal area possibly being a key region in topological organization and cortical connections.

Social Stigma Toward Individuals with Schizophrenia in a Lebanese Population.

Background: Schizophrenia has been recognized as the most stigmatized mental disorder, imposing a substantial burden on affected individuals. However, no prior studies have investigated social stigma toward individuals with schizophrenia in Lebanon. Purpose: We aimed to examine three components of social stigma including knowledge, attitude, and behavior toward individuals with schizophrenia in a Lebanese population and to explore associated factors with the level of social stigma. Patients and Methods: A cross-sectional online survey was administered, and data from 469 participants were gathered from January 31, 2023, to February 18, 2023. We used previously validated questionnaires to assess the knowledge, attitude (Social Distance Scale), and behavior (Reported and Intended Behavior Scale) of participants toward individuals with schizophrenia. The score for each section was calculated and used to explore the associations between sociodemographic factors and the levels of stigma in each domain. Results: The study participants had a moderate understanding of schizophrenia. However, a substantial proportion showed negative attitudes and unfavorable behaviors toward individuals with schizophrenia. We identified several sociodemographic factors associated with the knowledge, attitude, and behavior scores. Notably, a higher knowledge score and more positive attitudes were positively correlated with improved intended behaviors. Conclusion: This study highlights the pervasive stigma encompassing issues in knowledge, attitudes, and behavior surrounding schizophrenia in a Lebanese population. Our study suggests a pressing need for targeted interventions to increase public awareness and decrease the social stigma of schizophrenia in Lebanon.

Risk of Breast Cancer in Association with the Use of Second-generation Antipsychotics.

Objective: Previous studies regarding the relationship between the risk of breast cancer (BC) and antipsychotics use have reported inconsistent findings. Insufficient sample size and/or observation period may have hindered revealing the risk of BC associated with antipsychotics use. We aimed to investigate whether the use of second-generation antipsychotics (SGA) is associated with increased risk of BC. Methods: We used the Health Insurance Review Agency database in South Korea between 2008 and 2018. The index date was determined as the date of the first antipsychotic prescription. We selected women prescribed SGAs for more than 30 days within a year from the index date and age-matched controls, yielding 498,970 cases and 997,940 controls. The Cox proportional hazards regression model was used for estimating the risk. Results: The incidence rates of BC were 109.74 and 101.51 per 100,000 person-years in the case and control groups, respectively. There was an increased risk of BC in the case group (hazard ratio [HR] = 1.08, 95% confidence interval [CI] 1.04-1.13). There was a higher risk of BC in subjects prescribed with ≥ 10,000 mg of olanzapine equivalent dose (HR = 1.29, 95% CI 1.14-1.46) than those with < 10,000 mg (HR = 1.05, 95% CI 1.00-1.11). The increased risk of BC in the case group became significant after six years of the observation period (≥ 6 years: HR = 1.24, 95% CI 1.14-1.35, 3 to < 6 years: HR = 1.06, 95% CI 0.97-1.15, < 3 years: HR = 1.02, 95% CI 0.95-1.09). Conclusion: This study indicated that the use of SGAs is associated with increased risk of BC in a long-term relationship with a dose-response pattern.

Comparative effectiveness of antipsychotic monotherapy and polypharmacy in schizophrenia patients with clozapine treatment: A nationwide, health insurance data-based study.

Clozapine is the most effective antipsychotic for treatment-resistant schizophrenia (TRS). However, it remains uncertain whether antipsychotic augmentation to clozapine has the superior effectiveness over clozapine alone and the effect size of clozapine compared to other antipsychotic drugs in TRS. Therefore, we examined the comparative effectiveness of antipsychotic monotherapy and polypharmacy on the risk of psychiatric admission and treatment discontinuation in TRS. Data were collected from the Health Insurance Review Agency database between January 2010 and December 2019 in South Korea. Among prevalent patients with schizophrenia, we defined 22,327 patients with TRS as those who had been prescribed with clozapine at least once during the entire observation period. Stratified Cox proportional hazards regressions were performed using data on all antipsychotic prescriptions of patients with TRS to investigate the risk of psychiatric hospitalization and treatment discontinuation associated with antipsychotic treatment. In individual comparisons, clozapine monotherapy was the most effective for the risk of psychiatric hospitalization compared to no use (hazard ratio [HR] = 0.23, 95% confidence interval [CI] = 0.22-0.25). In group comparisons, clozapine with long-acting injectable (LAI) second-generation antipsychotics (SGA) was superior to clozapine monotherapy for the risk of psychiatric hospitalization (HR = 0.60, 95%CI = 0.41-0.88). Clozapine monotherapy was associated with the lowest risk of treatment discontinuation in the individual and group comparisons. This retrospective observational population-based study reports that clozapine with LAI SGA is more effective in lowering the risk of psychiatric hospitalization in antipsychotic group comparison with the reference of clozapine monotherapy.

Diagnostic conversion from unipolar to bipolar affective disorder-A population-based study.

OBJECTIVES: It is essential to clinically distinguish bipolar affective disorder from unipolar affective disorders. However, patients previously diagnosed with unipolar affective disorder are sometimes later diagnosed with bipolar affective disorder, known as diagnostic conversion. Here we investigated diagnostic conversion using data from a nationwide population-based register. METHODS: We obtained claims data from 2007 to 2020 in Korea's Health Insurance Review Agency database and identified a cohort of patients who were diagnosed with unipolar depression in 2009 without prior psychiatric diseases within the previous 2 years. We studied the rate of diagnostic conversion and risk factors, especially antidepressants. RESULTS: About 6.5% of patients underwent diagnostic conversion during the observation period. Younger age at disease onset and usage of antidepressants increased the relative risk for diagnostic conversion. Patients using serotonin-norepinephrine reuptake inhibitors (SNRI) showed more than twice the risk compared to no usage of antidepressant. LIMITATION: First, this study was based on the population-based register data. Thus, we defined the patient cohort diagnosed with unipolar depression with strict inclusion criteria. Second, the exposure time differed between different antidepressants. Third, we estimated the relative risk for diagnostic conversion compared to no use of antidepressants. Moreover, we could not rule out the potential influence of antidepressant polypharmacy. CONCLUSION: We confirmed diagnostic conversion in some patients and identified younger age or usage of antidepressants, especially SNRI, as risk factors. Because unipolar and bipolar affective disorders show different disease courses or prognoses and have different treatment strategies, clinicians should be mindful of diagnostic conversion.

One-Year Clinical Outcomes Following Electroconvulsive Therapy for Patients with Schizophrenia: A Nationwide Health Insurance Data-Based Study.

Background: Although the use of electroconvulsive therapy (ECT) in the treatment of schizophrenia has decreased since the advent of antipsychotic drugs, ECT is still implemented in several clinical indications. However, a few population-based studies have examined its real-world effectiveness in schizophrenia. Methods: We used data from 2010 to 2019 from the Health Insurance Review and Assessment Service database in the Republic of Korea. We selected 380 schizophrenia patients having more than six ECT sessions and 1140 patient controls matched for age, sex, calendar year at entry, and the number of psychiatric hospitalizations before the time point of start of psychiatric hospitalization for ECT. Antipsychotic treatment discontinuation, psychiatric hospitalization, and direct medical costs were used as measures of clinical outcomes. Multiple regression analysis was used for any group-by-time interaction effect, and 1-year pre- and post-ECT periods were compared within and between the groups. Results: We found a significantly lower number of antipsychotic treatment discontinuations in the ECT group during the 1-year post-ECT period (t=2.195, p=0.028). A larger decrease was found in the number of psychiatric hospitalizations in the ECT group, with a group-by-time interaction effect (p=0.043). The direct medical costs in the 1-year pre- (t=-8.782, p<0.001) and post-ECT periods (t=-9.107, p<0.001) were higher in the ECT group than in the control group, with no significant change across both periods. Conclusion: We found that the ECT group had a larger decrease in the number of psychiatric hospitalizations in the 1-year post-ECT period than the control group.

Factors associated with post-electroconvulsive therapy delirium: A retrospective chart review study.

ABSTRACT: Although electroconvulsive therapy (ECT) is generally a safe therapeutic method, unexpected adverse effects, such as post-ECT delirium, may occur. Despite its harmful consequences, there has been little discussion about the predictors of post-ECT delirium. Thus, the current study aimed to clarify the factors associated with post-ECT delirium by reviewing electronic medical records of 268 bitemporal ECT sessions from December 2006 to July 2018 in a university hospital.Demographic and clinical characteristics of sessions involving patients with or without post-ECT delirium were compared. Multiple logistic regression analysis was applied to analyze the correlation between variables and post-ECT delirium.Post-ECT delirium developed in 23 sessions (8.6%). Of all the demographic and clinical variables measured, only etomidate use was significantly different between delirium-positive and delirium-negative groups after Bonferroni correction. The regression model also indicated that etomidate use to be significantly associated with post-ECT delirium.In this study, etomidate was associated with a higher risk of developing post-ECT delirium, an association that appeared unrelated to other possible measured variables. Practitioners should take into account the risk of post-ECT delirium while choosing anesthetics, so as to prevent early discontinuation before sufficient therapeutic gain is achieved.

Use of olanzapine compared with clozapine for treatment-resistant schizophrenia in a real-world setting: nationwide register-based study.

BACKGROUND: Clozapine is generally considered as the treatment of choice for patients with treatment-resistant schizophrenia (TRS). However, its superiority has recently been questioned because olanzapine has been suggested as non-inferior to clozapine in its effectiveness. AIMS: We aimed to investigate the current status of clozapine prescriptions to identify any disparity between clinical guidelines and real-world practices. METHOD: In this study, we utilised the Health Insurance Review Agency database in the Republic of Korea to investigate the real-world effectiveness of clozapine for patients with TRS. We compared differences in patient variables before and after clozapine administration, and we also performed survival analyses for both psychiatric admissions and emergency room visits among patients who used clozapine or olanzapine. RESULTS: This study investigated an incident cohort of 64 442 patients, and 2338 patients have been prescribed clozapine. Of these, 998 patients had TRS. In survival analysis, clozapine showed a worse survival rate for psychiatric admissions than olanzapine (hazard ratio 0.615). We also identified that clinicians tended to try a number of antipsychotics, as recommended, before starting patients on clozapine. CONCLUSIONS: In conclusion, we found that olanzapine led to higher survival rates for psychiatric admissions than clozapine. Thus, considering the risk of serious adverse effects, clozapine may be used conservatively. Considering several studies advocating superior efficacy of clozapine, further studies with extensive data are recommended.

Shared and distinct white matter abnormalities in schizophrenia and bipolar disorder.

While white matter impairments play an integral part in the pathophysiology of schizophrenia and bipolar disorder, the literature on white matter abnormality differences between the two disorders is insufficient. The University of California Los Angeles Consortium for Neuropsychiatric Phenomic LA5c public dataset, including 47 patients with schizophrenia, 47 with bipolar disorder, and 115 healthy controls, was obtained via OpenNeuro. Whole-brain tractography was performed using Unscented Kalman filter-based two-tensor tractography and White Matter Query Language. Diffusion indices, including fractional anisotropy (FA), axial diffusivity, radial diffusivity (RD), and trace (TR), were used to compare subject groups. Spearman's partial correlation with a covariate of age was used for correlation with clinical variables. Both patient groups exhibited significantly higher RD in the left external capsule and TR in the right extreme capsule. Significantly lower FA in the left external capsule, right thalamo-occipital and thalamo-parietal tracts were found in the schizophrenia group in comparison with bipolar disorder and healthy control groups. Compared with healthy controls, patients with schizophrenia had significantly lower FA in the left-to-right lateral orbitofrontal commissural tract. There were possible associations of the FA and RD of the left external capsule with the anxiety-depression score of the Brief Psychiatric Rating Scale in patients with schizophrenia. The white matter alterations identified in schizophrenia and bipolar disorder may be a neurobiological basis contributing to characterization of the two disorders.

White matter impairments in patients with schizophrenia: A multisite diffusion MRI study.

There is a lack of convincing and replicative findings regarding white matter abnormalities in schizophrenia. Several multisite diffusion magnetic resonance imaging (dMRI) studies have been conducted to increase statistical power and reveal subtle white matter changes. Data pooling methods are crucial in joint analysis to compensate for the use of different scanners and image acquisition parameters. A harmonization method using raw dMRI data was developed to overcome the limited generalizability of previous data pooling methods. We obtained dMRI data of 242 healthy controls and 190 patients with schizophrenia from four different study sites. After applying the harmonization method to the raw dMRI data, a two-tensor whole-brain tractography was performed, and diffusion measures were compared between the two groups. The correlation of fractional anisotropy (FA) with the positive and negative symptoms was evaluated, and the interaction effect of diagnosis-by-age, age-squared, and sex was examined. The following white matter tracts showed significant group differences in the FA: the right superior longitudinal fascicle (SLF), the left-to-right lateral orbitofrontal commissural tract, pars orbitalis (pOr-pOr) commissural tract, and pars triangularis (pTr-pTr) commissural tract. The FA of the right SLF and pTr-pTr commissural tract were significantly associated with the Positive and Negative Syndrome Scale (PANSS) positive and negative scores. No significant interaction effect was observed. These findings add to the evidence on structural brain abnormalities in schizophrenia and can aid in obtaining a better understanding of the biological foundations of schizophrenia.

Aberrant Executive Control and Auditory Networks in Recent-Onset Schizophrenia.

PURPOSE: Despite a large number of resting-state functional MRI (rsfMRI) studies in schizophrenia, current evidence on the abnormalities of functional connectivity (FC) of resting-state networks shows high variability, and the findings on recent-onset schizophrenia are insufficient compared to those on chronic schizophrenia. PATIENTS AND METHODS: We performed a rsfMRI in 46 patients with recent-onset schizophrenia and 22 healthy controls. Group independent component brainmap and dual regression were performed for voxel-wise comparisons between the groups. Correlation of the symptom severity, cognitive function, duration of illness, and a total antipsychotics dose with FC was evaluated with Spearman's rho correlation. RESULTS: The patient group had areas with a significantly decreased FC compared to that of the control group in which it existed in the left supplementary motor cortex and supramarginal gyrus (the executive control network) and the right postcentral gyrus (the auditory network). The patient group had a significant correlation of the total antipsychotics dose with the FC of the cluster in the left supplementary motor cortex in the executive control network. CONCLUSION: Patients with recent-onset schizophrenia have decreased FC of the executive control and auditory networks compared to healthy controls.