Rethinking schizophrenia. Nature. 2010;468:187-193. [PMID: 21068826 DOI: 10.1038/nature09552]

Visual system assessment for predicting a transition to psychosis

The field of psychiatry is far from perfect in predicting which individuals will transition to a psychotic disorder. Here, we argue that visual system assessment can help in this regard. Such assessments have generated medium-to-large group differences with individuals prior to or near the first psychotic episode or have shown little influence of illness duration in larger samples of more chronic patients. For example, self-reported visual perceptual distortions-so-called visual basic symptoms-occur in up to 2/3rds of those with non-affective psychosis and have already longitudinally predicted an impending onset of schizophrenia. Possibly predictive psychophysical markers include enhanced contrast sensitivity, prolonged backward masking, muted collinear facilitation, reduced stereoscopic depth perception, impaired contour and shape integration, and spatially restricted exploratory eye movements. Promising brain-based markers include visual thalamo-cortical hyperconnectivity, decreased occipital gamma band power during visual detection (MEG), and reduced visually evoked occipital P1 amplitudes (EEG). Potentially predictive retinal markers include diminished cone a- and b-wave amplitudes and an attenuated photopic flicker response during electroretinography. The foregoing assessments are often well-described mechanistically, implying that their findings could readily shed light on the underlying pathophysiological changes that precede or accompany a transition to psychosis. The retinal and psychophysical assessments in particular are inexpensive, well-tolerated, easy to administer, and brief, with few inclusion/exclusion criteria. Therefore, across all major levels of analysis-from phenomenology to behavior to brain and retinal functioning-visual system assessment could complement and improve upon existing methods for predicting which individuals go on to develop a psychotic disorder.

Schizophrenia: A Narrative Review of Etiopathogenetic, Diagnostic and Treatment Aspects

Although schizophrenia is currently conceptualized as being characterized as a syndrome that includes a collection of signs and symptoms, there is strong evidence of heterogeneous and complex underpinned etiological, etiopathogenetic, and psychopathological mechanisms, which are still under investigation. Therefore, the present viewpoint review is aimed at providing some insights into the recently investigated schizophrenia research fields in order to discuss the potential future research directions in schizophrenia research. The traditional schizophrenia construct and diagnosis were progressively revised and revisited, based on the recently emerging neurobiological, genetic, and epidemiological research. Moreover, innovative diagnostic and therapeutic approaches are pointed to build a new construct, allowing the development of better clinical and treatment outcomes and characterization for schizophrenic individuals, considering a more patient-centered, personalized, and tailored-based dimensional approach. Further translational studies are needed in order to integrate neurobiological, genetic, and environmental studies into clinical practice and to help clinicians and researchers to understand how to redesign a new schizophrenia construct.

Associations of cognitive impairment in patients with schizophrenia with genetic features and with schizophrenia-related structural and functional brain changes

Cognitive impairment is highly prevalent in patients with major psychiatric disorders (MPDs), including schizophrenia (SCZ), bipolar disorder, major depressive disorder, in whom it can be highly disruptive to community functioning and worsen prognosis. Previously, genetic factors and cognitive impairments in MPD patients have been examined mostly in isolated circuits rather than in the whole brain. In the present study, genetic, neuroimaging, and psychometric approaches were combined to investigate the relationship among genetic factors, alterations throughout the brain, and cognitive impairments in a large cohort of patients diagnosed with SCZ, with a reference healthy control (HC) group. Single nucleotide polymorphisms (SNPs) in SCZ-risk genes were found to be strongly related to cognitive impairments as well as to gray matter volume (GMV) and functional connectivity (FC) alterations in the SCZ group. Annotating 136 high-ranking SNPs revealed 65 affected genes (including PPP1R16B, GBBR2, PDE4B, CANCNA1C, SLC12AB, SATB2, MAG12, and SATB2). Only one, a PDE4B SNP (rs1006737), correlated with GMV (r = 0:19 p = 0.015) and FC (r = 0.21, p = 0.0074) in SCZ patients. GMV and FC alterations correlated with one another broadly across brain regions. Moreover, the present data demonstrate three-way SNP-FC-GMV associations in patients with SCZ, thus providing clues regarding potential genetic bases of cognition impairments in SCZ. SNP-FC-GMV relationships correlated with visual learning and reasoning dimensions of cognition. These data provide evidence that SCZ-related cognitive impairments may reflect genetically underlain whole-brain structural and functional alterations.

Temporal-spatial dynamic functional connectivity analysis in schizophrenia classification

With the development of resting-state functional magnetic resonance imaging (rs-fMRI) technology, the functional connectivity network (FCN) which reflects the statistical similarity of temporal activity between brain regions has shown promising results for the identification of neuropsychiatric disorders. Alteration in FCN is believed to have the potential to locate biomarkers for classifying or predicting schizophrenia (SZ) from healthy control. However, the traditional FCN analysis with stationary assumption, i.e., static functional connectivity network (SFCN) at the time only measures the simple functional connectivity among brain regions, ignoring the dynamic changes of functional connectivity and the high-order dynamic interactions. In this article, the dynamic functional connectivity network (DFCN) is constructed to delineate the characteristic of connectivity variation across time. A high-order functional connectivity network (HFCN) designed based on DFCN, could characterize more complex spatial interactions across multiple brain regions with the potential to reflect complex functional segregation and integration. Specifically, the temporal variability and the high-order network topology features, which characterize the brain FCNs from region and connectivity aspects, are extracted from DFCN and HFCN, respectively. Experiment results on SZ identification prove that our method is more effective (i.e., obtaining a significantly higher classification accuracy, 81.82%) than other competing methods. Post hoc inspection of the informative features in the individualized classification task further could serve as the potential biomarkers for identifying associated aberrant connectivity in SZ.

Superior temporal gyrus functional connectivity predicts transcranial direct current stimulation response in Schizophrenia: A machine learning study

Transcranial direct current stimulation (tDCS) is a promising adjuvant treatment for persistent auditory verbal hallucinations (AVH) in Schizophrenia (SZ). Nonetheless, there is considerable inter-patient variability in the treatment response of AVH to tDCS in SZ. Machine-learned models have the potential to predict clinical response to tDCS in SZ. This study aims to examine the feasibility of identifying SZ patients with persistent AVH (SZ-AVH) who will respond to tDCS based on resting-state functional connectivity (rs-FC). Thirty-four SZ-AVH patients underwent resting-state functional MRI at baseline followed by add-on, twice-daily, 20-min sessions with tDCS (conventional/high-definition) for 5 days. A machine learning model was developed to identify tDCS treatment responders based on the rs-FC pattern, using the left superior temporal gyrus (LSTG) as the seed region. Functional connectivity between LSTG and brain regions involved in auditory and sensorimotor processing emerged as the important predictors of the tDCS treatment response. L1-regularized logistic regression model had an overall accuracy of 72.5% in classifying responders vs. non-responders. This model outperformed the state-of-the-art convolutional neural networks (CNN) model-both without (59.41%) and with pre-training (68.82%). It also outperformed the L1-logistic regression model trained with baseline demographic features and clinical scores of SZ patients. This study reports the first evidence that rs-fMRI-derived brain connectivity pattern can predict the clinical response of persistent AVH to add-on tDCS in SZ patients with 72.5% accuracy.

Olfactory impairment in psychiatric disorders: Does nasal inflammation impact disease psychophysiology?

Olfactory impairments contribute to the psychopathology of mental illnesses such as schizophrenia and depression. Recent neuroscience research has shed light on the previously underappreciated olfactory neural circuits involved in regulation of higher brain functions. Although environmental factors such as air pollutants and respiratory viral infections are known to contribute to the risk for psychiatric disorders, the role of nasal inflammation in neurobehavioral outcomes and disease pathophysiology remains poorly understood. Here, we will first provide an overview of published findings on the impact of nasal inflammation in the olfactory system. We will then summarize clinical studies on olfactory impairments in schizophrenia and depression, followed by preclinical evidence on the neurobehavioral outcomes produced by olfactory dysfunction. Lastly, we will discuss the potential impact of nasal inflammation on brain development and function, as well as how we can address the role of nasal inflammation in the pathophysiological mechanisms underlying psychiatric disorders. Considering the current outbreak of Coronavirus Disease 2019 (COVID-19), which often causes nasal inflammation and serious adverse effects for olfactory function that might result in long-lasting neuropsychiatric sequelae, this line of research is particularly critical to understanding of the potential significance of nasal inflammation in the pathophysiology of psychiatric disorders.

Optical coherence tomography reveals retinal thinning in schizophrenia spectrum disorders

BACKGROUND

Schizophrenia spectrum disorders (SSDs) are presumed to be associated with retinal thinning. However, evidence is lacking as to whether these retinal alterations reflect a disease-specific process or are rather a consequence of comorbid diseases or concomitant microvascular impairment.

METHODS

The study included 126 eyes of 65 patients with SSDs and 143 eyes of 72 healthy controls. We examined macula and optic disc measures by optical coherence tomography (OCT) and OCT angiography (OCT-A). Additive mixed models were used to assess the impact of SSDs on retinal thickness and perfusion and to explore the association of retinal and clinical disease-related parameters by controlling for several ocular and systemic covariates (age, sex, spherical equivalent, intraocular pressure, body mass index, diabetes, hypertension, smoking status, and OCT signal strength).

RESULTS

OCT revealed significantly lower parafoveal macular, macular ganglion cell-inner plexiform layer (GCIPL), and macular retinal nerve fiber layer (RNFL) thickness and thinner mean and superior peripapillary RNFL in SSDs. In contrast, the applied OCT-A investigations, which included macular and peripapillary perfusion density, macular vessel density, and size of the foveal avascular zone, did not reveal any significant between-group differences. Finally, a longer duration of illness and higher chlorpromazine equivalent doses were associated with lower parafoveal macular and macular RNFL thickness.

CONCLUSIONS

This study strengthens the evidence for disease-related retinal thinning in SSDs.

Low income and schizophrenia risk: a narrative review

Despite decades of research, the precise etiology of schizophrenia is not fully understood. Ample evidence indicates that the disorder derives from a complex interplay of genetic and environmental factors during vulnerable stages of brain maturation. Among the plethora of risk factors investigated, stress, pre- and perinatal insults, and cannabis use have been repeatedly highlighted as crucial environmental risk factors for schizophrenia. Compelling findings from population-based longitudinal studies suggest low income as an additional risk factor for future schizophrenia diagnosis, but underlying mechanisms remain unclear. In this narrative review, we 1) summarize the literature in support of a relationship between low (parental) income and schizophrenia risk, and 2) explore the mediating role of chronic stress, pre- and perinatal factors, and cannabis use as established risk factors for schizophrenia. Our review describes how low income facilitates the occurrence and severity of these established risk factors and thus contributes to schizophrenia liability. The broadest influence of low income was identified for stress, as low income was found to be associated with exposure to a multitude of severe psychological and physiological stressors. This narrative review adds to the growing literature reporting a close relationship between income and mental health.

Impaired migration of autologous induced neural stem cells from patients with schizophrenia and implications for genetic risk for psychosis

Stem cell technologies have presented explicit evidence of the neurodevelopmental hypothesis of schizophrenia. However, few studies investigated relevance of the schizophrenia genetic liability and the use of genetic reprogramming on pluripotent stem cells to the impaired neurodevelopment shown by stem cells. Therefore, this study sought to investigate the cellular phenotypes of induced neural stem cells (iNSCs) derived without genetic modification from patients with schizophrenia and from genetic high risk (GHR) individuals. Three patients with a diagnosis of schizophrenia, 3 GHR individuals who had two or more relatives with schizophrenia, and 3 healthy volunteers participated. iNSCs were derived using a small molecule-based lineage switch method, and their gene expression levels and migration capabilities were examined. Demographic characteristics were not different among the groups (age, χ² = 5.637, P = .060; education, χ² = 2.111, P = .348). All participants stayed well during the follow-up except one GHR individual who developed psychosis 1.5 years later. Migration capacity was impaired in iNSCs from patients with schizophrenia (SZ-iNSCs) compared to iNSCs from GHR individuals or controls (P < .001). iNSCs from a GHR individual who later developed schizophrenia showed migratory impairment that was similar to SZ-iNSCs. Gene expression levels of Sox2 in SZ-iNSCs were significantly lower than those in controls (P = .028). Defective migration in genetically unmodified SZ-iNSCs is the first direct demonstration of neurodevelopmental abnormalities in schizophrenia. Additionally, alterations in gene expression in SZ-iNSCs suggest mechanisms by which genetic liability leads to aberrant neurodevelopment.

Investigating the Role of GABA in Neural Development and Disease Using Mice Lacking GAD67 or VGAT Genes

Normal development and function of the central nervous system involves a balance between excitatory and inhibitory neurotransmission. Activity of both excitatory and inhibitory neurons is modulated by inhibitory signalling of the GABAergic and glycinergic systems. Mechanisms that regulate formation, maturation, refinement, and maintenance of inhibitory synapses are established in early life. Deviations from ideal excitatory and inhibitory balance, such as down-regulated inhibition, are linked with many neurological diseases, including epilepsy, schizophrenia, anxiety, and autism spectrum disorders. In the mammalian forebrain, GABA is the primary inhibitory neurotransmitter, binding to GABA receptors, opening chloride channels and hyperpolarizing the cell. We review the involvement of down-regulated inhibitory signalling in neurological disorders, possible mechanisms for disease progression, and targets for therapeutic intervention. We conclude that transgenic models of disrupted inhibitory signalling—in GAD67^+/− and VGAT^−/− mice—are useful for investigating the effects of down-regulated inhibitory signalling in a range of neurological diseases.

Developmental influences on symptom expression in antipsychotic-naïve first-episode psychosis

BACKGROUND

The neurodevelopmental model of psychosis was established over 30 years ago; however, the developmental influence on psychotic symptom expression - how age affects clinical presentation in first-episode psychosis - has not been thoroughly investigated.

METHODS

Using generalized additive modeling, which allows for linear and non-linear functional forms of age-related change, we leveraged symptom data from a large sample of antipsychotic-naïve individuals with first-episode psychosis (N = 340, 12-40 years, 1-12 visits), collected at the University of Pittsburgh from 1990 to 2017. We examined relationships between age and severity of perceptual and non-perceptual positive symptoms and negative symptoms. We tested for age-associated effects on change in positive or negative symptom severity following baseline assessment and explored the time-varying relationship between perceptual and non-perceptual positive symptoms across adolescent development.

RESULTS

Perceptual positive symptom severity significantly decreased with increasing age (F = 7.0, p = 0.0007; q = 0.003) while non-perceptual positive symptom severity increased with age (F = 4.1, p = 0.01, q = 0.02). Anhedonia severity increased with increasing age (F = 6.7, p = 0.00035; q = 0.0003), while flat affect decreased in severity with increased age (F = 9.8, p = 0.002; q = 0.006). Findings remained significant when parental SES, IQ, and illness duration were included as covariates. There were no developmental effects on change in positive or negative symptom severity (all p > 0.25). Beginning at age 18, there was a statistically significant association between severity of non-perceptual and perceptual symptoms. This relationship increased in strength throughout adulthood.

CONCLUSIONS

These findings suggest that as maturation proceeds, perceptual symptoms attenuate while non-perceptual symptoms are enhanced. Findings underscore how pathological brain-behavior relationships vary as a function of development.

WHODAS 2.0: Associations of functional disability with sex, age, and length of care in outpatients with schizophrenia-spectrum disorders

Schizophrenia is a disabling mental disorder that is associated with impairments in both social and occupational functioning. Few studies, however, have explored functional domains of disability and its associations with age, sex, and length of care. As part of a hospital quality improvement initiative, data were collected on outpatients' age, sex, length of care, and levels of disability (using the WHODAS 2.0; N=180; M=45.72; 68% male). Mean disability summary and domain scores were compared with population norms from international samples and two published studies in schizophrenia. A series of three-way ANOVAs and post-hoc tests evaluated differences in levels of disability based on age, sex, and length of care categories. Sample mean summary scores were comparable to published studies in schizophrenia (M=24.81; SD=17.37; 85^th percentile). Statistically significant main effects of sex and age on summary and domain-specific scores were found, whereas length of care was not significant. A statistically significant three-way interaction of sex x length of care x age was found for summary and mobility scores. Findings provide support for the reliability and validity of the WHODAS 2.0 in outpatients with schizophrenia. Although causal inferences cannot be made, findings show that age and sex are important factors to consider in addressing disability.

Exploring Brain Structural and Functional Biomarkers in Schizophrenia via Brain-Network-Constrained Multi-View SCCA

Recent studies have proved that dynamic regional measures extracted from the resting-state functional magnetic resonance imaging, such as the dynamic fractional amplitude of low-frequency fluctuation (d-fALFF), could provide a great insight into brain dynamic characteristics of the schizophrenia. However, the unimodal feature is limited for delineating the complex patterns of brain deficits. Thus, functional and structural imaging data are usually analyzed together for uncovering the neural mechanism of schizophrenia. Investigation of neural function-structure coupling enables to find the potential biomarkers and further helps to understand the biological basis of schizophrenia. Here, a brain-network-constrained multi-view sparse canonical correlation analysis (BN-MSCCA) was proposed to explore the intrinsic associations between brain structure and dynamic brain function. Specifically, the d-fALFF was first acquired based on the sliding window method, whereas the gray matter map was computed based on voxel-based morphometry analysis. Then, the region-of-interest (ROI)-based features were extracted and further selected by performing the multi-view sparse canonical correlation analysis jointly with the diagnosis information. Moreover, the brain-network-based structural constraint was introduced to prompt the detected biomarkers more interpretable. The experiments were conducted on 191 patients with schizophrenia and 191 matched healthy controls. Results showed that the BN-MSCCA could identify the critical ROIs with more sparse canonical weight patterns, which are corresponding to the specific brain networks. These are biologically meaningful findings and could be treated as the potential biomarkers. The proposed method also obtained a higher canonical correlation coefficient for the testing data, which is more consistent with the results on training data, demonstrating its promising capability for the association identification. To demonstrate the effectiveness of the potential clinical applications, the detected biomarkers were further analyzed on a schizophrenia-control classification task and a correlation analysis task. The experimental results showed that our method had a superior performance with a 5-8% increment in accuracy and 6-10% improvement in area under the curve. Furthermore, two of the top-ranked biomarkers were significantly negatively correlated with the positive symptom score of Positive and Negative Syndrome Scale (PANSS). Overall, the proposed method could find the association between brain structure and dynamic brain function, and also help to identify the biological meaningful biomarkers of schizophrenia. The findings enable our further understanding of this disease.

Application of positron emission tomography in psychiatry-methodological developments and future directions

Mental disorders represent an increasing source of disability and high costs for societies globally. Molecular imaging techniques such as positron emission tomography (PET) represent powerful tools with the potential to advance knowledge regarding disease mechanisms, allowing the development of new treatment approaches. Thus far, most PET research on pathophysiology in psychiatric disorders has focused on the monoaminergic neurotransmission systems, and although a series of discoveries have been made, the results have not led to any material changes in clinical practice. We outline areas of methodological development that can address some of the important obstacles to fruitful progress. First, we point towards new radioligands and targets that can lead to the identification of processes upstream, or parallel to disturbances in monoaminergic systems. Second, we describe the development of new methods of PET data quantification and PET systems that may facilitate research in psychiatric populations. Third, we review the application of multimodal imaging that can link molecular imaging data to other aspects of brain function, thus deepening our understanding of disease processes. Fourth, we highlight the need to develop imaging study protocols to include longitudinal and interventional paradigms, as well as frameworks to assess dimensional symptoms such that the field can move beyond cross-sectional studies within current diagnostic boundaries. Particular effort should be paid to include also the most severely ill patients. Finally, we discuss the importance of harmonizing data collection and promoting data sharing to reach the desired sample sizes needed to fully capture the phenotype of psychiatric conditions.

Elevated brain-derived cell-free DNA among patients with first psychotic episode - a proof-of-concept study

Schizophrenia is a common, severe, and debilitating psychiatric disorder. Despite extensive research there is as yet no biological marker that can aid in its diagnosis and course prediction. This precludes early detection and intervention. Imaging studies suggest brain volume loss around the onset and over the first few years of schizophrenia, and apoptosis has been proposed as the underlying mechanism. Cell-free DNA (cfDNA) fragments are released into the bloodstream following cell death. Tissue-specific methylation patterns allow the identification of the tissue origins of cfDNA. We developed a cocktail of brain-specific DNA methylation markers, and used it to assess the presence of brain-derived cfDNA in the plasma of patients with a first psychotic episode. We detected significantly elevated neuron- (p=0.0013), astrocyte- (p=0.0016), oligodendrocyte- (p=0.0129), and whole brain-derived (p=0.0012) cfDNA in the plasma of patients during their first psychotic episode (n=29), compared with healthy controls (n=31). Increased cfDNA levels were not correlated with psychotropic medications use. Area under the curve (AUC) was 0.77, with 65% sensitivity at 90% specificity in patients with a psychotic episode. Potential interpretations of these findings include increased brain cell death, disruption of the blood-brain barrier, or a defect in clearance of material from dying brain cells. Brain-specific cfDNA methylation markers can potentially assist early detection and monitoring of schizophrenia and thus allow early intervention and adequate therapy.

Machine Learning Algorithm-Based Prediction Model for the Augmented Use of Clozapine with Electroconvulsive Therapy in Patients with Schizophrenia

The augmentation of clozapine with electroconvulsive therapy (ECT) has been an optimal treatment option for patients with treatment- or clozapine-resistant schizophrenia. Using data from the Research on Asian Psychotropic Prescription Patterns for Antipsychotics survey, which was the largest international psychiatry research collaboration in Asia, our study aimed to develop a machine learning algorithm-based substantial prediction model for the augmented use of clozapine with ECT in patients with schizophrenia in terms of precision medicine. A random forest model and least absolute shrinkage and selection operator (LASSO) model were used to develop a substantial prediction model for the augmented use of clozapine with ECT. Among the 3744 Asian patients with schizophrenia, those treated with a combination of clozapine and ECT were characterized by significantly greater proportions of females and inpatients, a longer duration of illness, and a greater prevalence of negative symptoms and social or occupational dysfunction than those not treated. In the random forest model, the area under the curve (AUC), which was the most preferred indicator of the prediction model, was 0.774. The overall accuracy was 0.817 (95% confidence interval, 0.793−0.839). Inpatient status was the most important variable in the substantial prediction model, followed by BMI, age, social or occupational dysfunction, persistent symptoms, illness duration > 20 years, and others. Furthermore, the AUC and overall accuracy of the LASSO model were 0.831 and 0.644 (95% CI, 0.615−0.672), respectively. Despite the subtle differences in both AUC and overall accuracy of the random forest model and LASSO model, the important variables were commonly shared by the two models. Using the machine learning algorithm, our findings allow the development of a substantial prediction model for the augmented use of clozapine with ECT in Asian patients with schizophrenia. This substantial prediction model can support further studies to develop a substantial prediction model for the augmented use of clozapine with ECT in patients with schizophrenia in a strict epidemiological context.

Different Frequency of Heschl’s Gyrus Duplication Patterns in Neuropsychiatric Disorders: An MRI Study in Bipolar and Major Depressive Disorders

An increased prevalence of duplicated Heschl’s gyrus (HG) has been repeatedly demonstrated in various stages of schizophrenia as a potential neurodevelopmental marker, but it remains unknown whether other neuropsychiatric disorders also exhibit this macroscopic brain feature. The present magnetic resonance imaging study aimed to examine the disease specificity of the established finding of altered HG patterns in schizophrenia by examining independent cohorts of bipolar disorder (BD) and major depressive disorder (MDD). Twenty-six BD patients had a significantly higher prevalence of HG duplication bilaterally compared to 24 age- and sex-matched controls, while their clinical characteristics (e.g., onset age, number of episodes, and medication) did not relate to HG patterns. No significant difference was found for the HG patterns between 56 MDD patients and 33 age- and sex-matched controls, but the patients with a single HG were characterized by more severe depressive/anxiety symptoms compared to those with a duplicated HG. Thus, in keeping with previous findings, the present study suggests that neurodevelopmental pathology associated with gyral formation of the HG during the late gestation period partly overlaps between schizophrenia and BD, but that HG patterns may make a somewhat distinct contribution to the phenomenology of MDD.

Consideration of the adaptive randomization allocation ratio in the presence of treatment group heteroscedasticity in clinical trials

For randomized clinical trials, subjects' variance structures may vary over time among treatment groups, resulting in the heteroscedasticity of residuals in a regression analysis. Commonly used methods that assume equal variance among all treatment groups may not be able to control for a type I error. When the variances are indeed the same across treatment groups, an equal randomization allocation ratio will yield the greatest study power. However, out of ethical concern or urgent need for rare disease clinical trials, more patients may have to be allocated to the study drug arm. In these situations, an unequal randomization ratio should be considered. We propose a group variance-covariance and structures-based method to adapt the randomization ratio after interim analysis. We use simulations to compare commonly used statistical methods for continuous endpoints in assessing the impact of heteroscedasticity in equal and unequal randomization ratios and examine the extent to which the findings are affected by missing data.

Neural substrates of psychosis revealed by altered dependencies between brain activity and white-matter architecture in individuals with 22q11 deletion syndrome

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Function-structural dependency is altered in patients with 22q11 deletion syndrome.

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Stronger dependency in subcortical regions correlates with psychotic symptoms.

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Weaker dependency in cingulate cortex correlates with psychotic symptoms.

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Multimodal and not unimodal indexes were correlated with psychosis emergence.

Background

Dysconnectivity has been consistently proposed as a major key mechanism in psychosis. Indeed, disruptions in large-scale structural and functional brain networks have been associated with psychotic symptoms. However, brain activity is largely constrained by underlying white matter pathways and the study of function-structure dependency, compared to conventional unimodal analysis, allows a biologically relevant assessment of neural mechanisms. The 22q11.2 deletion syndrome (22q11DS) constitutes a remarkable opportunity to study the pathophysiological processes of psychosis.

Methods

58 healthy controls and 57 deletion carriers, aged from 16 to 32 years old, underwent resting-state functional and diffusion-weighted magnetic resonance imaging. Deletion carriers were additionally fully assessed for psychotic symptoms. Firstly, we used a graph signal processing method to combine brain activity and structural connectivity measures to obtain regional structural decoupling indexes (SDIs). We use SDI to assess the differences of functional structural dependency (FSD) across the groups. Subsequently we investigated how alterations in FSDs are associated with the severity of positive psychotic symptoms in participants with 22q11DS.

Results

In line with previous findings, participants in both groups showed a spatial gradient of FSD ranging from sensory-motor regions (stronger FSD) to regions involved in higher-order function (weaker FSD). Compared to controls, in participants with 22q11DS, and further in deletion carriers with more severe positive psychotic symptoms, the functional activity was more strongly dependent on the structure in parahippocampal gyrus and subcortical dopaminergic regions, while it was less dependent within the cingulate cortex. This analysis revealed group differences not otherwise detected when assessing the structural and functional nodal measures separately.

Conclusions

Our findings point toward a disrupted modulation of functional activity on the underlying structure, which was further associated to psychopathology for candidate critical regions in 22q11DS. This study provides the first evidence for the clinical relevance of function-structure dependency and its contribution to the emergence of psychosis.

Disturbance of Ecological Self and Impairment of Affordance Perception

Affordance, a radical concept James Gibson introduced in the 1970s, remains controversial today. Defined as environmental properties taken with reference to an animal's anatomy and action capabilities, affordances are opportunities for action the environment offers. By perceiving affordances, organisms hold meaningful relationships with their surroundings. Affordance is not just a theoretical concept but, as the embodiment of meanings and values, has serious psychological implications. We contend that the lack of these meanings and values underlies the irrational behavior seen in patients with self disorders such as schizophrenia. We reason that it is by perceiving affordances that individuals keep in touch with their surroundings and stay mentally healthy. Using contrapositive reasoning, the reverse could also be true. That is, when individuals experience difficulty maintaining meaningful relations with their surroundings and suffer from mental health problems, we might anticipate that their affordance detection systems are impaired. In two studies conducted in our laboratory, patients with schizophrenia and Alzheimer's disease were shown to have impaired capacity to perceive affordances, a result qualifying as contra-positive evidence corroborating the affordance concept. In addition, our results provide support for accepting contra-positive evidence as a complementary tool to positive evidence for empirically validating concepts such as affordance and meaning.

Pineal morphology of the clinical high-risk state for psychosis and different psychotic disorders

BACKGROUND

Pineal volume reductions have been reported in schizophrenia and clinical high-risk states for the development of psychosis, supporting the role of melatonin dysregulation in the pathophysiology of psychosis. However, it remains unclear whether pineal volume is associated with the later onset of psychosis in individuals at clinical high-risk (CHR) of psychosis or if pineal atrophy is specific to schizophrenia among different psychotic disorders.

METHODS

This magnetic resonance imaging study examined the volume of and cyst prevalence in the pineal gland in 135 individuals at CHR of psychosis [52 (38.5%) subsequently developed psychosis], 162 with first-episode psychosis (FEP), 89 with chronic schizophrenia, and 87 healthy controls. The potential contribution of the pineal morphology to clinical characteristics was also examined in the CHR and FEP groups.

RESULTS

Pineal volumes did not differ significantly between the CHR, FEP, and chronic schizophrenia groups, but were significantly smaller than that in healthy controls. However, pineal volumes were not associated with the later onset of psychosis in the CHR group or FEP sub-diagnosis (i.e., schizophrenia, schizophreniform disorder, affective psychosis, and other psychoses). No significant differences were observed in the prevalence of pineal cysts between the groups, and it also did not correlate with clinical characteristics in the CHR and FEP groups.

CONCLUSION

These results suggest that pineal atrophy is a general vulnerability marker of psychosis, while pineal cysts do not appear to contribute to the pathophysiology of psychosis.

Dopamine-induced pruning in monocyte-derived-neuronal-like cells (MDNCs) from patients with schizophrenia

The long lapse between the presumptive origin of schizophrenia (SCZ) during early development and its diagnosis in late adolescence has hindered the study of crucial neurodevelopmental processes directly in living patients. Dopamine, a neurotransmitter consistently associated with the pathophysiology of SCZ, participates in several aspects of brain development including pruning of neuronal extensions. Excessive pruning is considered the cause of the most consistent finding in SCZ, namely decreased brain volume. It is therefore possible that patients with SCZ carry an increased susceptibility to dopamine's pruning effects and that this susceptibility would be more obvious in the early stages of neuronal development when dopamine pruning effects appear to be more prominent. Obtaining developing neurons from living patients is not feasible. Instead, we used Monocyte-Derived-Neuronal-like Cells (MDNCs) as these cells can be generated in only 20 days and deliver reproducible results. In this study, we expanded the number of individuals in whom we tested the reproducibility of MDNCs. We also deepened the characterization of MDNCs by comparing its neurostructure to that of human developing neurons. Moreover, we studied MDNCs from 12 controls and 13 patients with SCZ. Patients' cells differentiate more efficiently, extend longer secondary neurites and grow more primary neurites. In addition, MDNCs from medicated patients expresses less D1R and prune more primary neurites when exposed to dopamine. Haloperidol did not influence our results but the role of other antipsychotics was not examined and thus, needs to be considered as a confounder.

Feature and decision-level fusion for schizophrenia detection based on resting-state fMRI data

Mental disorders, especially schizophrenia, still pose a great challenge for diagnosis in early stages. Recently, computer-aided diagnosis techniques based on resting-state functional magnetic resonance imaging (Rs-fMRI) have been developed to tackle this challenge. In this work, we investigate different decision-level and feature-level fusion schemes for discriminating between schizophrenic and normal subjects. Four types of fMRI features are investigated, namely the regional homogeneity, voxel-mirrored homotopic connectivity, fractional amplitude of low-frequency fluctuations and amplitude of low-frequency fluctuations. Data denoising and preprocessing were first applied, followed by the feature extraction module. Four different feature selection algorithms were applied, and the best discriminative features were selected using the algorithm of feature selection via concave minimization (FSV). Support vector machine classifiers were trained and tested on the COBRE dataset formed of 70 schizophrenic subjects and 70 healthy subjects. The decision-level fusion method outperformed the single-feature-type approaches and achieved a 97.85% accuracy, a 98.33% sensitivity, a 96.83% specificity. Moreover, feature-fusion scheme resulted in a 98.57% accuracy, a 99.71% sensitivity, a 97.66% specificity, and an area under the ROC curve of 0.9984. In general, decision-level and feature-level fusion schemes boosted the performance of schizophrenia detectors based on fMRI features.

Clinical high risk for psychosis in children and adolescents: A meta-analysis of transition prevalences

The strategic value of early, preventive intervention in psychosis has been a catalytic stepping stone to promoting early intervention in Mental Health. Central to such momentum is the construct of clinical high risk states for psychosis (CHR). While CHR emerge in developmental years, the meta-analytical risk of psychosis among children and adolescents (age 9-18 years) at CHR is still unknown. We conducted a meta-analysis according to PRISMA guidelines including all studies that assessed CHR in children and adolescents (age ≤ 18 years) with validated instruments and provided follow-data on transition to psychosis up to December 31, 2018. We identified 11 eligible studies. Mean age was 15.8 ± 0.8 years, range: 13.8 to 16.8. Transition to psychosis occurred in 93 CHR subjects out of 533 that were enrolled at inception, over a follow-up period ranging from 6 to 72 months. Conversion prevalence was 17.5% (95% CI: 9.9% to 26.5%) in the random-effects model (Q = 30.9; p < .001; I² = 68%), and slightly lower (16.0; 12.9% to 19.5%) in the fixed-effect model. Gender ratio, the criteria used to diagnose the CHR status, and quality of studies had an impact on the estimates of conversion prevalence in the intention-to-treat model without the outlier. Studies of fair quality produced lower estimates of conversion prevalence (11%; 95% CI: 2% to 24%) than those produced by studies of good quality (19%; 95% CI: 11% to 28%). These findings suggest that CHR in adolescence presents commensurable transition prevalences to those found in adult samples, confirming the relevance of CHR criteria for timely risk inception in developmental years. Outcomes other than transition to psychosis (e.g. remission, persistent CHR, socio-functional status or treatment responses) were not systematically reported thereby preventing further, more sophisticated, prognostic stratifications.

Abnormal functional connectivity of the striatum in first-episode drug-naive early-onset Schizophrenia

Abnormal brain network connectivity is strongly implicated in the pathogenesis of schizophrenia. The striatum, consisting of the caudate and putamen, is the major treatment target for antipsychotics, the primary treatments for schizophrenia; however, there are few studies on the functional connectivity (FC) of striatum in drug-naive early-onset schizophrenia (EOS) patients. We examined the FC values of the caudate nucleus and putamen with whole brain by resting-state functional magnetic resonance imaging (RS-fMRI) and the associations with indices of clinical severity. Patients demonstrated abnormal FC between subregions of the putamen and both the visual network (left middle occipital gyrus) and default mode network (bilateral anterior cingulate, left superior frontal, and right middle frontal gyri). Furthermore, FC between dorsorostral putamen and left superior frontal gyrus correlated with both positive symptom subscore and total score on the Positive and Negative Syndrome Scale (PANSS). These findings demonstrate abnormal FC between the striatum and other brain areas even in the early stages of schizophrenia, supporting neurodevelopmental disruption in disease etiology and expression.

The instrumental role of operant paradigms in translational psychiatric research: Insights from a maternal immune activation model of schizophrenia risk

Rigorous behavioral analysis is essential to the translation of research conducted using animal models of neuropsychiatric disease. Here we discuss the use of operant paradigms within our lab as a powerful approach for exploring the biobehavioral bases of disease in the maternal immune activation rat model of schizophrenia. We have investigated a range of disease features in schizophrenia including abnormal perception of time, cognition, learning, motivation, and internal state (psychosis), providing complex insights into brain and behavior. Beyond simple phenotyping, implementing sophisticated operant procedures has been effective in delineating aspects of pathological behavior, identifying interacting pathologies, and isolating contributing mechanisms of disease. We provide comment on the strengths of operant techniques to support high-quality behavioral investigations in fundamental neuropsychiatric research.

Mammalian D-cysteine: A novel regulator of neural progenitor cell proliferation: Endogenous D-cysteine, the stereoisomer with rapid spontaneous in vitro racemization rate, has major neural roles: Endogenous D-cysteine, the stereoisomer with rapid spontaneous in vitro racemization rate, has major neural roles

D-amino acids are being recognized as functionally important molecules in mammals. We recently identified endogenous D-cysteine in mammalian brain. D-cysteine is present in neonatal brain in substantial amounts (mM) and decreases with postnatal development. D-cysteine binds to MARCKS and a host of proteins implicated in cell division and neurodevelopmental disorders. D-cysteine decreases phosphorylation of MARCKS in neural progenitor cells (NPCs) affecting its translocation. D-cysteine controls NPC proliferation by inhibiting AKT signaling. Exogenous D-cysteine inhibits AKT phosphorylation at Thr 308 and Ser 473 in NPCs. D-cysteine treatment of NPCs led to 50% reduction in phosphorylation of Foxo1 at Ser 256 and Foxo3a at Ser 253. We hypothesize that in the developing brain endogenous D-cysteine is as a physiologic regulator of NPC proliferation by inhibiting AKT signaling mediated by Foxo1 and Foxo3a. Endogenous D-cysteine may regulate mammalian neurodevelopment with roles in schizophrenia and Alzheimer's disease (AD).

Styles of Coping with Stress among Healthy People and People with Diagnosis of Schizophrenia and Selected Personality Dimensions

Background: Schizophrenia is considered a chronic and disabling mental disorder that affects approximately one percent of the world’s population. It is characterized by a variable course and its various symptoms may predominate depending on the characteristics of the person. Aim: Recognition of the personality traits and styles of stress-coping applied by healthy people and people diagnosed with schizophrenia. Methods: The study examined 60 people in total: 30 healthy people between 19 and 58 years old and29 people diagnosed with schizophrenia and 1 person with schizophrenia spectrum disorder between 25 and 72 years old. In the present study we used Personality inventory NEO-FFI by Paul Costa and Robert McCreae, designed to diagnose personality traits described in the five-factor model called “The Big Five” and CISS: Coping Inventory for Stressful Situations by N.S. Endler, J.D.A. Parker, designed to diagnose stress-coping styles.

Regulatory variants at 2q33.1 confer schizophrenia risk by modulating distal gene TYW5 expression

Genome-wide association studies have shown that genetic variants at 2q33.1 are strongly associated with schizophrenia. However, potential causal variants in this locus and their roles in schizophrenia remain unknown. Here, we identified two functional variants (rs796364 and rs281759) that disrupt CTCF, RAD21 and FOXP2 binding at 2q33.1. We systematically investigated the regulatory mechanisms of these two variants with serial experiments, including reporter gene assays and electrophoretic mobility shift assay. Intriguingly, these two single nucleotide polymorphisms physically interacted with TYW5 and showed the most significant associations with TYW5 expression in human brain. Consistently, CRISPR-Cas9-mediated genome editing confirmed the regulatory effect of the two single nucleotide polymorphisms on TYW5 expression. Additionally, expression analysis indicated that TYW5 was significantly upregulated in brains of schizophrenia cases compared with controls, suggesting that rs796364 and rs281759 might confer schizophrenia risk by modulating TYW5 expression. We over-expressed TYW5 in mouse neural stem cells and rat primary neurons to mimic its upregulation in schizophrenia and found significant alterations in the proliferation and differentiation of neural stem cells, as well as dendritic spine density following TYW5 overexpression, indicating its important roles in neurodevelopment and spine morphogenesis. Furthermore, we independently confirmed the association between rs796364 and schizophrenia in a Chinese cohort of 8202 subjects. Finally, transcriptome analysis revealed that TYW5 affected schizophrenia-associated pathways. These lines of evidence consistently revealed that rs796364 and rs281759 might contribute to schizophrenia risk by regulating the expression of TYW5, a gene whose expression dysregulation affects two important schizophrenia pathophysiological processes (i.e. neurodevelopment and dendritic spine formation).

Effect of Co-Treatment of Olanzapine with SEP-363856 in Mice Models of Schizophrenia

Olanzapine is a commonly used drug in the treatment of schizophrenia, but its clinical application has been restricted by metabolic-related side effects. In order to mitigate the weight gain side effects caused by olanzapine, other drugs with different targets were selected for combined use and evaluated in animal models of schizophrenia. SEP-363856 is a novel psychotropic agent which is under phase III clinical trials for schizophrenia treatment. The aim of the research was to evaluate whether co-administration of olanzapine and SEP-363856 exerts synergistic anti-schizophrenic effects in the apomorphine (APO)-induced climbing test, the MK-801-induced hyperactivity test, and the Morris water maze test, and therefore reduces the weight gain side effects induced by olanzapine. Through isobolographic analysis, the results showed a synergistic interaction in the climbing test; the experimental ED30 (3 mg/kg) was significantly smaller (p < 0.05) than the theoretical ED30 (5 mg/kg). Additionally, such potentiating effects appeared additive in the MK-801 challenge experiment. Co-treatment with an effective dose of olanzapine and a low dose of SEP-363856 reversed MK-801-induced cognitive impairment symptoms in mice. Moreover, combination treatment with olanzapine and SEP-363856 controls sustained weight gain in mice with chronic exposure to olanzapine. These results support further clinical trials to test the effectiveness of co-treatment of olanzapine and SEP-363856 for controlling symptoms and weight gain in patients with schizophrenia during antipsychotic treatments.

Study of the acute and repeated dose 28-day oral toxicity in mice treated with PT-31, a molecule with potential antipsychotic profile

Schizophrenia is a psychiatric disorder that affects 1% of the world population and is treated with antipsychotics, which may induce important biochemical and hematological alterations. Since it is necessary to verify the safety of new molecules with antipsychotic potential, the present study aimed to evaluate the oral toxicity of PT-31, a putative α₂-adrenoreceptor agonist, after acute (2000 mg/kg) and repeated doses (28 days) gavage treatment, in three different doses: minimum effective dose in animal models (10 mg/kg), twice the dose (20 mg/kg), and four times the dose (40 mg/kg), as recommended by the OECD guidelines. Balb/C female adult mice were used, and biochemical, hematological, and histopathological analyses were performed. PT-31 10 and 20 mg/kg did not cause biochemical alterations related to hepatic and renal toxicity, and neither altered glycemic and lipid profiles. The preclinical dose of PT-31 also did not promote mice histopathological changes in the liver, kidney, and brain. In the hematimetric parameters, PT-31 only increased HGB at 20 mg/kg, and MCH and MCHC at 40 mg/kg. However, all the tested doses of PT-31 showed platelet increase, which must be better investigated. Therefore, further studies are needed to investigate the safety of PT-31 as a potential antipsychotic drug.

Complicated Grief, Depression, Health and Attachment Style in First Degree Relatives of Individuals with a Chronic Psychotic Disorders

Complicated grief (CG) is a form of unrelenting grief after the death of a loved one. However, family members of individuals who suffer from Schizophrenia, Schizoaffective disorders and Bipolar disorder may experience symptoms of CG even though their loved one is still alive. The present study assessed CG and risk factors for CG in first degree relatives of individuals with severe chronic mental illness. The incidence of CG was examined in 78 parents, siblings, adult children and spouses recruited through organizations and social media that provide support services for individuals suffering from mental illness and their families. High rates of CG (39.7%) were found in this group. CG was associated with a higher prevalence of posttraumatic and depression symptoms and poorer physical health. These findings may contribute to heightening therapists' awareness of the importance of assessing, acknowledging and resolving CG in the family members of patients with chronic psychotic disorders.

Altered temporal variability in brain functional connectivity identified by fuzzy entropy underlines schizophrenia deficits

Investigation of the temporal variability of resting-state brain networks informs our understanding of how neural connectivity aggregates and disassociates over time, further shedding light on the aberrant neural interactions that underlie symptomatology and psychosis development. In the current work, an electroencephalogram-based sliding window analysis was utilized for the first time to measure the nonlinear complexity of dynamic resting-state brain networks of schizophrenia (SZ) patients by applying fuzzy entropy. The results of this study demonstrated the attenuated temporal variability among multiple electrodes that were distributed in the frontal and right parietal lobes for SZ patients when compared with healthy controls (HCs). Meanwhile, a concomitant strengthening of the posterior and peripheral flexible connections that may be attributed to the excessive alertness or sensitivity of SZ patients to the external environment was also revealed. These temporal fluctuation distortions combined reflect an abnormality in the coordination of functional network switching in SZ, which is further the source of worse task performance (i.e., P300 amplitude) and the negative relationship between individual complexity metrics and P300 amplitude. Notably, when using the network metrics as features, multiple linear regressions of P300 amplitudes were also exactly achieved for both the SZ and HC groups. These findings shed light on the pathophysiological mechanisms of SZ from a temporal variability perspective and provide potential biomarkers for quantifying SZ's progressive neurophysiological deterioration.

Cannabidiol for at risk for psychosis youth: A randomized controlled trial

BACKGROUND

No biological treatment has been firmly established for the at-risk stage of psychotic disorder. In this study we aim to test if subthreshold psychotic symptoms can be effectively treated with cannabidiol (CBD), a non-psychoactive compound of the plant Cannabis sativa. The question has taken on increased importance in the wake of evidence questioning both the need and efficacy of specific pharmacological interventions in the ultra-high risk (UHR) for psychosis group.

METHODS

Three-arm randomized controlled trial of 405 patients (135 per arm) aged 12-25 years who meet UHR for psychosis criteria. The study includes a 6-week lead-in phase during which 10% of UHR individuals are expected to experience symptom remission. Participants will receive CBD (per oral) at doses 600 or 1000 mg per day (fixed schedule) for 12 weeks. Participants in the third arm of the trial will receive matching placebo capsules. Primary outcome is severity of positive psychotic symptoms as measured by the Comprehensive Assessment of At-Risk Mental States at 12 weeks. We hypothesize that CBD will be significantly more effective than placebo in improving positive psychotic symptoms in UHR patients. All participants will also be followed up 6 months post baseline to evaluate if treatment effects are sustained.

CONCLUSION

This paper reports on the rationale and protocol of the Cannabidiol for At Risk for psychosis Youth (CanARY) study. This study will test CBD for the first time in the UHR phase of psychotic disorder.

Identification and predictive analysis for participants at ultra-high risk of psychosis: A comparison of three psychometric diagnostic interviews

BACKGROUND

An accurate identification of individuals at ultra-high risk (UHR) based on psychometric tools to prospectively identify psychosis as early as possible is required for indicated preventive intervention. The diagnostic comparability of several psychometric tools, including the comprehensive assessment of at risk mental state (CAARMS), the structured interview for psychosis-risk syndrome (SIPS) and the bonn scale for the assessment of basic symptoms (BSABS), is unknown.

AIM

To address the psychometric comparability of CAARMS, SIPS and BSABS for subjects who are close relatives of patients with schizophrenia.

METHODS

In total, 189 participants aged 18-58 years who were lineal relative by blood and collateral relatives by blood up to the third degree of kinship of patients with schizophrenia were interviewed in the period of May 2017 to January 2019. Relatives of the participants diagnosed schizophrenia were excluded. All the participants were assessed for a UHR state by three psychometric tools (CAARMS, SIPS and BSABS). The psychometric diagnosis results included at risk of psychosis (UHR+), not at risk of psychosis (UHR-) and psychosis. Demographic and clinical characteristics were also measured. The inter-rater agreement was assessed for evaluation of the coherence of the three scales. Transition rates for UHR+ subjects to psychosis within 2 years were also recorded.

RESULTS

The overall agreement percentages were 93.12%, 92.06% and 93.65% of CAARMS and SIPS, SIPS and BSABS and CAARMS and BSABS, respectively. The overall agreement percentage of the relative functional impairment of the three groups (UHR+, not at risk of psychosis and psychosis) were 89.24%, 86.36% and 88.12%, respectively. The inter-rater reliability of the CAARMS, SIPS and BSABS total score was 0.90, 0.89 and 0.85. The inter-rater reliability was very good to excellent for all the subscales of these three instruments. For CAARMS, SIPS and BSABS, the kappa coefficient about UHR criteria agreement was 0.87, 0.84 and 0.82, respectively (P < 0.001). The transition rates of UHR+ to psychosis within 2 years were 16.7% (CAARMS), 10.0% (SIPS) and 17.7% (BSABS).

CONCLUSION

There is good diagnostic agreement between the CAARMS, SIPS and BSABS towards identification of UHR participants who are close relatives of patients with schizophrenia.

Histone Acetylation and Methylation Underlie Oligodendroglial and Myelin Susceptibility in Schizophrenia

Schizophrenia is a complex neuropsychiatric disorder affected by both genetic and epigenetic factors. Except for neuronal dysfunction, oligodendroglial abnormalities also contribute to the disease pathogenesis, characterized by a robust dysregulation of oligodendrocyte and myelin related genes. Accumulating evidence shows that histone modifications play important roles in transcriptional regulation of the genes crucial for oligodendrocyte differentiation and myelination. Specifically, the histone acetylation and methylation were two well-recognized histone modification abnormalities in the schizophrenic brains. In this mini-review, we will describe the dynamic changes of histone acetylation and methylation in schizophrenia, which may coordinate and induce deleterious epigenetic memory in oligodendroglial cells, and further lead to oligodendrocyte and myelin deficits. Precise modulation of histone modification status in oligodendroglial cells needs to secure the balance of epigenetic marks, which may revise the therapeutic strategy for the white matter etiology of neuropsychiatric disorders.

Childhood trauma exposure and personality traits in schizophrenia patients

Childhood trauma in schizophrenia (SCZ) is associated with aberrant neurobiological downstream effects and cognitive deficits that markedly hinder patient outcome and functioning. However, the relationship between specific forms of childhood abuse and the tendency for certain personality traits in patients with SCZ has not been comprehensively studied yet. We recruited 374 SCZ patients and screened for history of physical abuse (PA), emotional abuse (EA), sexual abuse (SA), physical neglect (PN) and emotional neglect (EN) using the Childhood Trauma Questionnaire and measured personality traits using the NEO Five-Factor inventory. Using CTQ cut-off scores, the prevalence of EA, PA, SA, EN and PN was 60.7%, 42.0%, 37.7%, 64.2% and 54.3% respectively. Exposure to any form of childhood abuse was associated with increased neuroticism. Exposure to EA, SA, PN and EN was correlated with decreased agreeableness and conscientiousness scores. PN, EN and PA exposure was associated with decreased openness while EA, PN and EN exposure was associated with decreased extraversion. Furthermore, a positive correlation was found between all forms of childhood abuse and trait neuroticism whereas negative correlations were found between certain forms of childhood abuse and all other personality traits. Exposure to specific forms of childhood abuse was associated with specific personality traits in patients with SCZ.

The enduring behavioral and neurobiological effects of a flavor cue paired with alcohol drinking during adolescence on the incentive properties of the flavor cue in adulthood in female alcohol-preferring (P) rats

BACKGROUND

Alcohol use disorders (AUDs) affect 15 million people nationwide, 4% of which are adolescents (ages 12-17) and adolescents who binge drink significantly increase their likelihood of suffering from an AUD in adulthood. Research shows that cues (i.e. flavors) paired with alcohol (EtOH) produce significant cue-induced alcohol craving and contribute to relapse in adolescent and adult populations. However, there is a lack of research focused on how cues that accompany EtOH drinking during adolescence, affect EtOH craving later in life. The current study sought to examine the sex- and developmental-dependent effects of adolescent exposure to flavor cues associated with EtOH on operant-lick behavior and cue-induced dopamine (DA) levels within the nucleus accumbens shell (AcbSh; reward structure) in adulthood.

METHODS

Adolescent alcohol-preferring (P) rats were randomly assigned to one of 4 groups and received 24 hr. access to three bottles on their home cage: Paired: 0.1% blueberry flavor extract (BB) + 15% v/v EtOH and 2 water bottles; Unpaired: 0.1% BB, 15% v/v EtOH, and water; 15% EtOH alone, and 2 water bottles; BB alone and 2 water bottles. Home cage fluid consumption was measured for 2-weeks. On the third week bottles were removed and all animals underwent 9 days of operant training using an operant sipper paradigm. This consisted of two sipper spouts connected to the computer by a lickometer, which registered tongue contacts with the sipper tube (Paired: BB+EtOH or water; Unpaired BB or EtOH; EtOH alone: EtOH or water; BB alone: BB or water). When the fixed ratio (FR) requirement for number of licks/tongue contacts was met, a liquid delivery solenoid dispensed 0.05 ml of fluid into the sipper tube. Following the final operant session all rats remained in their home-cage for approximately 40 days until adulthood at which point they were returned to the operant chambers and tested for appetitive and consummatory behavior in response to the flavor cue (all rats: BB or water; NO EtOH). Two weeks after the final operant session all rats underwent microdialysis testing to examine cue-induced DA levels in the AcbSh.

RESULTS

Data indicated that animals in the paired group exhibited a significantly greater level of licking at the BB sipper and a significantly greater level of DA release in response to the flavor cue compared to the other groups.

CONCLUSIONS

Overall, the data suggest that cues paired with EtOH during adolescence may produce persistent changes to the behavioral and neurobiological mechanisms that contribute to an increased risk of developing an AUD later in life.

Autism spectrum disorder and schizophrenia: An updated conceptual review

Autism spectrum disorder (ASD) and schizophrenia (SCZ) are separate disorders, with distinct clinical profiles and natural histories. ASD, typically diagnosed in childhood, is characterized by restricted or repetitive interests or behaviors and impaired social communication, and it tends to have a stable course. SCZ, typically diagnosed in adolescence or adulthood, is characterized by hallucinations and delusions, and tends to be associated with declining function. However, youth with ASD are three to six times more likely to develop SCZ than their neurotypical counterparts, and increasingly, research has shown that ASD and SCZ converge at several levels. We conducted a systematic review of studies since 2013 relevant to understanding this convergence, and present here a narrative synthesis of key findings, which we have organized into four broad categories: symptoms and behavior, perception and cognition, biomarkers, and genetic and environmental risk. We then discuss opportunities for future research into the phenomenology and neurobiology of overlap between ASD and SCZ. Understanding this overlap will allow for researchers, and eventually clinicians, to understand the factors that may make a child with ASD vulnerable to developing SCZ. LAY SUMMARY: Autism spectrum disorder and schizophrenia are distinct diagnoses, but people with autism and people with schizophrena share several characteristics. We review recent studies that have examined these areas of overlap, and discuss the kinds of studies we will need to better understand how these disorders are related. Understanding this will be important to help us identify which autistic children are at risk of developing schizophrenia.

LY395756 promotes NR2B expression via activation of AKT/CREB signaling in the juvenile methylazoxymethanol mice model of schizophrenia

INTRODUCTION

Synaptic N-methyl-d-aspartate receptor subtype 2B(NR2B) is significantly reduced in prefrontal cortex (PFC) in the neurodevelopmental methylazoxymethanol (MAM) model of schizophrenia (SCZ). Recent research has shown that LY395756 can effectively restore NR2B levels and improve cognitive performance in juvenile MAM mice model. However, the underlying mechanisms of these beneficial effects remain unclear.

MATERIALS AND METHODS

Juvenile MAM mice model of SCZ is used in our study. Synaptic membrane protein levels were examined by western blotting under different treatment conditions. Interaction of cAMP-response element binding protein (CREB) and the promoter of NR2B was detected by the chromatin immunoprecipitation (ChIP) assay. Further examination of signaling pathway that mediates NR2B expression was also investigated by western blotting.

RESULTS

In the PFC of the juvenile MAM mice schizophrenia model, CREB was found to directly bind with the promoter of NR2B. LY395756 activated the phosphorylation of AKT. Phosphorylated AKT subsequently induced the phosphorylation of CREB, and the activated CREB promoted the expression of NR2B. Subsequent experiments showed that the dephosphorylation of CREB induced by protein phosphatase 1 (PP1) can inhibit NR2B levels. Taken together, these findings support that the AKT/CREB signaling pathway is essential for the promoting effect of LY395756 on synaptic NR2B in PFC in juvenile MAM mice SCZ model.

CONCLUSIONS

Our investigation has identified a novel mechanism by which LY395756 increases NR2B expression in juvenile MAM mice SCZ model. The AKT/CREB signaling pathway warrants further research as a potential direction for clinical treatment of SCZ.

Premorbid adjustment in childhood is associated with later emotion management in first-episode schizophrenia

Poor premorbid adjustment and social functioning deficits are recognized as cardinal features of schizophrenia. Whether premorbid maladjustment is associated with interpersonal functioning problems that manifest during the first episode of psychosis is less well-established. No previous work has investigated the relationship between premorbid adjustment and a key component of social cognition (emotion management) during the early phase of schizophrenia. A sample of 119 individuals (40 experiencing a first episode of schizophrenia, FE-SZ, 22 experiencing a first episode of another psychotic disorder, FE-OP, and 57 healthy controls, HC) participated in an assessment of premorbid adjustment and emotion management, measured using the Cannon-Spoor Premorbid Adjustment Scale (PAS) and the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT) Managing Emotions (ME) scale. The relationship between premorbid adjustment (from age 5 to onset of psychotic symptoms) and ME was examined, as well as the specific relationship between childhood premorbid adjustment (ages 5-11) and ME. Results indicated that both FE-SZ and FE-OP participants exhibited significantly worse premorbid adjustment (all p's < 0.01) across development and lower ME scores when compared to HC participants. Among FE-SZ participants only, premorbid maladjustment in childhood was correlated with deficits in emotion management. This study is the first to suggest that poor premorbid social and academic functioning in childhood is related to later deficits in emotion management in those experiencing a first episode of schizophrenia. These results point to a possible relationship between early developmental deficits in premorbid social and school functioning and social cognitive deficits during the early (first episode) phase of schizophrenia.

Mapping normative trajectories of cognitive function and its relation to psychopathology symptoms and genetic risk in youth

Background

Adolescence hosts a sharp increase in the incidence of mental disorders. The prodromal phases are often characterized by cognitive deficits that predate disease onset by several years. Characterization of cognitive performance in relation to normative trajectories may have value for early risk assessment and monitoring.

Methods

Youth aged 8 to 21 years (N = 6481) from the Philadelphia Neurodevelopmental Cohort were included. Performance scores from a computerized neurocognitive battery were decomposed using principal component analysis, yielding a general cognitive score. Items reflecting various aspects of psychopathology from self-report questionnaires and collateral caregiver information were decomposed using independent component analysis, providing individual domain scores. Using normative modeling and Bayesian statistics, we estimated normative trajectories of cognitive function and tested for associations between cognitive deviance and psychopathological domain scores. In addition, we tested for associations with polygenic scores for mental and behavioral disorders often involving cognition, including schizophrenia, bipolar disorder, attention-deficit/hyperactivity disorder, and Alzheimer's disease.

Results

More negative normative cognitive deviations were associated with higher general psychopathology burden and domains reflecting positive and prodromal psychosis, attention problems, norm-violating behavior, and anxiety. In addition, better performance was associated with higher joint burden of depression, suicidal ideation, and negative psychosis symptoms. The analyses revealed no evidence for associations with polygenic scores.

Conclusions

Our results show that cognitive performance is associated with general and specific domains of psychopathology in youth. These findings support the close links between cognition and psychopathology in youth and highlight the potential of normative modeling for early risk assessment.

Auditory acuity and musical ability in young adults with high schizotypal traits

BACKGROUND

Despite auditory cognition dysfunction being consistently found in people with schizophrenia, the evidence from non-clinical individuals with schizotypy is rare and inconsistent. No studies thus far have comprehensively assessed the association among auditory perception, musical cognition, and schizotypy in non-clinical samples.

AIM

We aimed to explore abnormalities in auditory skills, from basic perception to musical ability, among individuals with schizotypal traits.

METHOD

An extreme-group design was adopted. Sixty-six participants from the schizotypy and control groups were screened from 1093 young adults using the Schizotypal Personality Questionnaire (SPQ). Auditory acuity was assessed using four auditory discrimination threshold tests, and musical ability was evaluated through the Montreal Battery of Evaluation of Amusia (MBEA). Basic demographic information and musical backgrounds were assessed and matched, and depression, anxiety, and digit-span index were evaluated and controlled.

RESULTS

Elevated sensitivity in auditory perception and improved musical talent were found in young adults with high schizotypal traits. Auditory acuity and musical ability were positively correlated with schizotypy and its factors among participants across groups. A regression analysis in the control group showed that cognitive perceptual scores of SPQ positively predicted auditory temporal sensitivity. The mediation analysis revealed an indirect effect of pure tone duration discrimination between musical rhythmic ability and positive factor of schizotypy.

DISCUSSION

Elevated sensitivity in auditory temporal perception and improved musical talent in young adults with high schizotypy may contribute to explaining the variation of auditory process in the development of schizophrenia-spectrum disorders. It can also help elucidate the association between psychopathology and creativity in auditory modality.

Anandamide Hydrolysis Inhibition Reverses the Long-Term Behavioral and Gene Expression Alterations Induced by MK-801 in Male Rats: Differential CB1 and CB2 Receptor-Mediated Effects

NMDA receptor blockade in rodents is commonly used to induce schizophrenia-like behavioral abnormalities, including cognitive deficits and social dysfunction. Aberrant glutamate and GABA transmission, particularly in adolescence, is implicated in these behavioral abnormalities. The endocannabinoid system modulates glutamate and GABA transmission, but the impact of endocannabinoid modulation on cognitive and social dysfunction is unclear. Here, we asked whether late-adolescence administration of the anandamide hydrolysis inhibitor URB597 can reverse behavioral deficits induced by early-adolescence administration of the NMDA receptor blocker MK-801. In parallel, we assessed the impact of MK-801 and URB597 on mRNA expression of glutamate and GABA markers. We found that URB597 prevented MK-801-induced novel object recognition deficits and social interaction abnormalities in adult rats, and reversed glutamate and GABA aberrations in the prelimbic PFC. URB597-mediated reversal of MK-801-induced social interaction deficits was mediated by the CB1 receptor, whereas the reversal of cognitive deficits was mediated by the CB2 receptor. This was paralleled by the reversal of CB1 and CB2 receptor expression abnormalities in the basolateral amygdala and prelimbic PFC, respectively. Together, our findings show that interfering with NMDA receptor function in early adolescence has a lasting impact on phenotypes resembling the negative symptoms and cognitive deficits of schizophrenia and on glutamate and GABA marker expression in the PFC. Prevention of behavioral and molecular abnormalities by late-adolescence URB597 via CB1 and CB2 receptors suggests that endocannabinoid stimulation may have therapeutic potential in addressing treatment-resistant symptoms.