Dorsal striatal volumes in never-treated patients with first-episode schizophrenia before and during acute treatment

Prenatal stress alters mouse offspring dorsal striatal development and placental function in sex-specific ways

Prenatal stress is a risk factor for neurodevelopmental disorders (NDDs), including autism spectrum disorder (ASD). However, how early stress modification of brain development contributes to this pathophysiology is poorly understood. Ventral forebrain regions such as dorsal striatum are of particular interest: dorsal striatum modulates movement and cognition, is altered in NDDs, and has a primarily GABAergic population. Here, we examine effects of prenatal stress on adult movement, cognition, and dorsal striatum neurobiology in mice using striatal-dependent behavioral assays, immunohistochemistry, embryonic ventral forebrain transcriptomics, and placental transcriptomics. We found prenatal stress affected adult procedural, habit, and reversal learning in sex-specific ways. Stress also increased adult dorsal striatal GABAergic neurons - an effect largely driven by males. We sought to examine the developmental origins of these adult brain changes. We found similar sex-specific dorsal striatal cellular changes in earlier points of development. The dorsal striatum primordium--embryonic ventral forebrain-showed that prenatal stress increased DNA replication and cell cycle pathways in male but not female transcriptomics and cellular biology. Unique signatures may have arisen from male-female placental differences. Stress-induced placental transcriptomics showed upregulated morphogenesis pathways in males while females downregulated morphogenic, hormonal, and cellular response pathways. Our findings suggest that prenatal stress could affect placenta function and also alter the GABAergic population of dorsal striatum differentially between the sexes.

Alterations in the volume and shape of the basal ganglia and thalamus in schizophrenia with auditory hallucinations

Different lines of evidence indicate that the structure and physiology of the basal ganglia and the thalamus is disturbed in schizophrenia. However, it is unknown whether the volume and shape of these subcortical structures are affected in schizophrenia with auditory hallucinations (AH), a core positive symptom of the disorder. We took structural MRI from 63 patients with schizophrenia, including 36 patients with AH and 27 patients who had never experienced AH (NAH), and 51 matched healthy controls. We extracted volumes for the left and right thalamus, globus pallidus, putamen, caudate and nucleus accumbens. Shape analysis was also carried out. When comparing to controls, the volume of the right globus pallidus, thalamus, and putamen, was only affected in AH patients. The volume of the left putamen was also increased in individuals with AH, whereas the left globus pallidus was affected in both groups of patients. The shapes of right and left putamen and thalamus were also affected in both groups. The shape of the left globus pallidus was only altered in patients lacking AH, both in comparison to controls and to cases with AH. Lastly, the general PANSS subscale was correlated with the volume of the right thalamus, and the right and left putamen, in patients with AH. We have found volume and shape alterations of many basal ganglia and thalamus in patients with and without AH, suggesting in some cases a possible relationship between this positive symptom and these morphometric alterations.

Intracranial and subcortical volumes in adolescents with early-onset psychosis: A multisite mega-analysis from the ENIGMA consortium

Early-onset psychosis disorders are serious mental disorders arising before the age of 18 years. Here, we investigate the largest neuroimaging dataset, to date, of patients with early-onset psychosis and healthy controls for differences in intracranial and subcortical brain volumes. The sample included 263 patients with early-onset psychosis (mean age: 16.4 ± 1.4 years, mean illness duration: 1.5 ± 1.4 years, 39.2% female) and 359 healthy controls (mean age: 15.9 ± 1.7 years, 45.4% female) with magnetic resonance imaging data, pooled from 11 clinical cohorts. Patients were diagnosed with early-onset schizophrenia (n = 183), affective psychosis (n = 39), or other psychotic disorders (n = 41). We used linear mixed-effects models to investigate differences in intracranial and subcortical volumes across the patient sample, diagnostic subgroup and antipsychotic medication, relative to controls. We observed significantly lower intracranial (Cohen's d = -0.39) and hippocampal (d = -0.25) volumes, and higher caudate (d = 0.25) and pallidum (d = 0.24) volumes in patients relative to controls. Intracranial volume was lower in both early-onset schizophrenia (d = -0.34) and affective psychosis (d = -0.42), and early-onset schizophrenia showed lower hippocampal (d = -0.24) and higher pallidum (d = 0.29) volumes. Patients who were currently treated with antipsychotic medication (n = 193) had significantly lower intracranial volume (d = -0.42). The findings demonstrate a similar pattern of brain alterations in early-onset psychosis as previously reported in adult psychosis, but with notably low intracranial volume. The low intracranial volume suggests disrupted neurodevelopment in adolescent early-onset psychosis.

Trappc9 deficiency in mice impairs learning and memory by causing imbalance of dopamine D1 and D2 neurons

Genetic mutations in the gene encoding transport protein particle complex 9 (trappc9), a subunit of TRAPP that acts as a guanine nucleotide exchange factor for rab proteins, cause intellectual disability with brain structural malformations by elusive mechanisms. Here, we report that trappc9-deficient mice exhibit a broad range of behavioral deficits and postnatal delay in growth of the brain. Contrary to volume decline of various brain structures, the striatum of trappc9 null mice was enlarged. An imbalance existed between dopamine D1 and D2 receptor containing neurons in the brain of trappc9-deficient mice; pharmacological manipulation of dopamine receptors improved performances of trappc9 null mice to levels of wild-type mice on cognitive tasks. Loss of trappc9 compromised the activation of rab11 in the brain and resulted in retardation of endocytic receptor recycling in neurons. Our study elicits a pathogenic mechanism and a potential treatment for trappc9-linked disorders including intellectual disability.

What a Clinician Should Know About the Neurobiology of Schizophrenia: A Historical Perspective to Current Understanding

The brain is no doubt the "organ" of psychiatry; yet, over the years, few evidence-based classifications of psychiatric disorders have been based on brain mechanisms. The National Institute of Mental Health notably proposed one such system, known as Research Domain Criteria, although it has not yet influenced any changes in the DSM. Of all the major psychiatric disorders, the brain has been studied most extensively in schizophrenia, with its speculative pathology first documented by Emil Kraepelin as early as the beginning of the 20th century. Subsequently, the revolution in technology over the past 50 years has changed how investigators are able to view the brain before death without performing biopsies. Schizophrenia is thus found to have both structural and functional widespread brain anomalies that likely lead to its clinical deterioration. At the onset of illness, acquiring an MRI scan could be part of the routine evaluation to determine how progressive the disease has so far been. However, this practice is not yet recognized by the American Psychiatric Association in any of its guidelines on the treatment of schizophrenia.

Subcortical Brain Volume Abnormalities in Individuals With an At-risk Mental State

Previous structural magnetic resonance imaging studies of psychotic disorders have demonstrated volumetric alterations in subcortical (ie, the basal ganglia, thalamus) and temporolimbic structures, which are involved in high-order cognition and emotional regulation. However, it remains unclear whether individuals at high risk for psychotic disorders with minimal confounding effects of medication exhibit volumetric changes in these regions. This multicenter magnetic resonance imaging study assessed regional volumes of the thalamus, caudate, putamen, nucleus accumbens, globus pallidus, hippocampus, and amygdala, as well as lateral ventricular volume using FreeSurfer software in 107 individuals with an at-risk mental state (ARMS) (of whom 21 [19.6%] later developed psychosis during clinical follow-up [mean = 4.9 years, SD = 2.6 years]) and 104 age- and gender-matched healthy controls recruited at 4 different sites. ARMS individuals as a whole demonstrated significantly larger volumes for the left caudate and bilateral lateral ventricles as well as a smaller volume for the right accumbens compared with controls. In male subjects only, the left globus pallidus was significantly larger in ARMS individuals. The ARMS group was also characterized by left-greater-than-right asymmetries of the lateral ventricle and caudate nucleus. There was no significant difference in the regional volumes between ARMS groups with and without later psychosis onset. The present study suggested that significant volume expansion of the lateral ventricle, caudate, and globus pallidus, as well as volume reduction of the accumbens, in ARMS subjects, which could not be explained only by medication effects, might be related to general vulnerability to psychopathology.

Advancing study of cognitive impairments for antipsychotic-naïve psychosis comparing high-income versus low- and middle-income countries with a focus on urban China: Systematic review of cognition and study methodology

BACKGROUND

Comparing the course of antipsychotic-naïve psychosis in low- and middle-income countries (LMIC) may help to illuminate core pathophysiologies associated with this condition. Previous reviews-primarily from high-income countries (HIC)-identified cognitive deficits in antipsychotic-naïve, first-episode psychosis, but did not examine whether individuals with psychosis with longer duration of untreated psychosis (DUP > 5 years) were included, nor whether LMIC were broadly represented.

METHOD

A comprehensive search of PUBMED from January 2002-August 2018 identified 36 studies that compared cognitive functioning in antipsychotic-naïve individuals with psychosis (IWP) and healthy controls, 20 from HIC and 16 from LMIC.

RESULTS

A key gap was identified in that LMIC study samples were primarily shorter DUP (<5 years) and were primarily conducted in urban China. Most studies matched cases and controls for age and gender but only 9 (24%) had sufficient statistical power for cognitive comparisons. Compared with healthy controls, performance of antipsychotic-naïve IWP was significantly worse in 81.3% (230/283) of different tests of cognitive domains assessed (90.1% in LMIC [118/131] and 73.7% [112/152] in HIC).

CONCLUSIONS

Most LMIC studies of cognition in antipsychotic-naïve IWP adopted standardized procedures and, like HIC studies, found broad-based impairments in cognitive functioning. However, these LMIC studies were often underpowered and primarily included samples typical of HIC: primarily male, young-adult, high-school educated IWP, in their first episode of illness with relatively short DUP (<5 years). To enhance understanding of the long-term natural course of cognitive impairments in untreated psychosis, future studies from LMIC should recruit community-dwelling IWP from rural areas where DUP may be longer.

Antipsychotic Medication in Sub-Saharan Africa: A Systematic Literature Review

PURPOSE

There is limited evidence on the use of antipsychotic medications to treat people with schizophrenia in Sub-Saharan Africa (SSA). This systematic literature review identified original research on use of antipsychotic drugs for primary psychotic disorders in SSA, assessed the methodological quality of studies, summarized intervention strategies, and examined patient-level outcomes.

METHODS

PubMed, PsychInfo, Cochrane Collaboration, African Journals Online, and CINAHL databases were searched for studies in SSA that focused on antipsychotic treatment for primary psychotic disorders and that investigated at least one patient-level outcome. Articles in English and published before April 2019 were included. Epidemiological studies, drug discontinuation studies, studies with drugs other than antipsychotics, and multicenter studies that did not specify SSA results were excluded. An adapted standardized instrument assessed methodological quality.

RESULTS

Twenty-six articles were reviewed. Three levels of evidence were found: single-group reports, quasi-experimental studies, and randomized controlled trials. Study outcomes included change in psychiatric symptoms, adverse effects, remission rates, or change in functional status. Nine studies reported improvements in psychiatric symptoms with antipsychotic medication. Seven studies investigating adverse effects of antipsychotics found that they were associated with an increase in metabolic syndrome. Two studies reported that remission was achieved in most subjects, and one study reported improvements in functional status.

CONCLUSIONS

Despite adverse effects, treatment with antipsychotic medications may be beneficial for individuals with primary psychotic disorders in SSA. Apart from South Africa, there is a scarcity of research on antipsychotics from countries in SSA, and there are numerous important gaps in the literature.

Reduced density of oligodendrocytes and oligodendrocyte clusters in the caudate nucleus in major psychiatric illnesses

Functional dysconnectivity in schizophrenia and affective disorders may be associated with myelin and oligodendrocyte abnormalities. Altered network integration involving the caudate nucleus (CN) and metabolic abnormalities in fronto-striatal-thalamic white matter tracts have been reported in schizophrenia and impaired patterns of cortico-caudate functional connectivity have been found in both bipolar disorder (BPD) and schizophrenia compared to healthy controls. Postmortem studies have found ultrastructural dystrophy and degeneration of oligodendrocytes and dysmyelination in the CN in schizophrenia and BPD. We aimed to test the hypothesis that oligodendrocyte density may be reduced in the CN in major psychiatric disorders and may thereby form the cellular basis for the functional dysconnectivity observed in these disorders. Optical disector was used to estimate the numerical density (Nv) of oligodendrocytes and oligodendrocyte clusters (OLC) in the CN of cases with schizophrenia, BPD and major depressive disorder (MDD) and in normal controls (15 cases per group). A significant reduction in the Nv of oligodendrocytes was found in schizophrenia and BPD as compared to the control group (p < 0.05), and the Nv of OLC was significantly lowered in schizophrenia and BPD compared to controls (p < 0.05). There were no significant differences between MDD and control groups. The Nv of OLC was significantly decreased in the left hemisphere in schizophrenia as compared to the left hemisphere of the control group (-52%, p < 0.01). The data indicates that a decreased density of oligodendrocytes and OLC could contribute to the altered functional connectivity of the CN in subjects with severe mental illnesses.

Depressive psychopathology in first-episode schizophrenia spectrum disorders: a systematic review, meta-analysis and meta-regression

BACKGROUND

Despite knowing for many decades that depressive psychopathology is common in first-episode schizophrenia spectrum disorders (FES), there is limited knowledge regarding the extent and nature of such psychopathology (degree of comorbidity, caseness, severity) and its demographic, clinical, functional and treatment correlates. This study aimed to determine the pooled prevalence of depressive disorder and caseness, and the pooled mean severity of depressive symptoms, as well as the demographic, illness, functional and treatment correlates of depressive psychopathology in FES.

METHODS

This systematic review, meta-analysis and meta-regression was prospectively registered (CRD42018084856) and conducted in accordance with PRISMA and MOOSE guidelines.

RESULTS

Forty studies comprising 4041 participants were included. The pooled prevalence of depressive disorder and caseness was 26.0% (seven samples, N = 855, 95% CI 22.1-30.3) and 43.9% (11 samples, N = 1312, 95% CI 30.3-58.4), respectively. The pooled mean percentage of maximum depressive symptom severity was 25.1 (38 samples, N = 3180, 95% CI 21.49-28.68). Correlates of depressive psychopathology were also found.

CONCLUSIONS

At least one-quarter of individuals with FES will experience, and therefore require treatment for, a full-threshold depressive disorder. Nearly half will experience levels of depressive symptoms that are severe enough to warrant diagnostic investigation and therefore clinical intervention - regardless of whether they actually fulfil diagnostic criteria for a depressive disorder. Depressive psychopathology is prominent in FES, manifesting not only as superimposed comorbidity, but also as an inextricable symptom domain.

Brain findings associated with risperidone in rhesus monkeys: magnetic resonance imaging and pathology perspectives

Brain changes associated with risperidone, a dopamine-2/serotonin-2 receptor antagonist, have been documented in rats and humans, but not in nonhuman primates. This study characterized brain changes associated with risperidone in nonhuman primates. Rhesus monkeys were orally administered risperidone in a dose-escalation paradigm up to a maximum tolerated dose of 0.5 mg/kg/day for 3 weeks, or 3 months followed by a 3-month recovery period. Transient and fully reversible neurological signs consistent with risperidone pharmacology were observed. The results of a magnetic resonance imaging evaluation after 3 months of treatment and at the end of the 3-month recovery period showed no meaningful changes in the brain. There were no risperidone-related brain weight changes or gross findings. Histomorphological evaluation of brain sections stained with hematoxylin and eosin, ionized calcium binding adaptor molecule 1 (Iba1), and luxol fast blue/cresyl violet double staining showed no notable differences between control and risperidone groups. However, evaluation of the brain after glial fibrillary acidic protein (GFAP) immunohistochemical staining revealed increased staining in the cell bodies and processes of astrocytes in the putamen without apparent alterations in numbers or distribution. The increase in GFAP staining was present after 3 weeks and 3 months of treatment, but no increase in staining was observed after the 3-month recovery period, demonstrating the reversibility of this finding. The reversible increase in GFAP expression was likely an adaptive, non-adverse response of astrocytes, associated with the pharmacology of risperidone. These observations are valuable considerations in the nonclinical risk assessment of new drug candidates for psychiatric disorders.

Correlation analysis between the morphometric characteristics of the head of nucleus caudatus and the intensity of psychotic manifestation in schizophrenia

Introduction: One of the significant functional disorders of the central nervous system in patients with schizophrenia is the increased activity of the mesolimbic dopaminergic system. By the nigrostriatal pathway, the caudate nucleus is closely related to other dopaminergic systems of the brain. Since the function of caudate nucleus relies on the action of Dopamine in the brain; the role of this anatomical structure in the pathogenesis of schizophrenia is not sufficiently clarified. The aim of this paper was to examine whether the caudate nucleus participates in the modulation of the intensity of psychotic manifestations in schizophrenia. Patients and Methods: The study included a total of thirty-one patients with schizophrenia. Diagnosis of the schizophrenia was based on the DSM-IV criterion (Diagnostic and Statistical Manual of Mental Disorders, fourth edition), and the intensity of psychotic manifestations was evaluated by using Brief Psychiatric Rating Scale (BPRS). The size of the caudate nucleus was determined on axial non-contrast CT images on the surface of the largest cross-section using AutoCAD 2007 digital morphometry. The statistical data were processed by the SPSS 16.0 program package. The statistical conclusions are presented on the basis of two-tail p < 0.05. Results: In this study, we have observed a negative correlation between the area as well as the perimeter of the left caudate nucleus head section and the intensity of the psychotic manifestations (area: regression coefficient B = -0.17, p = 0.050, perimeter: regression coefficient B = -0.010, p = 0.012). On the right hemisphere of the brain we observed only a negative correlation of the intensity of the psychotic manifestations from the perimeter of the head section of caudate nucleus (regression coefficient B = -0.013, p = 0.011). Conclusion: In our research we found that the higher intensity of psychotic manifestations in schizophrenia was accompanied with the smaller area and the perimeter of left caudate head as well as the smaller perimeter of the head of right caudate nucleus. The finding of the dependence of the intensity of psychotic manifestations on the perimeter of the right caudate head and not on its area speaks in favor of the caudate head surface deformations as one of the markers of intensity of psychotic manifestations in patients with schizophrenia

Immediate-Early Genes Modulation by Antipsychotics: Translational Implications for a Putative Gateway to Drug-Induced Long-Term Brain Changes

An increasing amount of research aims at recognizing the molecular mechanisms involved in long-lasting brain architectural changes induced by antipsychotic treatments. Although both structural and functional modifications have been identified following acute antipsychotic administration in humans, currently there is scarce knowledge on the enduring consequences of these acute changes. New insights in immediate-early genes (IEGs) modulation following acute or chronic antipsychotic administration may help to fill the gap between primary molecular response and putative long-term changes. Moreover, a critical appraisal of the spatial and temporal patterns of IEGs expression may shed light on the functional "signature" of antipsychotics, such as the propensity to induce motor side effects, the potential neurobiological mechanisms underlying the differences between antipsychotics beyond D2 dopamine receptor affinity, as well as the relevant effects of brain region-specificity in their mechanisms of action. The interest for brain IEGs modulation after antipsychotic treatments has been revitalized by breakthrough findings such as the role of early genes in schizophrenia pathophysiology, the involvement of IEGs in epigenetic mechanisms relevant for cognition, and in neuronal mapping by means of IEGs expression profiling. Here we critically review the evidence on the differential modulation of IEGs by antipsychotics, highlighting the association between IEGs expression and neuroplasticity changes in brain regions impacted by antipsychotics, trying to elucidate the molecular mechanisms underpinning the effects of this class of drugs on psychotic, cognitive and behavioral symptoms.

Changes in White Matter Organization in Adolescent Offspring of Schizophrenia Patients

Schizophrenia is associated with frontostriatal network impairments underlying clinical and cognitive symptoms. We previously found disruptions in anatomical pathways, including the tract connecting the left nucleus accumbens and left dorsolateral prefrontal cortex (DLPFC). Similar deficits are observed in unaffected siblings of schizophrenia patients, indicating that these deficits are linked to a genetic vulnerability for the disorder. Frontostriatal tract disruptions may arise during adolescence, preceding the clinical manifestation of the disorder. However, to date, no studies have been performed to investigate frontostriatal tract connections in adolescents who are at increased familial risk for schizophrenia. In this study, we investigate the impact of familial risk on frontostriatal tract connections using diffusion tensor imaging in 27 adolescent offspring of schizophrenia patients and 32 matched control adolescents, aged 10-18 years. Mean fractional anisotropy (FA) was calculated for the tracts connecting the striatum (caudate nucleus, putamen, nucleus accumbens) and frontal cortex regions (DLPFC, medial orbital frontal cortex, inferior frontal gyrus). As expected, based on siblings data, we found an impact of familial risk on frontostriatal development: schizophrenia offspring showed increased FA in the tracts connecting nucleus accumbens and DLPFC as compared with control adolescents. Moreover, while FA increased across age in control adolescents, it did not in schizophrenia offspring. We did not find differences in FA in other frontostriatal tracts. These results indicate altered development of white matter in subjects who are at familial risk for schizophrenia and may precede frontostriatal white matter alterations in adult schizophrenia patients and siblings.

Simultaneous effects on parvalbumin-positive interneuron and dopaminergic system development in a transgenic rat model for sporadic schizophrenia

To date, unequivocal neuroanatomical features have been demonstrated neither for sporadic nor for familial schizophrenia. Here, we investigated the neuroanatomical changes in a transgenic rat model for a subset of sporadic chronic mental illness (CMI), which modestly overexpresses human full-length, non-mutant Disrupted-in-Schizophrenia 1 (DISC1), and for which aberrant dopamine homeostasis consistent with some schizophrenia phenotypes has previously been reported. Neuroanatomical analysis revealed a reduced density of dopaminergic neurons in the substantia nigra and reduced dopaminergic fibres in the striatum. Parvalbumin-positive interneuron occurrence in the somatosensory cortex was shifted from layers II/III to V/VI, and the number of calbindin-positive interneurons was slightly decreased. Reduced corpus callosum thickness confirmed trend-level observations from in vivo MRI and voxel-wise tensor based morphometry. These neuroanatomical changes help explain functional phenotypes of this animal model, some of which resemble changes observed in human schizophrenia post mortem brain tissues. Our findings also demonstrate how a single molecular factor, DISC1 overexpression or misassembly, can account for a variety of seemingly unrelated morphological phenotypes and thus provides a possible unifying explanation for similar findings observed in sporadic schizophrenia patients. Our anatomical investigation of a defined model for sporadic mental illness enables a clearer definition of neuroanatomical changes associated with subsets of human sporadic schizophrenia.

Diminishing striatal activation across adolescent development during reward anticipation in offspring of schizophrenia patients

Schizophrenia is a severe psychiatric disorder associated with impaired fronto-striatal functioning. Similar deficits are observed in unaffected siblings of patients, indicating that these deficits are linked to a familial risk for the disorder. Fronto-striatal deficits may arise during adolescence and precede clinical manifestation of the disorder. However, the development of the fronto-striatal network in adolescents at increased familial risk for schizophrenia is still poorly understood. In this cross-sectional study, we investigate the impact of familial risk on fronto-striatal functioning across age related to reward anticipation and receipt in 25 adolescent offspring of schizophrenia patients (SZ offspring) and 36 age-matched healthy controls (range 10-19years). Subjects performed a reward task while being scanned with functional MRI. Overall response times and the amount of money won did not differ between the groups. Striatal activation during reward anticipation decreased across age in the SZ offspring, while it did not in the healthy controls. Activation in the orbitofrontal cortex during reward receipt did not differ between the groups. These results, taken together with data from adult schizophrenia patients and their siblings, indicate that the diminishing striatal activation across adolescence may signify a familial vulnerability for schizophrenia.