Progressive reduction of temporal lobe structures in childhood-onset schizophrenia

Morphological Abnormalities in Early-Onset Schizophrenia Revealed by Structural Magnetic Resonance Imaging

Schizophrenia is a pathological condition characterized by delusions, hallucinations, and a lack of motivation. In this study, we performed a morphological analysis of regional biomarkers in early-onset schizophrenia, including cortical thicknesses, surface areas, surface curvature, and volumes extracted from T1-weighted structural magnetic resonance imaging (MRI) and compared these findings with a large cohort of neurotypical controls. Results demonstrate statistically significant abnormal presentation of the curvature of select brain regions in early-onset schizophrenia with large effect sizes, inclusive of the pars orbitalis, pars triangularis, posterior cingulate cortex, frontal pole, orbital gyrus, lateral orbitofrontal gyrus, inferior occipital gyrus, as well as in medial occipito-temporal, lingual, and insular sulci. We also observed reduced regional volumes, surface areas, and variability of cortical thicknesses in early-onset schizophrenia relative to neurotypical controls in the lingual, transverse temporal, cuneus, and parahippocampal cortices that did not reach our stringent standard for statistical significance and should be confirmed in future studies with higher statistical power. These results imply that abnormal neurodevelopment associated with early-onset schizophrenia can be characterized with structural MRI and may reflect abnormal and possibly accelerated pruning of the cortex in schizophrenia.

Reduced Hippocampal Volume and Its Relationship With Verbal Memory and Negative Symptoms in Treatment-Naive First-Episode Adolescent-Onset Schizophrenia

Accumulating neuroimaging evidence has shown remarkable volume reductions in the hippocampi of patients with schizophrenia. However, the relationship among hippocampal morphometry, clinical symptoms, and cognitive impairments in schizophrenia is still unclear. In this study, high-resolution structural magnetic resonance imaging data were acquired in 36 patients with adolescent-onset schizophrenia (AOS, age range: 13-18 years) and 30 age-, gender-, and education-matched typically developing controls (TDCs). Hippocampal volume was assessed automatically through volumetric segmentation and measurement. After adjusting for total intracranial volume, we found reduced hippocampal volume in individuals with AOS compared with TDCs, and the hippocampal volume was positively correlated with verbal memory and negatively correlated with negative symptoms in AOS. In addition, mediation analysis revealed the indirect effect of hippocampal volume on negative symptoms via verbal memory impairment. When the negative symptoms were represented by 2 dimensions of deficits in emotional expression (EXP) and deficits in motivation and pleasure (MAP), the indirect effect was significant for EXP but not for MAP. Our findings provide further evidence of hippocampal volume reduction in AOS and highlight verbal memory impairment as a mediator to influence the relationship between hippocampal morphometry and negative symptoms, especially the EXP dimension of negative symptoms, in individuals with AOS.

Age-Related Reduction in Cortical Thickness in First-Episode Treatment-Naïve Patients with Schizophrenia

Substantial evidence supports the neurodevelopmental hypothesis of schizophrenia. Meanwhile, progressive neurodegenerative processes have also been reported, leading to the hypothesis that neurodegeneration is a characteristic component in the neuropathology of schizophrenia. However, a major challenge for the neurodegenerative hypothesis is that antipsychotic drugs used by patients have profound impact on brain structures. To clarify this potential confounding factor, we measured the cortical thickness across the whole brain using high-resolution T1-weighted magnetic resonance imaging in 145 first-episode and treatment-naïve patients with schizophrenia and 147 healthy controls. The results showed that, in the patient group, the frontal, temporal, parietal, and cingulate gyri displayed a significant age-related reduction of cortical thickness. In the control group, age-related cortical thickness reduction was mostly located in the frontal, temporal, and cingulate gyri, albeit to a lesser extent. Importantly, relative to healthy controls, patients exhibited a significantly smaller age-related cortical thickness in the anterior cingulate, inferior temporal, and insular gyri in the right hemisphere. These results provide evidence supporting the existence of neurodegenerative processes in schizophrenia and suggest that these processes already occur in the early stage of the illness.

Childhood-Onset Schizophrenia: Insights from Induced Pluripotent Stem Cells

Childhood-onset schizophrenia (COS) is a rare psychiatric disorder characterized by earlier onset, more severe course, and poorer outcome relative to adult-onset schizophrenia (AOS). Even though, clinical, neuroimaging, and genetic studies support that COS is continuous to AOS. Early neurodevelopmental deviations in COS are thought to be significantly mediated through poorly understood genetic risk factors that may also predispose to long-term outcome. In this review, we discuss findings from induced pluripotent stem cells (iPSCs) that allow the generation of disease-relevant cell types from early brain development. Because iPSCs capture each donor's genotype, case/control studies can uncover molecular and cellular underpinnings of COS. Indeed, recent studies identified alterations in neural progenitor and neuronal cell function, comprising dendrites, synapses, electrical activity, glutamate signaling, and miRNA expression. Interestingly, transcriptional signatures of iPSC-derived cells from patients with COS showed concordance with postmortem brain samples from SCZ, indicating that changes in vitro may recapitulate changes from the diseased brain. Considering this progress, we discuss also current caveats from the field of iPSC-based disease modeling and how to proceed from basic studies to improved diagnosis and treatment of COS.

The research evidence for schizophrenia as a neurodevelopmental disorder

Schizophrenia is a neurodevelopmental disorder that starts very early. In this review we describe the empirical evidence for the neurodevelopmental model. First, by outlining the roots of psychological research that laid the foundation of the model. Thereafter, describing cognitive dysfunction observed in schizophrenia, and the course of cognitive functioning in the illness. Then, research findings that speak for and studies that speak against the view that schizophrenia is a degenerative process is discussed. We find that there is ample evidence that cognitive disturbance is a core element in schizophrenia. However, we have limited understanding of what initiates the abnormal development. This the paper ends with pointing out some of the factors that may trigger the deviant neurocognitive development in schizophrenia.

Amygdala volume mediates the relationship between externalizing symptoms and daily smoking in adolescence: A prospective study

The current study examined amygdala and orbitofrontal cortex (OFC) volumes as mediators of the relationship between externalizing symptoms and daily smoking in adolescence. Externalizing behaviors are among the most robust predictors of adolescent smoking, and there is emerging evidence that volume reductions in the amygdala and OFC are associated with risk for substance misuse as well as aggressive, impulsive, and disinhibited tendencies. Using a prospective longitudinal design, we recruited 109 adolescents who provided data on brain volume and externalizing behaviors at age 12, and on smoking at age 18. Daily smoking at age 18 (n = 27) was predicted by externalizing behaviors (measured by the self-report Child Behavior Checklist, CBCL) as well as smaller right amygdala volumes. Right amygdala volumes mediated the relationship between externalizing symptoms and later smoking. These findings provide important insight into the neurobiological risk factors associated with adolescent smoking, and, more generally, into factors that may be associated with vulnerability to substance use disorders and related psychopathology.

Brain anatomy of symptom stratification in schizophrenia: a voxel-based morphometry study

BACKGROUND

Although some Magnetic Resonance Imaging (MRI) studies have investigated the relationship between clinical severity and neuroanatomical alterations in patients with schizophrenia (SCZ), the biological signature associated with illness severity in schizophrenia is still uncertain. Therefore, this study aims to investigate structural brain abnormalities in SCZ, with particular regards to the identification of potential deficits associated with the severity of illness.

METHODS

In total, 1.5T MRI data were acquired for 61 subjects with SCZ and 59 matched healthy controls (HC). The patient group was divided in two sub-groups based on clinical severity, one composed of 34 mild-to-moderately ill patients, and the other of 27 severely ill patients, and compared with matched HC.

RESULTS

The whole group of patients with SCZ had significantly reduced grey matter (GM) volumes in the left inferior and middle temporal gyrus compared to HC (p < 0.05, pFWE corrected). Furthermore, compared to HC, patients with mild-to-moderate illness showed decreased GM volumes in the inferior and middle temporal gyrus, whereas those with severe illness had reduced GM volumes in the middle temporal gyrus and cerebellum bilaterally (all p < 0.001 uncorrected). No differences were observed between the two sub-groups of patients.

CONCLUSION

The results showed significant GM volume reductions in temporal regions in patients with SCZ compared to matched HC, confirming the role of these regions in the pathophysiology of SCZ. Furthermore, specific cerebellar grey matter volume reductions were identified in patients with severe illness, which may contribute to stratifying patients with SCZ according to their clinical phenotype expression, ultimately helping in guiding targeted therapeutic/rehabilitation interventions.

Progressive brain changes in children and adolescents with early-onset psychosis: A meta-analysis of longitudinal MRI studies

BACKGROUND

Studies on longitudinal brain volume changes in patients with early-onset psychosis (EOP) are particularly valuable for understanding the neurobiological basis of brain abnormalities associated with psychosis. However, findings have not been consistent across studies in this population. We aimed to conduct a meta-analysis on progressive brain volume changes in children and adolescents with EOP.

METHODS

A systematic literature search of magnetic resonance imaging (MRI) studies comparing longitudinal brain volume changes in children and adolescents with EOP and healthy controls was conducted. The annualized rates of relative change in brain volume by region of interest (ROI) were used as raw data for the meta-analysis. The effect of age, sex, duration of illness, and specific diagnosis on volume change was also evaluated.

RESULTS

Five original studies with 156 EOP patients (mean age at baseline MRI in the five studies ranged from 13.3 to 16.6years, 67.31% males) and 163 age- and sex-matched healthy controls, with a mean duration of follow-up of 2.46years (range 2.02-3.40), were included. Frontal gray matter (GM) was the only region in which significant differences in volume change over time were found between patients and controls (Hedges' g -0.435, 95% confidence interval (CI): -0.678 to -0.193, p<0.001). Younger age at baseline MRI was associated with greater loss of temporal GM volume over time in patients as compared with controls (p=0.005). Within patients, a diagnosis of schizophrenia was related to greater occipital GM volume loss over time (p=0.001).

CONCLUSIONS

Compared with healthy individuals, EOP patients show greater progressive frontal GM loss over the first few years after illness onset. Age at baseline MRI and diagnosis of schizophrenia appear to be significant moderators of particular specific brain volume changes.

Neuroimaging findings from childhood onset schizophrenia patients and their non-psychotic siblings

Childhood onset schizophrenia (COS), with onset of psychosis before age 13, is a rare form of schizophrenia that represents a more severe and chronic form of the adult onset illness. In this review we examine structural and functional magnetic resonance imaging (MRI) studies of COS and non-psychotic siblings of COS patients in the context of studies of schizophrenia as a whole. Studies of COS to date reveal progressive loss of gray matter volume and cortical thinning, ventricular enlargement, progressive decline in cerebellar volume and a significant but fixed deficit in hippocampal volume. COS is also associated with a slower rate of white matter growth and disrupted local connectivity strength. Sibling studies indicate that non-psychotic siblings of COS patients share many of these brain abnormalities, including decreased cortical thickness and disrupted white matter growth, yet these abnormalities normalize with age. Cross-sectional and longitudinal neuroimaging studies remain some of the few methods for assessing human brain function and play a pivotal role in the quest for understanding the neurobiology of schizophrenia as well as other psychiatric disorders. Parallel studies in non-psychotic siblings provide a unique opportunity to understand both risk and resilience in schizophrenia.

ERBB4 polymorphism and family history of psychiatric disorders on age-related cortical changes in healthy children

Genetic variations in ERBB4 were associated with increased susceptibility for schizophrenia (SCZ) and bipolar disorders (BPD). Structural imaging studies showed cortical abnormalities in adolescents and adults with SCZ or BPD. However, less is known about subclinical cortical changes or the influence of ERBB4 on cortical development. 971 healthy children (ages 3-20 years old; 462 girls and 509 boys) were genotyped for the ERBB4-rs7598440 variants, had structural MRI, and cognitive evaluation (NIH Toolbox ®). We investigated the effects of ERBB4 variants and family history of SCZ and/or BPD (FH) on cortical measures and cognitive performances across ages 3-20 years using a general additive model. Variations in ERBB4 and FH impact differentially the age-related cortical changes in regions often affected by SCZ and BPD. The ERBB4-TT-risk genotype children with no FH had subtle cortical changes across the age span, primarily located in the left temporal lobe and superior parietal cortex. In contrast, the TT-risk genotype children with FH had more pronounced age-related changes, mainly in the frontal lobes compared to the non-risk genotype children. Interactive effects of age, FH and ERBB4 variations were also found on episodic memory and working memory, which are often impaired in SCZ and BPD. Healthy children carrying the risk-genotype in ERBB4 and/or with FH had cortical measures resembling those reported in SCZ or BPD. These subclinical cortical variations may provide early indicators for increased risk of psychiatric disorders and improve our understanding of the effect of the NRG1-ERBB4 pathway on brain development.

Dysfunctional resting-state connectivities of brain regions with structural deficits in drug-naive first-episode schizophrenia adolescents

OBJECTIVE

Individuals with adolescent-onset schizophrenia (AOS) are a subgroup of patients who present clinical symptoms between 13 and 18years of age. Little is known about neurodevelopmental abnormalities in this patient population. The present study was to examine possible resting-state dysfunctional connectivity of brain regions with altered gray matter volume in AOS.

METHODS

Gray matter volume was investigated by voxel-based morphometry (VBM) analysis. Resting-state functional connectivity analysis was used to examine the correlations between regions with structural deficits and the remaining regions.

RESULTS

Thirty-seven first-episode schizophrenia adolescents and 30 healthy controls were enrolled. Compared to the controls, the patients showed significantly decreased gray matter volumes in the right superior temporal gyrus (STG) and middle temporal gyrus (MTG) (ps<0.05). With the right STG as seed, significantly reduced connectivities were found within the frontal-temporal networks in the patient group (ps<0.05). With the right MTG as seed, the patient group showed significantly reduced connectivities in the default-mode networks and visual networks (ps<0.05). Compared to significant correlations in the controls (p=0.02), the patients had no observed correlations between functional connectivity of the right STG and gray matter volume of this region. Significant positive correlations were found between functional connectivity of the right STG with the left middle frontal gyrus and the Positive and Negative Syndrome Scale total scores (p=0.048) after controlling the confounding variables.

CONCLUSIONS

These findings show dysfunctional resting-state connectivities of the right STG and MTG with decreased gray matter volume in adolescents with AOS, suggesting that neurodevelopmental abnormalities may be present in AOS.

Functional and clinical insights from neuroimaging studies in childhood-onset schizophrenia

Childhood-onset schizophrenia is a rare pediatric onset psychiatric disorder continuous with and typically more severe than its adult counterpart. Neuroimaging research conducted on this population has revealed similarly severe neural abnormalities. When taken as a whole, neuroimaging research in this population shows generally decreased cortical gray matter coupled with white matter connectivity abnormalities, suggesting an anatomical basis for deficits in executive function. Subcortical abnormalities are pronounced in limbic structures, where volumetric deficits are likely related to social skill deficits, and cerebellar deficits that have been correlated to cognitive abnormalities. Structures relevant to motor processing also show a significant alteration, with volumetric increase in basal ganglia structures likely due to antipsychotic administration. Neuroimaging of this disorder shows an important clinical image of exaggerated cortical loss, altered white matter connectivity, and differences in structural development of subcortical areas during the course of development and provides important background to the disease state.

Positive allosteric modulators of metabotropic glutamate 2 receptors in schizophrenia treatment

The past two decades have witnessed a rise in the 'NMDA receptor hypofunction' hypothesis for schizophrenia, a devastating disorder that affects around 1% of the population worldwide. A variety of presynaptic, postsynaptic, and regulatory proteins involved in glutamatergic signaling have thus been proposed as potential therapeutic targets. This review focuses on positive allosteric modulation of metabotropic glutamate 2 receptors (mGlu2Rs) and discusses how recent preclinical epigenetic data may provide a molecular explanation for the discrepant results of clinical studies, further stimulating the field to exploit the promise of mGlu2R as a target for schizophrenia treatment.

Predictors of outcome in early-onset psychosis: a systematic review

Given the global burden of psychotic disorders, the identification of patients with early-onset psychosis (EOP; that is, onset before the age of 18) at higher risk of adverse outcome should be a priority. A systematic search of Pubmed, Embase, and PsycInfo (1980 through August 2014) was performed to identify longitudinal observational studies assessing correlates and/or predictors of clinical, functional, cognitive, and biological outcomes in EOP. Seventy-five studies were included in the review. Using multivariate models, the most replicated predictors of worse clinical, functional, cognitive, and biological outcomes in EOP were premorbid difficulties and symptom severity (especially of negative symptoms) at baseline. Longer duration of untreated psychosis (DUP) predicted worse clinical, functional, and cognitive outcomes. Higher risk of attempting suicide was predicted by greater severity of psychotic illness and of depressive symptoms at the first episode of psychosis. Age at onset and sex were not found to be relevant predictors of outcome in most multivariate models, whereas studies using bivariate analyses yielded inconsistent results. Lower intelligence quotient at baseline predicted lower insight at follow-up, worse functional outcomes, and a diagnostic outcome of schizophrenia. Biological predictors of outcome in EOP have been little studied and have not been replicated. Lower levels of antioxidants at baseline predicted greater brain volume changes and worse cognitive functioning at follow-up, whereas neuroimaging markers such as regional cortical thickness and gray matter volume at baseline predicted remission and better insight at follow-up, respectively. EOP patients with poorer premorbid adjustment and prominent negative symptoms at initial presentation are at risk of poor outcome. They should therefore be the target of careful monitoring and more intensive interventions to address whether the disease course can be modified in this especially severely affected group. Early intervention strategies to reduce DUP may also improve outcome in EOP.

Do schizophrenia patients age early?

The etiopathogenesis of schizophrenia is poorly understood. Within the proposed "neurodegeneration paradigm", observations have been put forth for "accelerated aging" in this disorder. This proposition is largely based on the neuroscience research that demonstrates progressive changes in brain as well as other systemic abnormalities supportive of faster aging process in patients with this disorder. In this review, we have summarized the literature related to the concept of early aging in schizophrenia. These studies include P300 abnormalities & visual motion discrimination, neuroimaging findings, telomere dynamics as well as neuropathology of related brain regions. We also propose a role of vitamin D, neuroimmunological changes and elevated oxidative stress as well as mitochondrial dysfunction in addition to the above factors with 'vitamin-D deficiency' as the central paradox. Put together, the evidence supporting early aging in schizophrenia is compelling and this requires further systematic studies.

Biomarkers in psychosis: an approach to early identification and individualized treatment

Numerous biomarkers for somatic disorders are used in routine medical practice. Yet, despite remarkable advances in mental health research, we are not able to identify biomarkers with established clinical utility for mental disorders such as schizophrenia. While identification and characterization of biomarkers are crucial first steps in this process, their predictive diagnostic and treatment utility need to be better developed for clinical practice. The heterogeneity of psychotic disorders etiologically, pathologically and symptomatically presents both a challenge and an opportunity for the use of biomarkers in clinical practice. Simply said, a single biomarker might not exist that necessitates the search for a biomarker profile. In this review we discuss research findings in light of such an approach. We summarize some examples of emerging biomarkers in early psychosis research and delineate how these can be applied to a clinical setting to inform treatment on an individual basis fostering a personalized treatment approach.

Psychosis effect on hippocampal reduction in schizophrenia

INTRODUCTION

In schizophrenia, disruption of the neurodevelopmental processes may lead to brain changes and subsequent clinical manifestations of the illness. Reports of the progressive nature of these morphological brain changes raise questions about their causes. The possible toxic effects of repeated stressful psychotic episodes may contribute to the disease progression.

OBJECTIVES

To analyze the influence of illness duration and previous psychotic episodes on hippocampal gray matter volume (GMV) in schizophrenia.

METHODS

We performed an analysis of hippocampal GMV correlations with illness duration, number of previous psychotic episodes, and age in 24 schizophrenia patients and 24 matched healthy controls.

RESULTS

We found a cluster of GMV voxels in the left hippocampal tail that negatively correlated with the number of previous psychotic episodes, independent from the effect of age. On the other hand we found no effect of illness duration independent of age on the hippocampal GMV. Finally, we found a cluster of significant group-by-age interaction in the left hippocampal head.

CONCLUSIONS

We found an additive adverse effect of psychotic episodes on hippocampal morphology in schizophrenia. Our findings support toxicity of psychosis concept, together with etiological heterogeneity of brain changes in schizophrenia.

Gray Matter Alterations in Schizophrenia High-Risk Youth and Early-Onset Schizophrenia: A Review of Structural MRI Findings

This article reviews the literature on structural magnetic resonance imaging findings in pediatric and young adult populations at clinical or genetic high-risk for schizophrenia and early-onset schizophrenia. The implications of this research are discussed for understanding the pathophysiology of schizophrenia and for early intervention strategies. The evidence linking brain structural changes in prepsychosis development and early-onset schizophrenia with disruptions of normal neurodevelopmental processes during childhood or adolescence is described. Future directions are outlined for research to address knowledge gaps regarding the neurobiological basis of brain structural abnormalities in schizophrenia and to improve the usefulness of these abnormalities for preventative interventions.

Converging levels of analysis on a genomic hotspot for psychosis: insights from 22q11.2 deletion syndrome

Schizophrenia is a devastating neurodevelopmental disorder that, despite extensive research, still poses a considerable challenge to attempts to unravel its heterogeneity, and the complex biochemical mechanisms by which it arises. While the majority of cases are of unknown etiology, accumulating evidence suggests that rare genetic mutations, such as 22q11.2 Deletion Syndrome (22qDS), can play a significant role in predisposition to the illness. Up to 25% of individuals with 22qDS eventually develop schizophrenia; conversely, this deletion is estimated to account for 1-2% of schizophrenia cases overall. This locus of Chromosome 22q11.2 contains genes that encode for proteins and enzymes involved in regulating neurotransmission, neuronal development, myelination, microRNA processing, and post-translational protein modifications. As a consequence of the deletion, affected individuals exhibit cognitive dysfunction, structural and functional brain abnormalities, and neurodevelopmental anomalies that parallel many of the phenotypic characteristics of schizophrenia. As an illustration of the value of rare, highly penetrant genetic subtypes for elucidating pathological mechanisms of complex neuropsychiatric disorders, we provide here an overview of the cellular, network, and systems-level anomalies found in 22qDS, and review the intriguing evidence for this disorder's association with schizophrenia. This article is part of the Special Issue entitled 'Neurodevelopmental Disorders'.

Volumetric analysis of medial temporal lobe structures in brain development from childhood to adolescence

Puberty is an important stage of development as a child's sexual and physical characteristics mature because of hormonal changes. To better understand puberty-related effects on brain development, we investigated the magnetic resonance imaging (MRI) data of 306 subjects from 4 to 18 years of age. Subjects were grouped into before and during puberty groups according to their sexual maturity levels measured by the puberty scores. An appearance model-based automatic segmentation method with patch-based local refinement was employed to segment the MRI data and extract the volumes of medial temporal lobe (MTL) structures including the amygdala (AG), the hippocampus (HC), the entorhinal/perirhinal cortex (EPC), and the parahippocampal cortex (PHC). Our analysis showed age-related volumetric changes for the AG, HC, right EPC, and left PHC but only before puberty. After onset of puberty, these volumetric changes then correlate more with sexual maturity level, as measured by the puberty score. When normalized for brain volume, the volumes of the right HC decrease for boys; the volumes of the left HC increase for girls; and the volumes of the left and right PHC decrease for boys. These findings suggest that the rising levels of testosterone in boys and estrogen in girls might have opposite effects, especially for the HC and the PHC. Our findings on sex-specific and sexual maturity-related volumes may be useful in better understanding the MTL developmental differences and related learning, memory, and emotion differences between boys and girls during puberty.

Localized differences in caudate and hippocampal shape are associated with schizophrenia but not antipsychotic type

Caudate and hippocampal volume differences in patients with schizophrenia are associated with disease and antipsychotic treatment, but local shape alterations have not been thoroughly examined. Schizophrenia patients randomly assigned to haloperidol and olanzapine treatment underwent magnetic resonance imaging (MRI) at 3, 6, and 12 months. The caudate and hippocampus were represented as medial representations (M-reps); mesh structures derived from automatic segmentations of high resolution MRIs. Two quantitative shape measures were examined: local width and local deformation. A novel nonparametric statistical method, adjusted exponentially tilted (ET) likelihood, was used to compare the shape measures across the three groups while controlling for covariates. Longitudinal shape change was not observed in the hippocampus or caudate when the treatment groups and controls were examined in a global analysis, nor when the three groups were examined individually. Both baseline and repeated measures analysis showed differences in local caudate and hippocampal size between patients and controls, while no consistent differences were shown between treatment groups. Regionally specific differences in local hippocampal and caudate shape are present in schizophrenic patients. Treatment-related related longitudinal shape change was not observed within the studied timeframe. Our results provide additional evidence for disrupted cortico-basal ganglia-thalamo-cortical circuits in schizophrenia.

CLINICAL TRIAL INFORMATION

This longitudinal study was conducted from March 1, 1997 to July 31, 2001 at 14 academic medical centers (11 in the United States, one in Canada, one in the Netherlands, and one in England). This study was performed prior to the establishment of centralized registries of federally and privately supported clinical trials.

Progressive loss of cortical gray matter in schizophrenia: a meta-analysis and meta-regression of longitudinal MRI studies

Cortical gray matter deficits have been found in patients with schizophrenia, with evidence of progression over time. The aim of this study was to determine the extent of progressive cortical gray matter volume changes over time in schizophrenia, their site and time of occurrence, and the role of potential moderators of brain changes. English language articles published between 1 January 1983 and 31 March 2012 in the MEDLINE and EMBASE databases were searched. Longitudinal magnetic resonance imaging studies comparing changes in cortical gray matter volume over time between patients with schizophrenia and healthy controls were included. Hedges g was calculated for each study. Analyses were performed using fixed- and random-effects models. A subgroup analysis was run to explore the pattern of brain changes in patients with first-episode schizophrenia. A meta-regression statistic was adopted to investigate the role of potential moderators of the effect sizes (ESs). A total of 19 studies, analyzing 813 patients with schizophrenia and 718 healthy controls, were included. Over time, patients with schizophrenia showed a significantly higher volume loss of total cortical gray matter, left superior temporal gyrus (STG), left anterior STG, left Heschl gyrus, left planum temporale and posterior STG bilaterally. Meta-analysis of first-episode schizophrenic patients showed a more significant pattern of progressive loss of whole cerebral gray matter volume involving the frontal, temporal and parietal lobes, and left Heschl gyrus compared with healthy controls. Clinical, pharmacologic and neuroradiological variables were found to be significant moderators of brain volume changes in patients with schizophrenia. The meta-analysis demonstrates that progressive cortical gray matter changes in schizophrenia occur with regional and temporal specificity. The underlying pathological process appears to be especially active in the first stages of the disease, affects the left hemisphere and the superior temporal structures more and is at least partly moderated by the type of pharmacological treatment received.

Unique topology of language processing brain network: a systems-level biomarker of schizophrenia

OBJECTIVE

Schizophrenia is a severe and heritable brain disorder. Language impairment has been hypothesized to spur its onset and underlie the characteristic symptoms. In this study, we investigate whether altered topological pattern of the language processing brain network exists and could be a potential biomarker of schizophrenia. We hypothesized that both patients with schizophrenia and the genetic high risk population would show significantly weakened efficiencies of the network hubs for normal language processing, especially at left inferior frontal and bilateral temporal lobes.

METHOD

Language task-based fMRI data from 21 patients with schizophrenia, 22 genetic high risk subjects and 36 controls were analyzed. Graph theoretic and post hoc analyses of the fMRI data, and correlations between the functional network features and scores of language tests were carried out.

RESULTS

Compared to controls, patients with schizophrenia and the high risk subjects showed significantly weakened network hubs in left inferior frontal and right fusiform gyri. A unique topology of super active and intercommunicating network hubs at left fusiform gyrus and right inferior/middle frontal gyri, which were associated with the behavioral language impairment was found in the patient group, compared to the high risk and control groups.

CONCLUSIONS

Aberrant systems-level topology of language processing network, especially significantly weakened network hubs in left inferior frontal and right fusiform gyri, may serve as a candidate biomarker of schizophrenia. Supported by existing findings, the hyperactive left fusiform gyrus communicating with right frontal lobe might be the key neurophysiological component causing hallucinations in schizophrenia. These findings provided a new systems-level diagnostic target for the disorder.

Psychosis in children: diagnosis and treatment

The diagnosis of childhood psychosis raises a host of unresolved problems, despite the Diagnostic and Statistical Manual Of Mental Disorders, 4th edition, Text Revision (DSM-IV-TR) giving identical symptoms and definitions for children, adolescents, and adults. The fantasy lives of children, and issues of developing language and cognition (including retardation), all impair diagnostic accuracy, particularly when differentiating between childhood-onset schizophrenia (COS) (≤12 years), bipolar affective disorder, major depressive disorder, and even obsessive-compulsive disorder and attention-deficit/hyperactivity disorder: the catch-all classification, psychosis not otherwise specified (PNOS), is always available for conundra that prove unsolvable. Typical if nonpathognomonic features include neurocognitive difficulties. Multiple screening instruments and specialized versions of semistructured diagnostic interviews are available. Although smooth-pursuit eye-tracking movements may prove a genetic marker for COS, etiologies are likely to be oligogenetic rather than related to a single gene. No specific biological markers or neuroimages have been identified. As such, psychoses may be indicative of a more general pattern of brain dysfunction. Drug treatments are largely based on the adult literature because of a dearth of controlled data below age 18. There are still no rigorous studies of psychosocial treatments and psychotherapy specific to childhood psychosis.

White matter integrity, language, and childhood onset schizophrenia

BACKGROUND

The heterogeneity of symptoms and cognitive deficits in schizophrenia can be explained by abnormal connectivity between brain regions. Childhood-onset schizophrenia (COS) is a particularly severe form of schizophrenia, with an onset during a key time period for both cerebral pruning and myelination.

METHODS

Diffusion tensor images were acquired from 18 children and adolescents with COS and 25 controls. The COS group was divided into two sub-groups-one with linguistic impairment (LI) and the other without (NLI). The fractional anisotropy (FA), axial (AD), and radial diffusivity (RD) data from the two COS sub-groups were compared to each other and to the controls using tract-based spatial statistics (TBSS) analyses, which is a voxel-based method used to identify regions of white matter abnormalities.

RESULTS

TBSS identified several regions in the left hemisphere where the LI group had increased AD and RD relative to the NLI and the control groups. These areas primarily localized to linguistic tracts: left superior longitudinal fasciculus and left inferior longitudinal fasciculus/inferior fronto-occipital fasciculus. Regions of increased RD overlapped regions of increased AD, with the former showing more pronounced effects.

CONCLUSIONS

Studies of adult-onset schizophrenia typically identify areas of higher RD but unchanged AD; however, normal development studies have shown that while RD decreases are pronounced over this age range, smaller decreases in AD can also be detected. The observed increases in both RD and AD suggest that developmental disturbances affecting the structural connectivity of these pathways are more severe in COS accompanied by severe linguistic impairments.

Effects of aging on the morphologies of Heschl's gyrus and the superior temporal gyrus in schizophrenia: a postmortem study

The etiology of schizophrenia has been proposed to be neurodevelopmental based on neuroimaging and molecular biological studies. If there is neuronal vulnerability based on neurodevelopment failures in schizophrenic brains, then the impact of aging may have a greater effect on schizophrenic brains than on normal brains. To determine the impact of aging on schizophrenic brains, we investigated the age-related morphological changes of the cross-sectional area of the gray matter (GM) in the left Heschl's gyrus (HG) and the left superior gyrus (STG) in 22 schizophrenic and 24 age- and sex-matched normal control postmortem brains two-dimensionally. The subject groups were divided into younger groups (30-54years of age) and older groups (65-84years of age) on the basis of age at death. Both in schizophrenic and control subjects, the GM area in HG and the STG was significantly smaller in the older group than in the younger group, however, no significant differences were observed between the schizophrenic and control subjects. In the STG, the cross-sectional area of the white matter (WM) was also measured. In the older group, the ratio of the GM area to the WM area in the STG was significantly larger in schizophrenic subjects than controls, although there was no significant difference between the schizophrenic and control subjects in the younger group. These findings indicate that the impact of aging has a greater effect on the WM in the STG in schizophrenic subjects than in normal individuals, although the pathological basis is still unclear.

Asymmetry of lexico-semantic processing in schizophrenia changes with disease progression

BACKGROUND

Are anomalies of cerebral asymmetry integral to the disease process? Here, we examined the influence of age, chronicity and age of onset of illness in 34 patients with early onset schizophrenia and 20 controls in relation to structural asymmetries of the temporal lobe and performance asymmetries on a semantic language lexical decision task.

METHODS

Volumetric MRI and a novel divided visual field probe of lateralised lexico-semantic language were assessed in patients with early onset schizophrenia (EOS) and controls. Novel ratios of age-illness overlap and directional asymmetry were developed in order to examine the association of chronicity factors to asymmetry.

RESULTS

Loss of laterality on the lexical decision task and discordant structural asymmetry were correlated with duration of illness but were not seen in younger, less chronic patients. Reduced lateral processing speed, and discordant structural asymmetry were associated with greater proportion of lifetime schizophrenia.

CONCLUSION

Although the conclusions are limited by the cross sectional nature of the study, anomalies of cerebral asymmetry in early onset patients may be an index of disease progression, and reflect directly on the disease process.

Structural brain abnormalities in first-episode psychosis: differences between affective psychoses and schizophrenia and relationship to clinical outcome

OBJECTIVES

  Several studies have described volumetric brain abnormalities in first-episode psychosis. The extent to which these differ in patients with schizophrenia and affective psychoses, or are related to subsequent clinical outcome, is unclear. We examined volumetric magnetic resonance imaging (MRI) abnormalities in young patients with a first episode of psychosis, and compared these volumetric abnormalities in patients with schizophrenia versus affective psychosis. We then assessed whether baseline MRI abnormalities in the entire sample predicted subsequent clinical outcome.

METHODS

  A total of 28 adolescent patients with first-episode psychosis and 20 age-matched healthy volunteers were scanned using a 1.5 T scanner. MRI data were processed and analysed using voxel-based morphometry (VBM). We assessed clinical outcome three years after the initial scan.

RESULTS

  Patients had smaller grey matter (GM) volumes than controls in frontal, insular, parietal, and cerebellar cortex. Patients with an affective psychosis had greater GM volume in the right posterior cingulate than both controls and patients with schizophrenia, but less GM volume in the left cerebellum and insula. In the sample as a whole, smaller right hippocampus GM volume was associated with poor clinical outcome at three-year follow-up.

CONCLUSIONS

  Volumetric brain abnormalities are evident in young adults presenting with a first episode of both affective psychoses and schizophrenia, but there are also significant differences between these two patient groups. Clinical outcome after the first episode may be related to the severity of volumetric abnormalities at presentation.

Longitudinal changes in brain structure following the first episode of psychosis

Both schizophrenia and bipolar disorder have been associated with progressive changes in grey matter (GM) volume. However, the temporal trajectories of these changes are poorly understood. The aim of this study was to assess longitudinal changes in grey matter volume subsequent to the first episode of schizophrenia and of affective psychoses. Adolescent patients with a first episode psychosis (n=26) were scanned twice using magnetic resonance imaging, at first presentation and after a 3-year follow-up period. An age-matched group of healthy volunteers (n=17) was scanned at the same time points. Within-group and between-group changes in regional grey matter volume were examined using voxel-based morphometry. There were significant group by time interactions (p(FDRcorr)<0.05) in the frontal, temporal, parietal, cerebellar cortex, and in the thalamus, mainly reflecting longitudinal reductions in the controls but not in the patients. Subdivision of the patient group revealed that there were similar longitudinal reductions in patients with affective psychoses as in the controls but no volumetric changes in patients with schizophrenia. Psychosis with onset in adolescence or early adulthood may be associated with a delay or a loss of longitudinal reductions in regional grey matter volume that normally occur at this stage of development. These changes may be specific to schizophrenia.

Abnormal structure or function of the amygdala is a common component of neurodevelopmental disorders

The amygdala, perhaps more than any other brain region, has been implicated in numerous neuropsychiatric and neurodevelopmental disorders. It is part of a system initially evolved to detect dangers in the environment and modulate subsequent responses, which can profoundly influence human behavior. If its threshold is set too low, normally benign aspects of the environment are perceived as dangers, interactions are limited, and anxiety may arise. If set too high, risk taking increases and inappropriate sociality may occur. Given that many neurodevelopmental disorders involve too little or too much anxiety or too little of too much social interaction, it is not surprising that the amygdala has been implicated in many of them. In this chapter, we begin by providing a brief overview of the phylogeny, ontogeny, and function of the amygdala and then appraise data from neurodevelopmental disorders which suggest amygdala dysregulation. We focus on neurodevelopmental disorders where there is evidence of amygdala dysregulation from postmortem studies, structural MRI analyses or functional MRI. However, the results are often disparate and it is not totally clear whether this is due to inherent heterogeneity or differences in methodology. Nonetheless, the amygdala is a common site for neuropathology in neurodevelopmental disorders and is therefore a potential target for therapeutics to alleviate associated symptoms.

Course of neurocognitive deficits in the prodrome and first episode of schizophrenia

Understanding the trajectory of cognitive changes in the development of schizophrenia may shed light on the neurodevelopmental processes in the beginning stage of illness. Subjects at risk for psychosis (AR, n = 48), patients in their first episode of schizophrenia (FE, n = 20), and normal comparison subjects (n = 29) were assessed on a neurocognitive battery at baseline and at a 6-month follow-up. There were significant group differences across all cognitive domains as well as a significant group by time interaction in the verbal learning domain. After statistically controlling for practice effects and regression to the mean, a high proportion of FE subjects showed an improvement in verbal learning, and a significant number of AR subjects improved in general intelligence. Moreover, a higher than expected percentage of FE subjects, as well as AR subjects who later converted to psychosis, showed a deterioration in working memory and processing speed. These inconsistent trajectories suggest that some domains may improve with stabilization in the early stages of psychosis, whereas others may decline with progression of the illness, indicating possible targets for cognitive remediation strategies and candidate vulnerability markers for future psychosis.

Effects of clozapine and olanzapine on cortical thickness in childhood-onset schizophrenia

BACKGROUND

Little is known about the effects of antipsychotic medications on gray matter (GM) in schizophrenia. Although clozapine remains the most effective antipsychotic medication in treatment-refractory cases, it is unknown whether it has a differential effect on GM development.

METHODS

In an exploratory analysis, we used automated cortical thickness measurements and prospectively scanned childhood-onset schizophrenia (COS) patients who were maintained on one medication. Two atypical antipsychotic medications, clozapine (n=12, 37 scans) and olanzapine (n=12, 33 scans) were compared with respect to effects on cortical development, in contrast to GM trajectories of matched controls.

RESULTS

There were no significant differences in the trajectories of cortical thickness between the two treatment groups with the exception of a small circumscribed area in the right prefrontal cortex, where the olanzapine group showed thicker cortex. As expected, both groups showed thinner GM compared to matched controls.

CONCLUSIONS

Although these analyses do not rule out effects of antipsychotic medications on GM development in schizophrenia, they show no differential effect between clozapine and olanzapine on GM trajectory.

Is there a degenerative process going on in the brain of people with Schizophrenia?

Schizophrenia is a biological and behavioural disorder which manifests itself in neurocognitive dysfunctions. The question of whether these key characteristics of the disorder are due to schizophrenia being a degenerative disorder has been discussed for more than 100 years. Neuropsychological data indicate that neurocognitive functions are relatively stable over time after illness onset. Several studies show that there is a decline in neurocognitive functioning prior to and in connection with onset of illness. There is no convincing evidence, however, that there is a progressive neurodegenerative process after onset of illness. Morphological data, on the other hand, indicate a degenerative process. Several novel longitudinal studies indicate a rapid reduction of vital brain tissues after onset of illness. In this paper some ideas about compensatory reactions and Cognitive Reserve Theory is outlined as possible explanations of the recent magnetic resonance imaging studies that show structural changes in the brain after the onset of schizophrenia, at the same time as cognitive functioning does not become more impaired. Determining whether schizophrenia is a neurodegenerative illness with progressive structural changes in the brain after debut of the illness, or a neurodevelopmental disorder starting in early life, is of significant importance for understanding the pathophysiology of the illness and its treatments.

Workshop on defining the significance of progressive brain change in schizophrenia: December 12, 2008 American College of Neuropsychopharmacology (ACNP) all-day satellite, Scottsdale, Arizona. The rapporteurs' report

In 1990 a satellite session of the American College of Neuropsychopharmacology (ACNP) Annual Meeting was held that focused on the question of whether progressive changes in brain structure occur in schizophrenia and this session raised considerable controversy. Eighteen years later, on December 12, 2008, after much data have since accumulated on this topic, a group of approximately 45 researchers gathered after the annual ACNP meeting to participate in a similar workshop on several unresolved questions still remaining: (1) How strong and consistent is the evidence? (2) Is there anatomic specificity to changes and is it disease specific or subject specific? (3) What is the time course? (4) What is the underlying pathophysiology (i.e. is it central to the disease process or is it due to neuroleptic treatment or other epiphenomena? (5) What is its clinical significance? and (6) Are there treatment implications? The day was chaired by Lynn E. DeLisi and co-chaired by Stephen J. Wood. Christos Pantelis and Jeffrey A. Lieberman extensively helped with its planning. The ACNP assisted in its organization as an official satellite of its annual meeting and several pharmaceutical companies provided support with unrestricted educational grants. The following is a summary of the sessions as recounted by rapporteurs whose job was to record as closely as possible the outcome of discussions on the above outlined questions.

Superior temporal gyrus volume change in schizophrenia: a review on region of interest volumetric studies

Imaging studies of schizophrenia (SCZ) have repeatedly demonstrated volume differences in superior temporal gyrus (STG) and its subregions. Among them, some studies employed the Region of Interest (ROI) method. We carried out a systematic review of the published literature on STG volumetry MRI studies to examine the potential of ROI method for identifying specific structural differences and correlations with clinical variables including hallucinations and thought disorder symptoms in SCZ. Forty-six studies were identified as suitable for review and analysis including 1444 patients with SCZ and 1327 controls. Female and left-handed subjects are under-represented in the literature and insight from sex and handedness differences may be lost. Thirty-five studies reported significant differences in STG or subregional volumes including bilateral or unilateral ROI, and volume reduction was the most common change in SCZ. Thirty studies reported correlations between volume changes and clinical symptoms or syndromes and 18 found positive results. Among them, left STG or subregions appear to be more involved in the generation of hallucinations and thought disorder than right side. The majority of five follow-up studies found evidence of progressive changes in volumes. Clinical heterogeneity, MRI acquisition parameters, anatomical landmarks for ROI, and sample characteristics, are likely to be the main factors leading to heterogeneous results. Clearly this research links pathophysiological changes in the STG with the development of hallucinations and thought disorder in patients with SCZ, especially in the left side. There is a suggestion that these changes may be progressive but this requires more thorough and comprehensive assessment.

Is schizophrenia a neurodegenerative disorder?

Schizophrenia is a biological and behavioural disorder, which manifests itself in neurocognitive dysfunction. The question of whether this key characteristic of the disorder is related to schizophrenia being a degenerative disorder has been discussed for more than 100 years. Neuropsychological data indicate that neurocognitive functions are relatively stable over time after illness onset, whereas morphological data indicate a degenerative process. Determining whether schizophrenia is a neurodegenerative illness with progressive structural changes in the brain after debut of the illness, or a neurodevelopmental disorder starting in early life, is of significant importance for understanding the pathophysiology of the illness and its treatments. The aim of the study was to review the current literature on findings that indicate a degenerative process, as well as findings that go against a degenerative process. Several studies show that there is a decline in neurocognitive functioning prior to and in connection with onset of illness. There is no convincing evidence, however, that there is a progressive neurodegenerative process after onset of illness. We cannot provide a definite answer as to whether schizophrenia is a degenerative disorder in the sense of a progressive degeneration after illness onset. Some ideas about compensatory reactions and Cognitive Reserve Theory is outlined as possible explanations of the recent MR studies that show clear-cut structural changes in the brain after onset, at the same time as cognitive functioning does not become more impaired. If schizophrenia is degenerative, the accessibility of psychological treatments will be limited.

Voxel-based structural magnetic resonance imaging (MRI) study of patients with early onset schizophrenia

BACKGROUND

Investigation into the whole brain morphology of early onset schizophrenia (EOS) to date has been sparse. We studied the regional brain volumes in EOS patients, and the correlations between regional volume measures and symptom severity.

METHODS

A total of 18 EOS patients (onset under 16 years) and 18 controls matched for age, gender, parental socioeconomic status, and height were examined. Voxel-based morphometric analysis using the Brain Analysis Morphological Mapping (BAMM) software package was employed to explore alterations of the regional grey (GM) and white matter (WM) volumes in EOS patients. Symptoms were assessed using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

EOS patients had significantly reduced GM volume in the left parahippocampal, inferior frontal, and superior temporal gyri, compared with the controls. They also had less WM volume in the left posterior limb of the internal capsule and the left inferior longitudinal fasciculus. The positive symptom score of PANSS (higher values corresponding to more severe symptoms) was negatively related to GM volume in the bilateral posterior cingulate gyrus. The negative symptom score was positively correlated with GM volume in the right thalamus. As for the association with WM volume, the positive symptom score of PANSS was positively related to cerebellar WM (vermis region), and negatively correlated with WM in the brain stem (pons) and in the bilateral cerebellum (hemisphere region).

CONCLUSION

Our findings of regional volume alterations of GM and WM in EOS patients coincide with those of previous studies of adult onset schizophrenia patients. However, in brain regions that had no overall structural differences between EOS patients and controls (that is, the bilateral posterior cingulate gyrus, the right thalamus, the cerebellum, and the pons), within-subject analysis of EOS patients alone revealed that there were significant associations of the volume in these areas and the symptom severity. These findings suggest that at an early stage of the illness, especially for those with onset before brain maturation, a wide range of disturbed neural circuits, including these brain regions that show no apparent morphological changes, may contribute to the formation of the symptomatology.

Verbal memory and verbal fluency in adolescents with schizophrenia spectrum disorders

AIM

Although impaired verbal memory and verbal fluency are frequently found in adults with schizophrenia, there has been a paucity of studies investigating adolescents with schizophrenia. Thus, the aim of the present study was to investigate the main subcomponents of verbal memory and verbal fluency in adolescents with schizophrenia spectrum disorders.

METHODS

Verbal learning and memory and verbal fluency was assessed in 21 adolescents with schizophrenia spectrum disorders (mean age, 15.4 years) compared with 28 healthy adolescents (mean age, 15.1 years).

RESULTS

The patient group performed significantly below healthy controls on measures of learning, delayed recall and on a frequency estimation task. No differences between the groups were found for measures of recognition, retention, implicit memory, or susceptibility to interference. Although they had impaired delayed recall the patients remembered most of what they actually learned. The patient group was impaired on phonological and semantic fluency, but there were no differences between the groups with respect to clustering or switching on the fluency tasks, when controlling for total output. There was no disproportionate impairment in semantic, as compared to phonological fluency, in the patient group.

CONCLUSIONS

Adolescents with schizophrenia spectrum disorders exhibit impairments in verbal learning and verbal fluency, which might have an impact on the individual's everyday functioning.

Structural and diffusion tensor imaging of the fornix in childhood- and adolescent-onset schizophrenia

OBJECTIVE

There is emerging evidence that aberrations in the integrity of cerebral white matter tracts, especially those connected to limbic structures, play a role in the pathophysiology of schizophrenia. The fornix is the primary efferent neural pathway of the hippocampus and has been shown to be abnormal in adults with schizophrenia.

METHOD

High-resolution structural magnetic resonance imaging and diffusion tensor images were obtained on 15 patients with childhood- and adolescent-onset schizophrenia and 15 age- and sex-matched controls. Measures of cross-sectional area and water diffusion properties were obtained on regions of interest of the fornix performed by a trained radiologist.

RESULTS

The volume of the fornix was significantly smaller (10.9%) in children and adolescents with schizophrenia compared to controls (Cohen d = 0.87, p = .025). There were no significant differences between the fractional anisotropy or mean diffusivity between the groups.

CONCLUSIONS

These findings suggest that the early stages of schizophrenia are associated with a decrease in fornix volume without microstructural white matter changes. The volume differences may reflect an early insult to neighboring brain regions (i.e., hippocampus), that could decrease the number of efferent fibers without necessarily disrupting fiber integrity.

Gaze-triggered orienting is reduced in chronic schizophrenia

Patients with schizophrenia have been reported to demonstrate subtle impairment in gaze processing, which in some cases indicates hypersensitivity to gaze, while in others, hyposensitivity. The neural correlate of gaze processing is situated in the superior temporal sulcus (STS), a major portion of which is constituted by the superior temporal gyrus (STG), and may be the underlying dysfunctional neural basis to the abnormal gaze sensitivity in schizophrenia. To identify the characteristics of gaze behavior in patients with chronic schizophrenia, in whom the STG has been reported to be smaller in volume, we tested 22 patients (mean duration of illness 29 years) in a spatial cueing paradigm using two central pictorial gaze cues, both of which effectively triggered attentional orienting in 22 age-matched normal controls. Arrow cues were also employed to determine whether any compromise in schizophrenia, if present, was gaze-specific. Results demonstrated that schizophrenic subjects benefit significantly less from congruent cues than normal subjects, which was evident for gaze cues but not for arrow cues. This finding is suggestive of a relatively gaze-specific hyposensitivity in patients with chronic schizophrenia, a finding that is in line with their clinical symptomatology and that may be associated with a hypoactive STS.

The concept of progressive brain change in schizophrenia: implications for understanding schizophrenia

Kraepelin originally defined dementia praecox as a progressive brain disease, although this concept has received various degrees of acceptance and rejection over the years since his famous published textbooks appeared. This article places an historical perspective on the current renewal of Kraepelin's concept in brain imaging literature that supports progressive brain change in schizophrenia from its earliest stages through its chronic course. It is concluded that a great deal of future research is needed focusing on the longitudinal course of change, the extent to the regions of change within each individual and the underlying mechanism and implications of brain change through functional and neurochemical imaging, combined with structural studies in the same individuals.

Limbic structures and networks in children and adolescents with schizophrenia

Studies of adults with schizophrenia provide converging evidence for abnormalities in the limbic system. Limbic structures that show consistent patient/control differences in both postmortem and neuroimaging studies include the anterior cingulate and hippocampus, although differences in the amygdala, parahippocampal gyrus, and fornix have also been observed. Studies of white matter in children and adolescents with schizophrenia tend to show findings that are more focal than those seen in adults. Interestingly, these focal abnormalities in early-onset schizophrenia tend to be more localized to limbic regions. While it is unclear if these early limbic abnormalities are primary in the etiology of schizophrenia, there is evidence that supports a developmental progression with early limbic abnormalities evolving over time to match the neuroimaging profiles seen in adults with schizophrenia. Alternatively, the aberrations in limbic structures may be secondary to a more widespread or global pathological processes occurring with the brain that disrupt neural transmission. The goal of this article is to provide a review of the limbic system and limbic network abnormalities reported in children and adolescents with schizophrenia. These findings are compared with the adult literature and placed within a developmental context. These observations from neuroimaging studies enrich our current understanding of the neurodevelopmental model of schizophrenia and raise further questions about primary vs secondary processes. Additional research within a developmental framework is necessary to determine the putative etiologic roles for limbic and other brain abnormalities in early-onset schizophrenia.

Bilateral hippocampal volume increases after long-term lithium treatment in patients with bipolar disorder: a longitudinal MRI study

RATIONALE

The majority of volumetric magnetic resonance imaging (MRI) studies of the hippocampus in patients with bipolar disorder (BD) show no differences in hippocampal volume between patients and healthy controls. Significant variability, however, exists in the medication status of patients included in these studies. In particular, treatment with lithium may exert long-term effects on hippocampal volume, influencing cognitive outcomes in BD patients.

OBJECTIVES

To our knowledge, no longitudinal volumetric study has been performed in patients with BD, which would allow for an examination of whether lithium therapy used to treat BD can exert a long-term effect on hippocampal volume.

MATERIALS AND METHODS

We examined the effects of lithium on hippocampal volumes and recollective memory performance over a period of 2 to 4 years in 12 patients with BD who had never received pharmacotherapy before lithium initiation.

RESULTS

We found bilateral increases in volume of the hippocampus over time. We also found some evidence of improvement in verbal memory performance over the 4-year measurement period as assessed by the California Verbal Learning Test.

CONCLUSIONS

Consistent with preclinical literature supporting the neuroprotective effects of lithium, long-term treatment is associated with preservation of recollective memory function and increased hippocampal size in vivo.

Prolongation of P300 latency is associated with the duration of illness in male schizophrenia patients

The association of P300 components with age, illness duration and gender were examined in schizophrenia patients and whether such variables indicate a progressive course. A total of 60 patients with schizophrenia and 70 healthy controls were studied utilizing standard auditory oddball tasks. Both healthy and schizophrenia groups had a significant positive correlation between age and P300 latency. There was also a significant positive correlation between illness duration and P300 latency in the schizophrenia group. The prolonged latency of P300, associated with age or illness duration, was more prominent in male than female schizophrenia subjects. These findings suggest gender differences in disease progression in schizophrenia.

Pathophysiology of early onset schizophrenia

Early onset schizophrenia (with onset before adulthood) represents a rarer and possibly more severe form of the disorder which has received particular attention in the last two decades. Current evidence strongly suggest continuity with adult onset schizophrenia, with phenomenological, cognitive, genetic and neuroimaging data pointing towards similar neurobiological correlates and clinical deficits but worse long term outcome. Future research in early onset cases is likely to increase further our insight into the neurodevelopmental origins of schizophrenia and the complex gene-environment interactions affecting its emergence.

Neuroimaging and emerging psychotic disorders: the Melbourne ultra-high risk studies

Although the underlying neurobiology of emerging psychotic disorders is not well understood, evidence from structural imaging and other studies support the notion that schizophrenia arises as a consequence of both an 'early neurodevelopmental' disturbance, as well as 'late neurodevelopmental' changes occurring during the initial stages of a psychotic illness, including around the time of transition to illness. In line with this, our longitudinal MRI findings in individuals at ultra-high risk for developing a psychotic illness show that there are excessive neuroanatomical changes in those who convert to psychosis. These aberrant changes are observed most prominently in medial temporal and prefrontal lobe regions. In a further series of longitudinal studies in first-episode psychosis, we have identified changes in prefrontal regions that indicate an accelerated loss of grey matter in patients compared to healthy control subjects. We suggest that the available evidence is consistent with the presence of subtle regionally and temporally specific neurobiological changes through the course of psychosis (Pantelis et al., 2005), including: (1) evidence for early (pre- and peri-natal) neurodevelopmental anomalies, (2) evidence for progressive grey matter loss involving medial temporal and orbital prefrontal regions around the time of transition to illness, and (3) evidence of late (post-pubertal) neurodevelopmental changes soon after the onset of psychosis, involving an acceleration of normal brain maturational processes, associated with significant loss of grey matter in dorsal prefrontal regions. The pathological processes underlying such changes remain unclear and may reflect anomalies in genetic and/or other endogenous mechanisms responsible for brain maturation, the adverse effects of intense or prolonged stress, or other environmental factors. These findings suggest that early markers of impending illness may prove difficult to define, and that brain changes in psychosis may better be conceptualized as anomalous trajectories of brain development. Further, active changes during transition to illness may present the potential to intervene and ameliorate these changes with potential benefit clinically.