Pathophysiology of early onset schizophrenia

A unique multi-synaptic mechanism involving acetylcholine and GABA regulates dopamine release in the nucleus accumbens through early adolescence in male rats

Adolescence is characterized by changes in reward-related behaviors, social behaviors, and decision-making. These behavioral changes are necessary for the transition into adulthood, but they also increase vulnerability to the development of a range of psychiatric disorders. Major reorganization of the dopamine system during adolescence is thought to underlie, in part, the associated behavioral changes and increased vulnerability. Here, we utilized fast scan cyclic voltammetry and microdialysis to examine differences in dopamine release as well as mechanisms that underlie differential dopamine signaling in the nucleus accumbens (NAc) core of adolescent (P28-35) and adult (P70-90) male rats. We show baseline differences between adult and adolescent-stimulated dopamine release in male rats, as well as opposite effects of the α6 nicotinic acetylcholine receptor (nAChR) on modulating dopamine release. The α6-selective blocker, α-conotoxin, increased dopamine release in early adolescent rats, but decreased dopamine release in rats beginning in middle adolescence and extending through adulthood. Strikingly, blockade of GABAA and GABAB receptors revealed that this α6-mediated increase in adolescent dopamine release requires NAc GABA signaling to occur. We confirm the role of α6 nAChRs and GABA in mediating this effect in vivo using microdialysis. Results herein suggest a multisynaptic mechanism potentially unique to the period of development that includes early adolescence, involving acetylcholine acting at α6-containing nAChRs to drive inhibitory GABA tone on dopamine release.

The relationship between self-esteem and mental disability in patients with schizophrenia: the mediating role of resilience and the moderating role of gender

This study aims to verify the mediating role of resilience between self-esteem and mental disability and to analyze the moderating role of gender in the relationship between resilience and mental disability in patients with schizophrenia. Patients with schizophrenia have been selected from Harbin Psychiatric (Baiyupao) Hospital and Daqing Third Hospital in Heilongjiang Province from January to December 2021. The study recruited a total of 220 patients with schizophrenia, including 120 males and 100 females to measure their self-esteem, resilience and mental disability. The results were as follows: Self-esteem and resilience are important protective factors that have a buffering effect on mental disability. The mediating effect of resilience on self-esteem and mental disability is stronger in males than in females. The results provide new ideas for delaying mental disability and for formulating intervention programs and applying them to clinical practice. The study indicates that psychiatric medical staff should not only treat the patients with schizophrenia psychotic symptoms but also improve their self-esteem and resilience through effective intervention to reduce the occurrence of mental disability.

Self-Harm Among Forensic Psychiatric Inpatients With Schizophrenia Spectrum Disorders: An Explorative Analysis

The burden of self-injury among offenders undergoing inpatient treatment in forensic psychiatry is substantial. This exploratory study aims to add to the previously sparse literature on the correlates of self-injury in inpatient forensic patients with schizophrenia spectrum disorders (SSD). Employing a sample of 356 inpatients with SSD treated in a Swiss forensic psychiatry hospital, patient data on 512 potential predictor variables were retrospectively collected via file analysis. The dataset was examined using supervised machine learning to distinguish between patients who had engaged in self-injurious behavior during forensic hospitalization and those who had not. Based on a combination of ten variables, including psychiatric history, criminal history, psychopathology, and pharmacotherapy, the final machine learning model was able to discriminate between self-injury and no self-injury with a balanced accuracy of 68% and a predictive power of AUC = 71%. Results suggest that forensic psychiatric patients with SSD who self-injured were younger both at the time of onset and at the time of first entry into the federal criminal record. They exhibited more severe psychopathological symptoms at the time of admission, including higher levels of depression and anxiety and greater difficulty with abstract reasoning. Of all the predictors identified, symptoms of depression and anxiety may be the most promising treatment targets for the prevention of self-injury in inpatient forensic patients with SSD due to their modifiability and should be further substantiated in future studies.

Functional neurodevelopment of working memory in early-onset schizophrenia: A longitudinal FMRI study

Schizophrenia, a debilitating disorder with typical manifestation of clinical symptoms in early adulthood, is characterized by cognitive impairments in executive processes such as in working memory (WM). However, there is a rare case of individuals with early-onset schizophrenia (EOS) starting before their 18th birthday, while WM and its neural substrates are still undergoing maturation. Using the WM n-back task with functional magnetic resonance imaging, we assessed the functional neurodevelopment of WM in adolescents with EOS and age- and gender-matched typically developing controls. Participants underwent neuroimaging in the same scanner twice, once at age 17 and at 21 (mean interscan interval = 4.3 years). General linear model analysis was performed to explore WM neurodevelopmental changes within and between groups. Psychopathological scores were entered in multiple regressions to detect brain regions whose longitudinal functional change was predicted by baseline symptoms in EOS. WM neurodevelopment was characterized by widespread functional reductions in frontotemporal and cingulate brain areas in patients and controls. No between-group differences were found in the trajectory of WM change. Baseline symptom scores predicted functional neurodevelopmental changes in frontal, cingulate, parietal, occipital, and cerebellar areas. The adolescent brain undergoes developmental processes such as synaptic pruning, which may underlie the refinement WM of network. Prefrontal and parietooccipital activity reduction is affected by clinical presentation of symptoms. Using longitudinal neuroimaging methods in a rare diagnostic sample of patients with EOS may help the advancement of neurodevelopmental biomarkers intended as pharmacological targets to tackle WM impairment.

Thalamic Shape Abnormalities Differentially Relate to Cognitive Performance in Early-Onset and Adult-Onset Schizophrenia

Early-onset schizophrenia (EOS) shares many biological and clinical features with adult-onset schizophrenia (AOS), but may represent a unique subgroup with greater susceptibility for disease onset and worsened symptomatology and progression, which could potentially derive from exaggerated neurodevelopmental abnormalities. Neurobiological explanations of schizophrenia have emphasized the involvement of deep-brain structures, particularly alterations of the thalamus, which have been linked to core features of the disorder. The aim of this study was to compare thalamic shape abnormalities between EOS and AOS subjects and determine whether unique behavioral profiles related to these differences. It was hypothesized abnormal thalamic shape would be observed in anterior, mediodorsal and pulvinar regions in both schizophrenia groups relative to control subjects, but exacerbated in EOS. Magnetic resonance T1-weighted images were collected from adult individuals with EOS (n = 28), AOS (n = 33), and healthy control subjects (n = 60), as well as collection of clinical and cognitive measures. Large deformation high-dimensional brain mapping was used to obtain three-dimensional surfaces of the thalamus. General linear models were used to compare groups on surface shape features, and Pearson correlations were used to examine relationships between thalamic shape and behavioral measures. Results revealed both EOS and AOS groups demonstrated significant abnormal shape of anterior, lateral and pulvinar thalamic regions relative to CON (all p < 0.007). Relative to AOS, EOS exhibited exacerbated abnormalities in posterior lateral, mediodorsal and lateral geniculate thalamic regions (p = 0.003). Thalamic abnormalities related to worse episodic memory in EOS (p = 0.03) and worse working memory (p = 0.047) and executive functioning (p = 0003) in AOS. Overall, findings suggest thalamic abnormalities are a prominent feature in both early- and late-onset schizophrenia, but exaggerated in EOS and have different brain-behavior profiles for each. The persistence of these abnormalities in adult EOS patients suggests they may represent markers of disrupted neurodevelopment that uniquely relate to the clinical and cognitive aspects of the illness.

Patterns of Care for Adolescent With Schizophrenia: A Delphi-Based Consensus Study

BACKGROUND

The current conceptualization of schizophrenia as neurodevelopmental disorder should lead to innovative public health policies in terms of a reorganization of the mental health care systems, particularly in the transition from adolescence to adulthood, to reduce personal, familiar, and social costs and burdens. The purpose of the project was to perform a survey among a panel of Italian schizophrenia experts, to share evidence-based information on adolescent schizophrenia and explore the degree of consensus among professionals in the following four macro-areas: early diagnosis; pharmacological treatment; health care system organization and transition process from adolescent to adulthood; and psychosocial interventions.

METHODS

The consensus process consisted of a two-step web-based Delphi method, which took place between June and November 2021. The survey was developed by a panel of four psychiatrists and four child neuropsychiatrists, identified as key opinion leaders (KOLs). The KOLs identified 21 statements involving a total of 70 items with a major need of clarification on early-onset schizophrenia (EOS). The survey was distributed to 86 specialists in psychiatry and child neuropsychiatry.

RESULTS

The results revealed a large agreement among the expert group on all the investigated areas of adolescent schizophrenia patterns of care and management. Consensus was ultimately reached for 67 items of the Delphi survey (95.7%), while negative consensus was reached for 2 items and no consensus was reached for 1 item.

CONCLUSIONS

Overall, results showed a significant gap between the acquired scientific knowledge and clinical practice. In this scenario, it should be necessary to plan specific initiatives at a multiple level, to edit recommendations on clinical decision-making, as well as to prompt changes at the political and organizational levels, also involving scientific societies, patients, and family associations, to overcome the barriers that delay the implementation process.

Extrapolation of Efficacy and Dose Selection in Pediatrics: A Case Example of Atypical Antipsychotics in Adolescents With Schizophrenia and Bipolar I Disorder

Pediatric labeling information for novel atypical antipsychotics can be significantly delayed as the result of time lag between initial drug approval in adults and the completion of pediatric clinical trials. This delay can lead health care providers to rely on limited evidence-based literature to make critical therapeutic decisions for pediatric patients. Effective and scientifically justified dosing recommendations are needed to improve treatment outcomes in pediatric patients with schizophrenia and bipolar I disorder. Extrapolation-based drug development strategies rely on leveraging prior data to reduce evidentiary requirements for newer data in establishing drug efficacy. On January 13, 2020, the US Food and Drug Administration (FDA) released a general advice letter to sponsors highlighting the acceptance of extrapolating efficacy of atypical antipsychotics to pediatric patients. This review provides insight into the FDA's justification for extrapolating efficacy from adult to pediatric patients and provides a rationale for dose selection in pediatric patients with schizophrenia and bipolar I disorder.

Functional outcomes and patient satisfaction following inpatient treatment for childhood-onset schizophrenia spectrum disorders vs non-psychotic disorders in children in the United Kingdom

AIM

The aim of this study was to compare clinical characteristics and treatment outcomes between children with Childhood-onset schizophrenia spectrum disorders (COSS) and children with other severe non-psychotic psychiatric conditions (non-COSS), all admitted to a national mental health inpatient children's unit.

METHODS

We conducted a retrospective study of all children discharged from a national children's inpatient unit in the United Kingdom, between 2009 and 2018. We compared functional and treatment outcomes and satisfaction with treatment in COSS with non-COSS in the whole sample and separately for male and female patients.

RESULTS

A total of 211 children (55% boys) were included in the sample. The mean age on admission was 129.7 months (10.8 years; age range, 6-12).Twenty cases were diagnosed with COSS (9.5%). In the whole sample, COSS patients had significantly lower Children's Global Assessment Scale (CGAS) scores on admission compared to non-COSS (P = .006). There was a trend towards children with COSS as a group having a longer admission (M = 194.6 days, SD = 125.4) compared to non-COSS (M = 135.8 days, SD = 86.2), (P = .053). Females with COSS seemed to have more significant differences compared to females with non-COSS, in particular, longer admissions (P = .016) and worse CGAS scores at discharge (P = .04), whilst in males, these differences seemed to be attenuated.

CONCLUSIONS

Children with COSS have lower functioning at the point of inpatient admission and possibly longer admissions, but similar satisfaction with treatment at discharge from hospital compared with non-COSS. Females with COSS may have worse functional outcomes compared to non-COSS at discharge.

The Maudsley Early Onset Schizophrenia Study: The effect of age of onset and illness duration on fronto-parietal gray matter

Objective

In Early Onset Schizophrenia (EOS; onset before the 18th birthday) late brain maturational changes may interact with disease mechanisms leading to a wave of back to front structural changes during adolescence. To further explore this effect we examined the relationship between age of onset and duration of illness on brain morphology in adolescents with EOS.

Subjects and methods

Structural brain magnetic resonance imaging scans were obtained from 40 adolescents with EOS. We used Voxel Based Morphometry and multiple regressions analyses, implemented in SPM, to examine the relationship between gray matter volume with age of onset and illness duration.

Results

Age of onset showed a positive correlation with regional gray matter volume in the right superior parietal lobule (Brodmann Area 7). Duration of illness was inversely related to regional gray matter volume in the left inferior frontal gyrus (BA 11/47).

Conclusions

Parietal gray matter loss may contribute to the onset of schizophrenia while orbitofrontal gray matter loss is associated with illness duration.

A Meta-analysis of Structural and Functional Brain Abnormalities in Early-Onset Schizophrenia

Early-onset schizophrenia (EOS) patients demonstrate brain changes that are similar to severe cases of adult-onset schizophrenia. Neuroimaging research in EOS is limited due to the rarity of the disorder. The present meta-analysis aims to consolidate MRI and functional MRI findings in EOS. Seven voxel-based morphometry (VBM) and 8 functional MRI studies met the inclusion criteria, reporting whole-brain analyses of EOS vs healthy controls. Activation likelihood estimation (ALE) was conducted to identify aberrant anatomical or functional clusters across the included studies. Separate ALE analyses were performed, first for all task-dependent studies (Cognition ALE) and then only for working memory ones (WM ALE). The VBM ALE revealed no significant clusters for gray matter volume reductions in EOS. Significant hypoactivations peaking in the right anterior cingulate cortex (rACC) and the right temporoparietal junction (rTPJ) were detected in the Cognition ALE. In the WM ALE, consistent hypoactivations were found in the left precuneus (lPreC), the right inferior parietal lobule (rIPL) and the rTPJ. These hypoactivated areas show strong associations with language, memory, attention, spatial, and social cognition. The functional co-activated networks of each suprathreshold ALE cluster, identified using the BrainMap database, revealed a core co-activation network with similar topography to the salience network. Our results add support to posterior parietal, ACC and rTPJ dysfunction in EOS, areas implicated in the cognitive impairments characterizing EOS. The salience network lies at the core of these cognitive processes, co-activating with the hypoactivating regions, and thus highlighting the importance of salience dysfunction in EOS.

Very early-onset psychosis/schizophrenia: Case studies of spectrum of presentation and management issues

Schizophrenia occurs very uncommonly in children younger than 13 years. The disease is preceded by premorbid difficulties, familial vulnerability, and a prodromal phase. The occurrence of positive psychotic symptoms such as delusions and hallucinations depends on the level of cognitive development of child. Furthermore, at times it is very difficult to differentiate the psychopathology and sustain a diagnosis of schizophrenia in view of similarities with disorders such as autism, mood disorders, and obsessive compulsive disorders. Here, we present three case studies with varying presentation of childhood-onset psychosis/schizophrenia and associated management issues.

Dilemmas in the treatment of early-onset first-episode psychosis

Early-onset first-episode psychosis (EOP) is a severe mental disorder that can pose a number of challenges to clinicians, young people and their families. Its assessment and differentiation from other neurodevelopmental and mental health conditions may at times be difficult, its treatment may not always lead to optimal outcomes and can be associated with significant side effects, and its long-term course and prognosis seem to be less favourable compared with the adult-onset disorder. In this paper, we discuss some dilemmas associated with the evaluation and management of EOP and propose approaches that can be used in the clinical decision-making process. A detailed and well-informed assessment of psychotic symptoms and comorbidities, a systematic approach to treatment with minimum possible medication doses and close monitoring of its effectiveness and adverse effects, and multidimensional interventions taking into consideration risks and expectations associated with EOP, are paramount in the achievement of the most favourable outcomes for affected children and young people.

Autism spectrum disorder and schizophrenia: boundaries and uncertainties

Autism and schizophrenia were placed in different diagnostic categories in DSM-III, having previously been considered as related diagnostic entities. New evidence suggests that these disorders show clinical and cognitive deficit overlaps and shared neurobiological characteristics. Furthermore, children presenting with both autism spectrum disorder (ASD) and psychotic experiences may represent a subgroup of ASD more closely linked to psychosis. The study of ASD and childhood schizophrenia, and their clinical boundaries and overlapping pathophysiological characteristics, may clarify their relationship and lead to more effective interventions. This article discusses the relationship through a critical review of current and historical dilemmas surrounding the phenomenology and pathophysiology of these disorders. It provides a framework for working with children and young people with mixed clinical presentations, illustrated by three brief fictional case vignettes.

Gender differences in first onset Schizophrenia spectrum psychoses

BACKGROUND

Mental health profiles differ between boys and girls from puberty onwards. It is not known whether differences also extend to symptom presentation in schizophrenia spectrum disorders. It may be that girls and boys are not treated entirely equally by the professionals.

AIMS

To study gender differences in symptom profiles, family adversities, pathway to care, and characteristics of inpatient treatment at the first episode of diagnosed schizophrenia spectrum disorder (F20-29) among adolescents aged 13-17.

METHODS

A retrospective chart review of all (n = 106) consecutive adolescents diagnosed for the first time with schizophrenia spectrum disorder (F20-29) in a specified catchment area. Girls and boys were compared with regard to sociodemographics, pathways to care, living arrangements, symptom profiles, and treatment received.

RESULTS

During the study period more adolescent girls (n = 70, 66%) than boys (n = 36, 34%) were diagnosed with schizophrenia spectrum (F20-29) psychoses, most commonly F29. Girls were moreover younger (mean age = 15.46) than boys (mean age = 16.62) at admission. Girls more often displayed mood symptoms and boys aggressive behaviours, alcohol abuse problems, and isolation. Family adversities recorded as current stressors were more numerous among girls. Girls were more likely to be referred to specialized after-care than boys.

CONCLUSIONS

The gender differences observed in symptoms presentation are reminiscent of differences encountered in the general adolescent population. Prior to transition to psychosis, girls and boys are equally in contact with psychiatric services due to other (possibly prodromal) symptoms/disorders. Family adversities may be more stressful for girls vulnerable to psychosis than to boys.

Is it still correct to differentiate between early and very early onset psychosis?

OBJECTIVE

It remains unclear whether very early onset psychosis (VEOP; ≤12years of age) and early onset psychosis (EOP; onset 13-17years of age) are homogeneous in their clinical presentation. We investigated the predictive value of age of psychosis onset for severity, functioning and demographic variation by: 1) comparing groups based on traditional cut-offs for age of psychosis onset, and 2) using receiver operating characteristic (ROC)-curve calculations, without a priori age of onset cut-offs.

METHOD

Participants were 88 (45 female, 43 male) children and adolescents with a recent onset of psychosis (age range=6.7-17.5years; M=13.74, SD=2.37).

RESULTS

The VEOP group had significantly shorter duration of untreated illness and untreated psychosis, and lower functioning than the EOP group. The VEOP and EOP groups did not differ significantly on gender proportion, urbanicity, psychotic diagnosis, family history of psychotic disorder, psychotic, depressive and anxiety symptoms or IQ. When applying ROC-curves to the lowest three quartiles of positive psychotic symptoms scores, the optimal age-cut-off was 14.0years (sensitivity=0.62; specificity=0.75). For the highest quartile of functioning scores, the optimal differentiating cut-off for age of psychosis onset was 14.7years (sensitivity=0.71; specificity=0.70).

CONCLUSIONS

Larger samples of patients, assessed at presentation and followed-up, are necessary to clearly examine clinical presentation and outcome as a function of social and neural development to better understand if the differentiation between VEOP and EOP is justified. This will aid the development of predictive diagnostic tools, more accurate prognosis prediction, and age-tailored therapeutic interventions.

College Students: Mental Health Problems and Treatment Considerations

Attending college can be a stressful time for many students. In addition to coping with academic pressure, some students have to deal with the stressful tasks of separation and individuation from their family of origin while some may have to attend to numerous work and family responsibilities. In this context, many college students experience the first onset of mental health and substance use problems or an exacerbation of their symptoms. Given the uniqueness of college students, there is a need to outline critical issues to consider when working with this population. In this commentary, first, the prevalence of psychiatric and substance use problems in college students and the significance of assessing age of onset of current psychopathology are described. Then, the concerning persistent nature of mental health problems among college students and its implications are summarized. Finally, important aspects of treatment to consider when treating college students with mental health problems are outlined, such as the importance of including parents in the treatment, communicating with other providers, and employing of technology to increase adherence. It is concluded that, by becoming familiar with the unique problems characteristic of the developmental stage and environment college students are in, practitioners will be able to better serve them.

Impaired Verbal Learning Is Associated with Larger Caudate Volumes in Early Onset Schizophrenia Spectrum Disorders

Background

Both brain structural abnormalities and neurocognitive impairments are core features of schizophrenia. We have previously reported enlargements in subcortical brain structure volumes and impairment of neurocognitive functioning as measured by the MATRICS Cognitive Consensus Battery (MCCB) in early onset schizophrenia spectrum disorders (EOS). To our knowledge, no previous study has investigated whether neurocognitive performance and volumetric abnormalities in subcortical brain structures are related in EOS.

Methods

Twenty-four patients with EOS and 33 healthy controls (HC) were included in the study. Relationships between the caudate nucleus, the lateral and fourth ventricles volumes and neurocognitive performance were investigated with multivariate linear regression analyses. Intracranial volume, age, antipsychotic medication and IQ were included as independent predictor-variables.

Results

The caudate volume was negatively correlated with verbal learning performance uniquely in the EOS group (r=-.454, p=.034). There were comparable positive correlations between the lateral ventricular volume and the processing speed, attention and reasoning and problem solving domains for both the EOS patients and the healthy controls. Antipsychotic medication was related to ventricular enlargements, but did not affect the brain structure-function relationship.

Conclusion

Enlargement of the caudate volume was related to poorer verbal learning performance in patients with EOS. Despite a 32% enlargement of the lateral ventricles in the EOS group, associations to processing speed, attention and reasoning and problem solving were similar for both the EOS and the HC groups.

Executive Dysfunction among Children with Antipsychotic Treated Schizophrenia

Objective

To investigate the executive function among adolescents with antipsychotic-treated schizophrenia in Child and Adolescent Outpatient Clinic at Cipto Mangunkusumo General Hospital, Jakarta.

Methods

This was a cross sectional study with control group. Case was defined as adolescents with antipsychotic-treated schizophrenia without any mental retardation or other physical illnesses (n=45). The control group consisted of healthy and age-matched adolescents (n=135). Executive function is determined by using Indonesian version of Behavior Rating Inventory of Executive Function (BRIEF-Indonesian version). We used SPSS 16.0 program for windows to calculate the prevalence risk ratio (PRR) and set up the p value <0.05.

Results

Mean of age was 16.27 (standard deviation 1.86) year-old. Most of the case group (95%) has been treated with atypical antipsychotic such as risperidone, aripipripazole, olanzapine, and clozapine. Duration of having antipsychotic medication was ranged from one to 36 months. Adolescents with antipsychotic treated-schizophrenia had higher BRIEF T-score, except for inhibit scale, shift scale and behavior regulation index. The prevalence risk ratio on several clinical scales were higher in children with antipsychotic-treated schizophrenia compared to control group, such as on emotional state (PRR=7.43, 95% confidence interval [CI]=2.38-23.15), initiate scale (PRR=6.32, 95% CI=2.51-15.95), monitor scale (PRR=8.11, 95% CI=2.0-32.86), and behavior regulation index (PRR=4.09, 95% CI=1.05-15.98).

Conclusion

In general, the results showed that adolescents with atypical antipsychotic treated-schizophrenia had higher BRIEF T-score compared, and comparable with their normal group control.

Relative stability of neurocognitive deficits in early onset schizophrenia spectrum patients

In contrast to the findings of progressive structural brain changes in adolescence, longitudinal studies of patients with early onset schizophrenia spectrum disorders (EOS) indicate that neurocognitive deficits are relatively stable over the first years. The aim of this study is to assess neurocognitive functions longitudinally in patients with EOS compared to healthy controls (HC) using the MATRICS Cognitive Consensus Battery (MCCB).

METHODS

Twenty patients with EOS and 41 HC were tested with the MCCB at baseline (T1) and after one (T2) and two years (T3). The mean age for the EOS group was 15.6 (SD=1.8) years, while the mean duration of illness was 1.7 (SD=1.4) years at T1.

RESULTS

The EOS group's neurocognitive performances indicate a stable deficit on most measures. Both the EOS and HC groups showed improved neurocognitive functioning over time on all measures except for the verbal learning domain. There was an interaction between the EOS and HC groups' performance over time on the Trail Making Test A (TMA), a subtest on the processing speed domain.

CONCLUSION

The longitudinal neurocognitive performances measured by the MCCB confirm previous findings of stable deficits in patients with EOS. It is premature to conclude whether the increases in neurocognitive performance reflect developmental processes in adolescence or may be explained by learning effects, or both. As opposed to the other tests in this domain, a stagnation in processing speed as measured by the TMA suggests that the TMA is a particularly sensitive measure of neurodevelopmental deviance in EOS.

[Reactivity of perineuronal astrocytes in the prefrontal cortex in schizophrenia: an ultrastructural morphometric study]

OBJECTIVE

Previously the ultrastructural alterations of astrocytes have been reported in schizophrenia. Reduced dendritic arborization of the neurons in layer 5 of the prefrontal cortex has been found in schizophrenia. Authors hypothesized that the abnormalities in perineuronal astrocytes (PA) might contribute to these neuronal changes. It was aimed to study the ultrastructure of PA in the prefrontal cortex in schizophrenia.

MATERIAL AND METHODS

Postmortem electron microscopic morphometric study of PA was performed in layer 5, area 10 of the prefrontal cortex in 39 cases of schizophrenia and 37 controls.

RESULTS

No significant group differences were found in areas of cell, nucleus, cytoplasm, volume fraction (Vv) of lipofuscin granules and areal density of PA. However, in the subgroup of women with schizophrenia, the areal density of PA was significantly lower and the area of PA was significantly higher as compared to the subgroup of healthy women (-52%, p<0,01; +32%, p<0.05 respectively) and to the subgroup of men with schizophrenia (-56%, p<0,01; +23%, p<0,05 respectively). The area of PA nucleus was negatively correlated with the duration of disease (r= -0.37, p=0.02) and positively with the age of disease onset (ADO) (r=0,47, p<0,01). Areas of PA and of PA nucleus were significantly lower in early ADO (<21 y.o.) as compared to the adult ADO (>21 y.o.) (-24%, p<0.05). Vv of lypofuscin granules was correlated with the age in control group (r=0.52, p=0.001), but not in schizophrenia group (r=0.13, p=0.4).

CONCLUSION

Significant differences in PA reactivity in the prefrontal cortex in the schizophrenia are associated with gender and age at onset of the disease.

Structural connectivity in schizophrenia and its impact on the dynamics of spontaneous functional networks

The neuropathology of schizophrenia remains unclear. Some insight has come from modern neuroimaging techniques, which offer an unparalleled opportunity to explore in vivo the structure and function of the brain. Using functional magnetic resonance imaging, it has been found that the large-scale resting-state functional connectivity (rsFC) in schizophrenia--measured as the temporal correlations of the blood-oxygen-level-dependent (BOLD) signal--exhibit altered network topology, with lower small-world index. The origin of these rsFC alterations and link with the underlying structural connectivity remain unclear. In this work, we used a computational model of spontaneous large-scale brain activity to explore the role of the structural connectivity in the large-scale dynamics of the brain in health and schizophrenia. The structural connectomes from 15 adolescent patients with early-onset schizophrenia and 15 age- and gender-matched controls were built from diffusion tensor imaging data to detect the white matter tracts between 90 brain areas. Brain areas, simulated using a reduced dynamic mean-field model, receive excitatory input from other areas in proportion to the number of fibre tracts between them. The simulated mean field activity was transformed into BOLD signal, and the properties of the simulated functional networks were analyzed. Our results suggest that the functional alterations observed in schizophrenia are not directly linked to alterations in the structural topology. Instead, subtly randomized and less small-world functional networks appear when the brain operates with lower global coupling, which shifts the dynamics from the optimal healthy regime.

Changes in the diagnosed incidence of early onset schizophrenia over four decades

OBJECTIVE

To explore changes in the diagnosed incidence of early onset schizophrenia (EOS) from 1971 to 2010.

METHOD

Examination of incidence rates of schizophrenia in patients under 18 years of age, using a nationwide, population-based, mental health register.

RESULTS

The age-standardized incidence rate (IR) of EOS in the period 1971-2010 was 3.17 (95% CI: 3.16, 3.18) per 100 000 person years in the age group 0-18 years, and 9.10 (95% CI: 9.00, 9.21) in the age group 12-18 years. In the period 1971-1993, the age-standardized IR of EOS was 1.80 (95% CI: 1.79, 1.82) per 100 000 person years in the age group 0-18 years, and 5.02 (95% CI: 4.92, 5.11) in the age group 12-18 years. In the period 1994-2010, the age-standardized IR of EOS was 5.15 (95% CI: 5.10, 5.20) per 100 000 person years in the age group 0-18 years, and 15.73 (95% CI: 15.22, 16.22) in the age group 12-18 years. The IR was higher for males than females in the periods 1971-1993 and 1971-2010, but in the period 1994-2010 the IR was higher for females than males.

CONCLUSION

In recent years, the diagnosed incidence of EOS has increased and the usual male excess has disappeared. The changes in IR could be a result of changes in the diagnostic system, increased awareness of early psychosis or a reflection of actual underlying incidence of the disorder.

Aggressive behaviour and psychosis in a clinically referred child and adolescent sample

BACKGROUND

Despite evidence of an increased risk of violence among adults suffering from psychosis, very little is currently known about the relationship between early onset psychosis and aggressive behaviour. We aimed to identify and examine overlaps between aggressive behaviour and psychosis in a referred child and adolescent sample to assess whether potential risk factors and other associated features of this co-occurring pattern can be identified at a young age.

METHODS

Standardised item sheet data on young people referred to the Child and Adolescent Department of the Maudsley Hospital between 1973 and 2004 were used to contrast three groups: (1) aggressive-only (n = 1,346), (2) psychosis-only (n = 173), and (3) co-occurring aggression and psychosis (n = 39) on a range of comorbid symptoms and potential risk factors.

RESULTS

Co-occurring cases presented with elevated rates of depersonalisation/derealisation, intrusive thoughts and restlessness, and were more likely to have received past treatment compared with both psychosis-only and aggressive-only cases. Although co-occurring cases resembled the psychosis-only group in many domains, including socio-demographic background and rates of emotional symptoms, they differed from 'pure' psychosis cases in having high levels of special educational needs, irritability, non-aggressive antisocial behaviours, as well as being more likely to be from a low social class and have increased contact with police and child care authorities.

CONCLUSIONS

Our findings suggest that it is possible to identify early risk factors for aggression in individuals with psychosis.

Predictors of clozapine response in patients with treatment-refractory schizophrenia: results from a Danish Register Study

We aimed to identify factors associated with greater clozapine response to guide targeted clozapine use. The study was based on data from the Danish Psychiatric Central Research Register and the National Prescription Database including schizophrenia patients initiating clozapine from 1997 to 2006. Cox regression was used to identify predictors of time to psychiatric hospitalization and all-cause discontinuation from first clozapine prescription. In a 2-year mirror-image design, multiple logistic regression models were used to identify predictors of psychiatric hospitalization. Among 633 schizophrenia patients starting clozapine, shorter time to admission was predicted by increasing number of different antipsychotics (hazard ratio [HR], 1.08/trial; confidence interval [CI], 1.01-1.15/trial) and admissions (HR, 1.04/admission; CI, 1.03-1.05/admission) before first clozapine prescription, earlier onset of schizophrenia (HR, 0.98/y; CI, 0.96-0.99/y), and lower clozapine dose (HR, 0.07/100 mg; CI, 0.03-0.13/100 mg). In the 2-year mirror-image model, during clozapine treatment, there was a significant reduction in bed-days (269.9 days [CI, 238.3-287.8 days] to 64.2 days [CI, 53.0-79.3 days], P < 0.001) and admissions (3.4 [CI, 3.1-3.6] to 2.2 [CI, 1.9-2.5], P < 0.011). Being admitted during clozapine treatment was also associated with more antipsychotic trials (odds ratio [OR], 1.11; CI, 1.00-1.22) and admissions before clozapine initiation (OR, 1.08; CI, 1.04-1.11) and female sex (OR, 1.84; CI, 1.31-2.58). Although the study design does not allow any causal inferences, all 3 models suggested a lower number of psychiatric hospitalizations and antipsychotic trials before clozapine initiation to be associated with greater clozapine response.

Increased familiarity of intellectual deficits in early-onset schizophrenia spectrum disorders

OBJECTIVES

Early-onset schizophrenia is considered to be neurobiologically similar to adult-onset forms, although it represents a more severe expression of the disorder. In the present study, we explored putative larger familial vulnerability of intellectual impairments in early-onset schizophrenia spectrum disorders (EOS) when compared to adult-onset (AOS) families.

METHODS

A sample of 340 subjects including schizophrenia spectrum disorder patients, their first degree relatives and age-matched healthy controls was assessed on intelligence quotient (IQ). We used linear regression analysis and intraclass correlation coefficients (ICC) to explore familial aggregation of IQ across age at onset groups.

RESULTS

The relationship between IQ level of patients and their first-degree relatives showed positive linear association (β = 0.43, P < 0.01). High significant familial aggregation was found for intelligence quotient in EOS families (ICC = 0.618, P < 0.01), while AOS families responded to lower estimates (ICC = 0.204, P = 0.26; between ICC comparison z = 1.993, P < 0.05).

CONCLUSIONS

High aggregation of intellectual performance in the EOS group suggests larger familial vulnerability in early-onset forms of the disease when cognitive functions are considered. Within a continuum of psychopathology in schizophrenia spectrum disorders, specific genetic effects are discussed for distinct onset forms that might be in line with a neurodevelopmental model of the disease.

A systematic review of the long-term outcome of early onset schizophrenia

BACKGROUND

The current review analyzes the long-term outcome and prognosis of early onset schizophrenia based on previously published studies in 1980.

METHODS

A systematic search of articles published in the English-language literature after 1980 identified a total of 21 studies, which included 716 patients who were either suffering from early onset schizophrenia (EOS) or both EOS and other psychotic disorders (MIX). The authors of the current review scored the outcome as either "good," "moderate," or "poor." The mean age of onset in these studies was <18 years.

RESULTS

In general, the outcome in studies with EOS is worse than the outcome in MIX studies. Only 15.4% of the patients in EOS studies versus 19.6% of the patients in MIX studies experienced a "good" outcome. In contrast, 24.5% of the patients in EOS studies versus 33.6% in MIX studies experienced a "moderate" outcome, and 60.1% in EOS studies versus 46.8% in MIX studies experienced a "poor" outcome. The authors identified various significant effects on outcome. In EOS, the findings were significantly affected by sample attrition, indicating that in studies with a high dropout rate, fewer patients experienced a "moderate" outcome, and more patients experienced a "poor" outcome; however, the effect sizes were small. Furthermore, the effects were also small and more favourable for specific functioning measures, as opposed to more global measures, small to moderate in terms of worse outcomes for follow-up periods >10 years, small to moderate for more unfavourable outcomes in males, and small to large for worse outcomes in studies including patients diagnosed before 1970.

CONCLUSIONS

In contrast to the adult manifestation, the early manifestation of schizophrenia in childhood and adolescence still carries a particularly poor prognosis. According to these aggregated data analyses, longer follow-up periods, male sex, and patients having been diagnosed before 1970 contribute predominantly to the rather poor course of EOS.

Environmental risk factors and their impact on the age of onset of schizophrenia: Comparing familial to non-familial schizophrenia

BACKGROUND AND AIMS

Several risk factors for schizophrenia have yet been identified. The aim of our study was to investigate how certain childhood and adolescent risk factors predict the age of onset of psychosis in patients with and without a familial component (i.e. a relative with schizophrenia or schizoaffective disorder).

METHODS

Aside from the age of onset of psychosis, we examined the risk factors for schizophrenia including obstetric complications, birth during winter or spring, behavioral deviances or delayed motor and speech development, exposure to adverse life events and exposure to substance use within a group of 100 patients (45 female, 55 male) with a mean age (± standard deviation) of 35.15 ± 13.21.

RESULTS

Birth complications and cannabis abuse are predictors for an earlier onset of schizophrenia in patients with non-familial schizophrenia. No environmental risk factors for an earlier age of onset in familial schizophrenia have been identified.

CONCLUSIONS

Certain environmental risk factors for schizophrenia seem to have an impact on the age of onset of psychosis in non-familial schizophrenia, they do not seem to have an impact on familial schizophrenia.

Epigenetic aberrations in leukocytes of patients with schizophrenia: association of global DNA methylation with antipsychotic drug treatment and disease onset

Even though schizophrenia has a strong hereditary component, departures from simple genetic transmission are prominent. DNA methylation has emerged as an epigenetic explanatory candidate of schizophrenia's nonmendelian characteristics. To investigate this assumption, we examined genome-wide (global) and gene-specific DNA methylation levels, which are associated with genomic stability and gene expression activity, respectively. Analyses were conducted using DNA from leukocytes of patients with schizophrenia and controls. Global methylation results revealed a highly significant hypomethylation in patients with schizophrenia (P<2.0×10(-6)) and linear regression among patients generated a model in which antipsychotic treatment and disease onset explained 11% of the global methylation variance (adjusted R(2)=0.11, ANOVA P<0.001). Specifically, haloperidol was associated with higher ("control-like") methylation (P=0.001), and early onset (a putative marker of schizophrenia severity) was associated with lower methylation (P=0.002). With regard to the gene-specific methylation analyses, and in accordance with the dopamine hypothesis of psychosis, we found that the analyzed region of S-COMT was hypermethylated in patients with schizophrenia (P=0.004). In summary, these data support the notion of a dysregulated epigenome in schizophrenia, which, at least globally, is more pronounced in early-onset patients and can be partly rescued by antipsychotic medication. In addition, blood DNA-methylation signatures show promise of serving as a schizophrenia biomarker in the future.

Age of onset of mental disorders and use of mental health services: needs, opportunities and obstacles

PURPOSE OF REVIEW

In this review, we provide an update of recent studies on the age of onset (AOO) of the major mental disorders, with a special focus on the availability and use of services providing prevention and early intervention.

RECENT FINDINGS

The studies reviewed here confirm previous reports on the AOO of the major mental disorders. Although the behaviour disorders and specific anxiety disorders emerge during childhood, most of the high-prevalence disorders (mood, anxiety and substance use) emerge during adolescence and early adulthood, as do the psychotic disorders. Early AOO has been shown to be associated with a longer duration of untreated illness, and poorer clinical and functional outcomes.

SUMMARY

Although the onset of most mental disorders usually occurs during the first three decades of life, effective treatment is typically not initiated until a number of years later. There is increasing evidence that intervention during the early stages of disorder may help reduce the severity and/or the persistence of the initial or primary disorder, and prevent secondary disorders. However, additional research is needed on effective interventions in early-stage cases, as well as on the long-term effects of early intervention, and for an appropriate service design for those with emerging mental disorders. This will mean not only the strengthening and re-engineering of existing systems, but is also crucial the construction of new streams of care for young people in transition to adulthood.

Isochromosome 13 in a patient with childhood-onset schizophrenia, ADHD, and motor tic disorder

BACKGROUND

A small percentage of all cases of schizophrenia have a childhood onset. The impact on the individual and family can be devastating. We report the results of genetic analyses from a patient with onset of visual hallucinations at 5 years, and a subsequent diagnosis at 9 years of schizophrenia, attention deficit hyperactivity disorder (ADHD) with hyperactivity and impulsivity, and chronic motor tic disorder.

RESULTS

Karyotypic analysis found 45,XX,i(13)(q10) in all cells examined. Alpha satellite FISH of isochromosome 13 revealed a large unsplit centromeric region, interpreted as two centromeres separated by minimal or undetectable short-arm material or as a single monocentric centromere, indicating that the isochromosome likely formed post-zygotically by a short arm U-type or centromeric exchange. Characterization of chromosome 13 simple tandem repeats and Affymetrix whole-genome 6.0 SNP array hybridization found homozygosity for all markers, and the presence of only a single paternal allele in informative markers, consistent with an isodisomic isochromosome of paternal origin. Analysis of two chromosome 13 schizophrenia candidate genes, D-amino acid oxidase activator (DAOA) and 5-hydroxytryptamine (serotonin) receptor 2A (5-HTR2A), failed to identify non-synonymous coding mutations but did identify homozygous risk polymorphisms.

CONCLUSIONS

We report a female patient with childhood-onset schizophrenia, ADHD, and motor tic disorder associated with an isodisomic isochromosome 13 of paternal origin and a 45,XX,i(13)(q10q10) karyotype. We examined two potential mechanisms to explain chromosome 13 involvement in the patient's pathology, including reduction to homozygosity of a paternal mutation and reduction to homozygosity of a paternal copy number variation, but were unable to identify any overtly pathogenic abnormality. Future studies may consider whether epigenetic mechanisms resulting from uniparental disomy (UPD) and the lack of chromosome 13 maternal alleles lead to the patient's features.

Neurodevelopmental liability to schizophrenia: the complex mediating role of age at onset and premorbid adjustment

Large individual variation in the clinical presentation of schizophrenia-spectrum disorders raises key questions regarding their aetiological underpinnings. In this respect, age at onset of the disorder is a particularly interesting marker of liability, as it has been reported to be associated with other signs of developmental compromise, such as male gender, increased presence of familial history of psychosis and poor premorbid adjustment, as well as a more severe clinical outcome in terms of cognition and symptomatology. The association between these variables has encouraged a neurodevelopmental perspective of the aetiological mechanisms involved in the pathophysiology of schizophrenia. However, the complex relationships within neurobiological liability markers, and between these markers and clinical outcome, remain to be understood. In the present study, we used a path-analytic approach to explore: i) the fit of the model to observed data; and both ii) direct and iii) indirect associations between the variables. In a sample of 106 patients with schizophrenia-spectrum disorders, we found a good fit of the model to the observed data, providing further evidence that supports a neurodevelopmental pathway to the disease in a subgroup of patients. However, the most parsimonious model showed complex relationships, where age at onset and premorbid functioning acted as mediators between gender, familial history of psychosis and clinical outcome. These findings refine earlier explanations of the neurobiological basis of schizophrenia, with potential applications in genetic studies based on more homogeneous forms of the disease. We further discuss the putative implications of our results in clinical practice and prevention policies.

Outcome in early-onset schizophrenia revisited: findings from the Early Psychosis Prevention and Intervention Centre long-term follow-up study

OBJECTIVE

To compare the long-term outcome in individuals with early-onset (before age 18) and adult-onset schizophrenia spectrum disorder who were initially diagnosed and treated in the same clinical center.

METHOD

A prospective follow-up study of 723 consecutive first-episode psychosis patients (age range 14 to 30 years) on average 7.4 years after initial presentation to an early psychosis service, the Early Psychosis Prevention and Intervention Centre in Melbourne, Australia. The outcome measures included the Brief Psychiatric Rating Scale, the Schedule for the Assessment of Negative Symptoms, the Beck Depression Inventory, the Global Assessment of Functioning Scale, the Social and Occupational Functioning Assessment Scale, and the Quality of Life Scale.

RESULTS

Follow-up interviews were conducted on 66.9% (484/723) individuals, of whom 75.6% (366/484) received a schizophrenia spectrum disorder diagnosis at baseline. Early-onset schizophrenia spectrum disorder was observed in 11.2% (41/366). At follow-up, individuals with early-onset reported significantly fewer positive symptoms and were characterised by significantly superior functioning on measures assessing global functioning, social-occupational functioning, and community functioning than individuals with adult-onset. The early-onset group also achieved significantly better vocational outcomes and had a more favourable course of illness with fewer psychotic episodes over the last two years prior to follow-up. Finally, when investigated as a continuous variable, younger age at onset significantly correlated with better symptomatic and functional outcomes.

CONCLUSIONS

These results question the assumption that early-onset schizophrenia typically has a poor outcome. Early detection and specialised treatment for the first psychotic episode appear to be more effective at improving long-term functional outcomes in people with early-onset schizophrenia as in those with adult-onset schizophrenia. This possibility and the reasons for it need further investigation.

Age of onset and timing of treatment for mental and substance use disorders: implications for preventive intervention strategies and models of care

PURPOSE OF REVIEW

To provide an update of the recent studies on the age of onset of the major mental illnesses, with a special focus on the prospects for prevention and early intervention.

RECENT FINDINGS

The studies reviewed here confirm previous reports on the age of onset of the major mental disorders. While the behaviour disorders, and certain anxiety disorders, emerge during childhood, most of the high prevalence disorders (anxiety, mood and substance use) emerge during adolescence and early adulthood, as do the psychotic disorders. Early age of onset has been shown to be associated with a longer duration of untreated illness and poorer clinical and functional outcomes.

SUMMARY

Although the onset of most mental disorders usually occurs during the first three decades of life, effective treatment is typically not initiated until a number of years later. Although there is increasing evidence to suggest that intervention during the early stages of a disorder may help reduce the severity and/or the persistence of the initial or primary disorder and prevent secondary disorders, additional research is needed into appropriate treatment for early stage cases as well as the long-term effects of early intervention, and to appropriate service design for those in the early stages of a mental illness. This will mean not only the strengthening and re-engineering of existing systems but also, crucially, the construction of new streams of care for young people in transition to adulthood.

Age, sex and first treatment of schizophrenia in a population cohort

OBJECTIVE

Schizophrenia affects men more than women, but this may not be true at all ages. This study examines the incidence of first hospitalization for treatment of schizophrenia in each sex over different ages.

METHODS

We compared the incidence of first admission for treatment in a cohort of 46,388 males and 43,680 females followed from birth until ages 29-41, using life tables and proportional hazards methods.

RESULTS

Life table estimates of cumulative incidence by age 40 were 1.44% in males and 0.86% in females. For over all ages the relative risk (RR) in males was 1.6 (95% confidence limits=1.4-1.8) compared with females. Before age 17 there was no significant difference between the sexes (RR=0.86, 0.56-1.3). Excess risk in males was observed only from age 17 (RR=1.7, 1.4-1.9). There was no evidence of the incidence in females catching up with that in males, during the 30s.

CONCLUSION

In this population, there was a significant change, over age, in the relative incidence of first hospitalization for schizophrenia between the sexes; the excess incidence in males first developed at age 17.

Brain volumes in psychotic youth with schizophrenia and mood disorders

BACKGROUND

We sought to test the hypothesis that deficits in grey matter volume are characteristic of psychotic youth with early-onset schizophrenia-spectrum disorders (EOSS) but not of psychotic youth with early-onset mood disorders (EOMD).

METHODS

We used magnetic resonance imaging to examine brain volume in 24 psychotic youth (13 male, 11 female) with EOSS (n = 12) or EOMD (n = 12) and 17 healthy controls (10 male, 7 female). We measured the volume of grey and white matter using an automated segmentation program.

RESULTS

After adjustment for age and intracranial volume, whole brain volume was lower in the EOSS patients than in the healthy controls (p = 0.001) and EOMD patients (p = 0.002). The EOSS patients had a deficit in grey matter volume (p = 0.005), especially in the frontal (p = 0.003) and parietal (p = 0.006) lobes, with no significant differences in white matter volume.

LIMITATIONS

The main limitations of our study were its small sample size and the inclusion of patients with depression and mania in the affective group.

CONCLUSION

Adolescents with EOSS have grey matter deficits compared with healthy controls and psychotic adolescents with EOMD. Our results suggest that grey matter deficits are not generally associated with psychosis but may be specifically associated with schizophrenia. Larger studies with consistent methods are needed to reconcile the contradictory findings among imaging studies involving psychotic youth.

The relationship between symptoms and stress in adolescents with schizophrenia

Stress predicts outcomes in adults with schizophrenia, but its effect in adolescents is unknown. We used exploratory data analysis to examine changes in symptoms and to correlate symptoms with stress at 0, 6, 30, and 54 weeks in 40 adolescents with schizophrenia. Symptoms were measured with the Early Signs and Symptoms Scale; stress was measured with the Hassles Scale. From baseline to 54 weeks, symptom severity decreased significantly. Symptom severity and stress correlated significantly at baseline, 30 weeks, and 54 weeks, after controlling for the number of hospitalizations and baseline symptom severity. These results implicate stress in schizophrenia symptoms in adolescents and justify examining stress management for these patients.

From bench to bedside: translating new research from genetics and neuroimaging into treatment development for early-onset schizophrenia

OBJECTIVE

Children and adolescents with schizophrenia share a similar pattern of phenomenological, genetic and cognitive abnormalities to adults with schizophrenia. However, an early-onset of schizophrenia (EOS) (prior to 18 years of age) is associated with a higher frequency of risk indicators associated with schizophrenia (e.g. developmental delays and familial spectrum disorders) and a worse long-term outcome. This overview examines recent research on the neurobiological alterations, possible causes, developmental trajectory and treatment of EOS and attempts to identify gaps in the field.

METHOD

The authors provide a selective review of major findings from genetics, neuroimaging and treatment studies of pediatric schizophrenia that were presented at a workshop sponsored by the National Institute of Mental Health. These data are synthesized in conjunction with preclinical studies into a model of the pathophysiology of EOS.

RESULTS

EOS is associated with a high frequency of cytogenetic abnormalities (e.g. velocardiofacial syndrome, sex chromosome anomalies) and other rare denovo chromosomal aberrations. Brain imaging research in adolescents with EOS has revealed a progressive loss of cortical grey matter post-onset of psychosis and subtle abnormalities in white matter microstructure. Although EOS patients are more likely to be treatment-refractory than their adult counterparts, there are substantial data that this subgroup is particularly responsive to clozapine.

CONCLUSIONS

Genetic or environmental factors operating during adolescence that reduce frontal capacity might contribute to an EOS in susceptible individuals. Additional longitudinal studies of adolescents with schizophrenia are needed to better understand the relationship between structural changes in fronto-limbic regions, stress responsivity, and cognitive and neurochemical development.

Recent diffusion tensor imaging findings in early stages of schizophrenia

PURPOSE OF REVIEW

Several lines of evidence suggest that the normal integration of cerebral function may be compromised in schizophrenia. Abnormalities in white matter tracts, which connect brain regions into functional networks, may be directly relevant to its pathophysiology. Diffusion tensor imaging (DTI) has increasingly been used to study white matter abnormalities in schizophrenia; in this review, we will discuss recent DTI findings focusing on the early stages of the disorder.

RECENT FINDINGS

Deficits in white matter integrity as inferred by DTI appear to be present in the early stages of schizophrenia, even in neuroleptic-naive patients, and may be the result of interaction between illness-related processes and normal development. The pattern of identified abnormalities is not totally consistent across all studies, with frontotemporal, frontoparietal and temporooccipital connections as well as projection fibers and cerebellar white matter being among the affected tracts.

SUMMARY

Recent DTI findings further support the hypothesis of structural dysconnectivity in schizophrenia. The presence of white matter abnormalities early in the course of the illness is suggestive of these being related to the emergence of the disorder.

Why do many psychiatric disorders emerge during adolescence?

The peak age of onset for many psychiatric disorders is adolescence, a time of remarkable physical and behavioural changes. The processes in the brain that underlie these behavioural changes have been the subject of recent investigations. What do we know about the maturation of the human brain during adolescence? Do structural changes in the cerebral cortex reflect synaptic pruning? Are increases in white-matter volume driven by myelination? Is the adolescent brain more or less sensitive to reward? Finding answers to these questions might enable us to further our understanding of mental health during adolescence.

Global and temporal cortical folding in patients with early-onset schizophrenia

OBJECTIVE

Adult-onset schizophrenia has repeatedly been associated with disturbances in the temporal lobes and alterations in cortical folding, which are thought to reflect neurodevelopmental impairment. Early-onset schizophrenia (EOS; onset before 18 years) is considered to involve even more pronounced neurodevelopmental deviance across a wide range of brain structural measures. We hypothesized that overall alteration of cortical folding also applies to EOS, and EOS involves prominent structural aberrations in superior temporal and collateral sulci.

METHOD

Magnetic resonance T1 images of 51 patients with EOS and 59 healthy participants were investigated. A fully automated method was applied to the images to extract, label, and measure the sulcus area in the whole cortex. Cortical folding was assessed by computing global sulcal indices (the ratio between total sulcal area and total outer cortex area) for each hemisphere and local sulcal indices (the ratio between the area of labeled sulcus and total outer cortex area in the corresponding hemisphere) for superior temporal and collateral sulci.

RESULTS

Relative to healthy individuals, patients with EOS had significantly lower global sulcal indices in both hemispheres and a lower local sulcal index in the left collateral sulcus.

CONCLUSIONS

Reduced hemispheric sulcation appears to be a feature of schizophrenia, irrespective of age at onset. Structural aberration involving the left collateral sulcus may contribute to neurobiological substrate of EOS.