Abnormal asymmetries in subcortical brain volume in early adolescents with subclinical psychotic experiences

The associations of peripheral interleukin alterations and hippocampal subfield volume deficits in schizophrenia

The hippocampus is one of the brain regions most vulnerable to inflammatory insults, and the relationships between peripheral inflammation and hippocampal subfields in patients with schizophrenia remain unclear. In this study, forty-six stably medicated patients with schizophrenia and 48 demographically matched healthy controls (HCs) were recruited. The serum levels of IL - 1β, IL-6, IL-10, and IL-12p70 were measured, and 3D high-resolution T1-weighted magnetic resonance imaging was performed. The IL levels and hippocampal subfield volumes were both compared between patients and HCs. The associations of altered IL levels with hippocampal subfield volumes were assessed in patients. Patients with schizophrenia demonstrated higher serum levels of IL-6 and IL-10 but lower levels of IL-12p70 than HCs. In patients, the levels of IL-6 were positively correlated with the volumes of the left granule cell layer of the dentate gyrus (GCL) and cornu Ammonis (CA) 4, while the levels of IL-10 were negatively correlated with the volumes of those subfields. IL-6 and IL-10 might have antagonistic roles in atrophy of the left GCL and CA4. This suggests a complexity of peripheral cytokine dysregulation and the potential for its selective effects on hippocampal substructures, which might be related to the pathophysiology of schizophrenia.

Threat experiences moderate the link between hippocampus volume and depression symptoms prospectively in adolescence

Identifying neuroimaging risk markers for depression has been an elusive goal in psychopathology research. Despite this, smaller hippocampal volume has emerged as a potential risk marker for depression, with recent research suggesting this association is moderated by family income. The current pre-registered study aimed to replicate and extend these findings by examining the moderating role of family income and three dimensions of environmental experience on the link between hippocampus volume and later depression. Data were drawn from the Adolescent Brain Cognitive Development (ABCD) study and were comprised of 6693 youth aged 9-10 years at baseline. Results indicated that psychosocial threat moderated the association between right hippocampus volume and depression symptoms two years later, such that a negative association was evident in low-threat environments (std. beta=0.15, 95% CI [0.05, 0.24]). This interaction remained significant when baseline depression symptoms were included as a covariate, though only in youth endorsing 1 or more depression symptoms at baseline (β = 0.13, 95% CI = [0.03, 0.22]). These results suggest that hippocampus volume may not be a consistent correlate of depression symptoms in high risk environments and emphasize the importance of including measures of environmental heterogeneity when seeking risk markers for depression.

Longitudinal hippocampal subfield development associated with psychotic experiences in young people

Hippocampal volumetric reductions are observed across the psychosis spectrum, with interest in the localisation of these reductions within the hippocampal subfields increasing. Deficits of the CA1 subfield in particular have been implicated in the neuropathophysiology of psychotic disorders. Investigating the trajectory of these abnormalities in healthy adolescents reporting sub-threshold psychotic experiences (PE) can provide insight into the neural mechanisms underlying psychotic symptoms without the potentially confounding effects of a formal disorder, or antipsychotic medication. In this novel investigation, a sample of 211 young people aged 11-13 participated initially in the Adolescent Brain Development study. PE classification was determined by expert consensus at each timepoint. Participants underwent neuroimaging at 3 timepoints, over 6 years. 78 participants with at least one scan were included in the final sample; 33 who met criteria for a definite PE at least once across all the timepoints (PE group), and 45 controls. Data from bilateral subfields of interest (CA1, CA2/3, CA4/DG, presubiculum and subiculum) were extracted for Linear Mixed Effects analyses. Before correction, subfield volumes were found to increase in the control group and decrease in the PE group for the right CA2 and CA2/3 subfields, with moderate to large effect sizes (d = -0.61, and d = -0.79, respectively). Before correction, right subiculum and left presubiculum volumes were reduced in the PE group compared to controls, regardless of time, with moderate effect sizes (d = -0.52, and d = -0.59, respectively). However, none of these effects survived correction. Severity of symptoms were not associated with any of the noted subfields. These findings provide novel insight to the discussion of the role of hippocampal subfield abnormalities in the pathophysiology underlying psychotic experiences.

Subcortical volumetric alterations in four major psychiatric disorders: a mega-analysis study of 5604 subjects and a volumetric data-driven approach for classification

Differential diagnosis is sometimes difficult in practical psychiatric settings, in terms of using the current diagnostic system based on presenting symptoms and signs. The creation of a novel diagnostic system using objective biomarkers is expected to take place. Neuroimaging studies and others reported that subcortical brain structures are the hubs for various psycho-behavioral functions, while there are so far no neuroimaging data-driven clinical criteria overcoming limitations of the current diagnostic system, which would reflect cognitive/social functioning. Prior to the main analysis, we conducted a large-scale multisite study of subcortical volumetric and lateralization alterations in schizophrenia, bipolar disorder, major depressive disorder, and autism spectrum disorder using T1-weighted images of 5604 subjects (3078 controls and 2526 patients). We demonstrated larger lateral ventricles volume in schizophrenia, bipolar disorder, and major depressive disorder, smaller hippocampus volume in schizophrenia and bipolar disorder, and schizophrenia-specific smaller amygdala, thalamus, and accumbens volumes and larger caudate, putamen, and pallidum volumes. In addition, we observed a leftward alteration of lateralization for pallidum volume specifically in schizophrenia. Moreover, as our main objective, we clustered the 5,604 subjects based on subcortical volumes, and explored whether data-driven clustering results can explain cognitive/social functioning in the subcohorts. We showed a four-biotype classification, namely extremely (Brain Biotype [BB] 1) and moderately smaller limbic regions (BB2), larger basal ganglia (BB3), and normal volumes (BB4), being associated with cognitive/social functioning. Specifically, BB1 and BB2-3 were associated with severe and mild cognitive/social impairment, respectively, while BB4 was characterized by normal cognitive/social functioning. Our results may lead to the future creation of novel biological data-driven psychiatric diagnostic criteria, which may be expected to be useful for prediction or therapeutic selection.

Facial and upper-limb movement abnormalities in individuals with psychotic-like experiences: a motion analysis study

Slow movements and irregular muscle contraction have been reported separately in different studies targeting individuals with psychotic-like experiences (PLEs). To date, it remains unknown whether these two movement abnormalities, possibly associated with hypo- and hyper-dopaminergia, respectively, co-existed in one sample with PLEs and interrelated in the early stage of psychotic progression. Therefore, this study was to examine if facial and upper-limb slow movements and irregular muscle contraction co-existed in individuals with PLEs, interrelated, and were associated with PLEs. A total of 26 individuals with PLEs, who were identified using the 16-item Prodromal Questionnaire, and 26 age- and gender-matched healthy controls received the facial and upper-limb movement measurement. A motion capture system was used to record the movement procedure and thus calculate kinematic variables that represented severity of slow movements and irregular muscle contraction. Results showed that facial and upper-limb slow movements and facial irregular muscle contraction existed in individuals with PLEs. For the total sample, slower facial movements were associated with less regular facial muscle contraction; slower upper-limb movements were associated with less regular upper-limb muscle contraction. Slower and less regular facial and upper-limb movements were associated with more severe PLEs. Compensatory changes in dopaminergic neural pathways in response to elevated dopamine might explain connection between slow movements and irregular muscle contraction. Because of the ability to detect facial and upper-limb movement abnormalities objectively and sensitively, motion analysis has great applicability to sensorimotor studies for people in the psychosis continuum.

The contribution of the cingulate cortex: treating depressive symptoms in first-episode drug naïve schizophrenia

Background

Our previous study has shown the cingulate cortex abnormalities in first-episode drug naïve (FEDN) schizophrenia patients with comorbid depressive symptoms. However, it remains largely unknown whether antipsychotics may induce morphometric change in cingulate cortex and its relationship with depressive symptoms. The purpose of this study was to further clarify the important role of cingulate cortex in the treatment on depressive symptoms in FEDN schizophrenia patients.

Method

In this study, 42 FEDN schizophrenia patients were assigned into depressed patients group (DP, n = 24) and non-depressed patients group (NDP, n = 18) measured by the 24-item Hamilton Depression Rating Scale (HAMD). Clinical assessments and anatomical images were obtained from all patients before and after 12-week treatment with risperidone.

Results

Although risperidone alleviated psychotic symptoms in all patients, depressive symptoms were decreased only in DP. Significant group by time interaction effects were found in the right rostral anterior cingulate cortex (rACC) and other subcortical regions in the left hemisphere. After risperidone treatment, the right rACC were increased in DP. Further, the increasing volume of right rACC was negatively associated with improvement in depressive symptoms.

Conclusion

These findings suggested that the abnormality of the rACC is the typical characteristics in schizophrenia with depressive symptoms. It's likely key region contributing to the neural mechanisms underlying the effects of risperidone treatment on depressive symptoms in schizophrenia.

Large-scale analysis of structural brain asymmetries in schizophrenia via the ENIGMA consortium

Left-right asymmetry is an important organizing feature of the healthy brain that may be altered in schizophrenia, but most studies have used relatively small samples and heterogeneous approaches, resulting in equivocal findings. We carried out the largest case-control study of structural brain asymmetries in schizophrenia, with MRI data from 5,080 affected individuals and 6,015 controls across 46 datasets, using a single image analysis protocol. Asymmetry indexes were calculated for global and regional cortical thickness, surface area, and subcortical volume measures. Differences of asymmetry were calculated between affected individuals and controls per dataset, and effect sizes were meta-analyzed across datasets. Small average case-control differences were observed for thickness asymmetries of the rostral anterior cingulate and the middle temporal gyrus, both driven by thinner left-hemispheric cortices in schizophrenia. Analyses of these asymmetries with respect to the use of antipsychotic medication and other clinical variables did not show any significant associations. Assessment of age- and sex-specific effects revealed a stronger average leftward asymmetry of pallidum volume between older cases and controls. Case-control differences in a multivariate context were assessed in a subset of the data (N = 2,029), which revealed that 7% of the variance across all structural asymmetries was explained by case-control status. Subtle case-control differences of brain macrostructural asymmetry may reflect differences at the molecular, cytoarchitectonic, or circuit levels that have functional relevance for the disorder. Reduced left middle temporal cortical thickness is consistent with altered left-hemisphere language network organization in schizophrenia.

Dynamic effects of bilingualism on brain structure map onto general principles of experience-based neuroplasticity

Bilingualism has been linked to structural adaptations of subcortical brain regions that are important for controlling multiple languages. However, research on the location and extent of these adaptations has yielded variable patterns, especially as far as the subcortical regions are concerned. Existing literature on bilingualism-induced brain restructuring has so far largely overseen evidence from other domains showing that experience-based structural neuroplasticity often triggers non-linear adaptations which follow expansion-renormalisation trajectories. Here we use generalised additive mixed models to investigate the non-linear effects of quantified bilingual experiences on the basal ganglia and the thalamus in a sample of bilinguals with a wide range of bilingual experiences. Our results revealed that volumes of the bilateral caudate nucleus and nucleus accumbens were significantly related to bilingual experiences. Importantly, these followed a non-linear pattern, with increases followed by plateauing in the most experienced bilinguals, suggesting that experience-based volumetric increases are only necessary up to a certain level of bilingual experience. Moreover, the volumes of putamen and thalamus were positively predicted by bilingual experiences. The results offer the first direct evidence that bilingualism, similarly to other cognitively demanding skills, leads to dynamic subcortical structural adaptations which can be nonlinear, in line with expansion-renormalisation models of experience-dependent neuroplasticity.

Rhythmic auditory stimulation incorporated in training improved movements in individuals with psychotic-like experiences

Movement abnormalities, including movement slowing and irregular muscle contraction, exist in individuals with psychotic-like experiences (PLEs) and serve as vulnerable factors of developing psychotic diseases in the psychosis continuum. To date scarce studies have developed early intervention programs tackling these initial impairments, which may be caused by basal ganglia alterations, in the early stage of the psychosis course. Rhythmic auditory stimulation (RAS) is a technique of neurological music therapy and has been proved effective in inducing faster movements in patients with psychotic diseases. This pilot study examined if RAS incorporated in functional movement training reduced severity of movement slowing and irregular muscle contraction in individuals with PLEs. Seventeen individuals with PLEs were randomly allocated to receiving RAS or receiving no RAS and underwent daily 40-min movement training (picking up beans) for three weeks. This study used motion analysis to measure movement performance at pretest and posttest. Eighteen age- and gender-matched individuals without PLEs were also recruited to provide data of intact movements. Results showed that RAS may reduce severity of movement slowing and irregular muscle contraction in individuals with PLEs. This pilot study is one of the pioneering studies validating effectiveness of early intervention programs tackling movement abnormalities, which are initial impairments in the psychosis continuum, in individuals with PLEs.

Association between mild traumatic brain injury, brain structure, and mental health outcomes in the Adolescent Brain Cognitive Development Study

BACKGROUND

Children that experience a mild traumatic brain injury (mTBI) are at an increased risk of neural alterations that can deteriorate mental health. We test the hypothesis that mTBI is associated with psychopathology and that structural brain metrics (e.g., volume, area) meaningfully mediate the relation in an adolescent population.

METHODS

We analyzed behavioral and brain MRI data from 11,876 children who participated in the Adolescent Brain Cognitive Development (ABCD) Study. Mixed-effects models were used to examine the longitudinal association between mTBI and mental health outcomes. Bayesian methods were used to investigate brain regions that are intermediate between mTBI and symptoms of poor mental health.

RESULTS

There were 199 children with mTBI and 527 with possible mTBI across the three ABCD Study visits. There was a 7% (IRR = 1.07, 95% CI: 1.01, 1.13) and 15% (IRR = 1.16, 95% CI: 1.05, 1.26) increased risk of emotional or behavioral problems in children that experienced possible mTBI or mTBI, respectively. Possible mTBI was associated with a 17% (IRR: 1.17, 95% CI: 0.99, 1.40) increased risk of experiencing distress following a psychotic-like experience. We did not find any brain regions that meaningfully mediated the relationship between mTBI and mental health outcomes. Analysis of volumetric measures found that approximately 2% to 5% of the total effect of mTBI on mental health outcomes operated through total cortical volume. Image intensity measure analyses determined that approximately 2% to 5% of the total effect was mediated through the left-hemisphere of the dorsolateral prefrontal cortex.

CONCLUSION

Results indicate an increased risk of emotional and behavioral problems in children that experienced possible mTBI or mTBI. Mediation analyses did not elucidate the mechanisms underlying the association between mTBI and mental health outcomes.

Psychotic experiences in the general population, a review; definition, risk factors, outcomes and interventions

Psychotic experiences (PE) are common in the general population, in particular in childhood, adolescence and young adulthood. PE have been shown to be associated with an increased risk for later psychotic disorders, mental disorders, and poorer functioning. Recent findings have highlighted the relevance of PE to many fields of healthcare, including treatment response in clinical services for anxiety & depression treatment, healthcare costs and service use. Despite PE relevance to many areas of mental health, and healthcare research, there remains a gap of information between PE researchers and experts in other fields. With this review, we aim to bridge this gap by providing a broad overview of the current state of PE research, and future directions. This narrative review aims to provide an broad overview of the literature on psychotic experiences, under the following headings: (1) Definition and Measurement of PE; (2) Risk Factors for PE; (3) PE and Health; (4) PE and Psychosocial Functioning; (5) Interventions for PE, (6) Future Directions.

Longitudinal grey matter development associated with psychotic experiences in young people

Background

Gray matter abnormalities are observed across the psychosis spectrum. The trajectory of these abnormalities in healthy adolescents reporting subthreshold psychotic experiences (PEs) may provide insight into the neural mechanisms underlying psychotic symptoms. The risk of psychosis and additional psychopathology is even higher among these individuals who also report childhood adversity/DSM-5 diagnoses. Thus, the aims of this longitudinal study were to investigate PE-related volumetric changes in young people, noting any effects of childhood adversity/DSM-5 diagnosis.

Methods

A total of 211 young people 11 to 13 years of age participated in the initial Adolescent Brain Development study. PE classification was determined by expert consensus at each time point. Participants underwent neuroimaging at 3 time points over 6 years. A total of 76 participants with at least one scan were included in the final sample; 34 who met criteria for PEs at least once across all the time points (PE group) and 42 control subjects. Data from 20 bilateral regions of interest were extracted for linear mixed-effects analyses.

Results

Right hippocampal volume increased over time in the control group, with no increase in the PE group (p = .00352). DSM-5 diagnosis and childhood adversity were not significantly associated with right hippocampal volume. There was no significant effect of group or interaction in any other region.

Conclusions

These findings further implicate right hippocampal volumetric abnormalities in the pathophysiology underlying PEs. Furthermore, as suggested by previous studies in those at clinical high risk for psychosis and those with first-episode psychosis, it is possible that these deficits may be a marker for later clinical outcomes.

Negative symptoms correlate with altered brain structural asymmetry in amygdala and superior temporal region in schizophrenia patients

Negative symptoms play an important role in development and treatment of schizophrenia. However, brain changes relevant to negative symptoms are still unclear. This study examined brain structural abnormalities and their asymmetry in schizophrenia patients and the association with negative symptoms. Fifty-nine schizophrenia patients and 66 healthy controls undertook structural brain scans. Schizophrenia patients were further divided into predominant negative symptoms (PNS, n = 18) and non-PNS (n = 34) subgroups. Negative symptoms were assessed by the Negative Symptom Assessment (NSA). T1-weighted images were preprocessed with FreeSurfer to estimate subcortical volumes, cortical thickness and surface areas, asymmetry Index (AI) was then calculated. MANOVA was performed for group differences while partial correlations in patients were analyzed between altered brain structures and negative symptoms. Compared to healthy controls, schizophrenia patients exhibited thinner cortices in frontal and temporal regions, and decreased leftward asymmetry of superior temporal gyrus (STG) in cortical thickness. Patients with PNS exhibited increased rightward asymmetry of amygdala volumes than non-PNS subgroup. In patients, AI of cortical thickness in the STG was negatively correlated with NSA-Emotion scores (r = -0.30, p = 0.035), while AI of amygdala volume was negatively correlated with NSA-Communication (r = -0.30, p = 0.039) and NSA-Total scores (r = -0.30, p = 0.038). Our findings suggested schizophrenia patients exhibited cortical thinning and altered lateralization of brain structures. Emotion and communication dimensions of negative symptoms also correlated with the structural asymmetry of amygdala and superior temporal regions in schizophrenia patients.

Involvement of cerebellar and subcortical connector hubs in schizophrenia

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Hubs with altered connectivity to multiple networks were identified in patients.

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Identified hubs were located in the cerebellum, midbrain, thalamus, and insula.

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In controls, these hubs were strongly connected with the basal ganglia network.

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Hubs’ connections to large-scale networks were associated with clinical data.

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Their connections were also highly predictive of patients from controls.

Background

Schizophrenia is considered a brain connectivity disorder in which functional integration within the brain fails. Central to the brain’s integrative function are connector hubs, brain regions characterized by strong connections with multiple networks. Given their critical role in functional integration, we hypothesized that connector hubs, including those located in the cerebellum and subcortical regions, are severely impaired in patients with schizophrenia.

Methods

We identified brain voxels with significant connectivity alterations in patients with schizophrenia (n = 76; men = 43) compared to healthy controls (n = 80; men = 43) across multiple large-scale resting state networks (RSNs) using a network metric called functional connectivity overlap ratio (FCOR). From these voxels, candidate connector hubs were identified and verified using seed-based connectivity analysis.

Results

We found that most networks exhibited connectivity alterations in the patient group. Specifically, connectivity with the basal ganglia and high visual networks was severely affected over widespread brain areas in patients, affecting subcortical and cerebellar regions and the regions involved in visual and sensorimotor processing. Furthermore, we identified critical connector hubs in the cerebellum, midbrain, thalamus, insula, and calcarine with connectivity to multiple RSNs affected in the patients. FCOR values of these regions were also associated with clinical data and could classify patient and control groups with > 80 % accuracy.

Conclusions

These findings highlight the critical role of connector hubs, particularly those in the cerebellum and subcortical regions, in the pathophysiology of schizophrenia and the potential role of FCOR as a clinical biomarker for the disorder.

Cortical and Subcortical Structural Morphometric Profiles in Individuals with Nonaffective and Affective Early Illness Psychosis

Research has found strong evidence for common and distinct morphometric brain abnormality profiles in nonaffective psychosis (NAff-P) and affective psychosis (Aff-P). Due to chronicity and prolonged medication exposure confounds, it is crucial to examine structural morphometry early in the course of psychosis. Using Human Connectome Project-Early Psychosis data, multivariate profile analyses were implemented to examine regional profiles for cortical thickness, cortical surface area, subcortical volume, and ventricular volume in healthy control (HC; n = 56), early illness NAff-P (n = 83), and Aff-P (n = 30) groups after accounting for normal aging. Associations with symptom severity, functioning, and cognition were also examined. Group regional profiles were significantly nonparallel and differed in level for cortical thickness (P < .001), with NAff-P having widespread cortical thinning relative to HC and Aff-P and some regions showing greater deficits than others. Significant nonparallelism of group regional profiles was also evident for cortical surface area (P < .006), with Aff-P and N-Aff-P differing from HC and from each other (P < .001). For subcortical volume, there was significant profile nonparallelism with NAff-P having an enlarged left pallidum and smaller accumbens and hippocampus (P < .028), and Aff-P having a smaller accumbens and amygdala (P < .006), relative to HC. NAff-P also had larger basal ganglia compared to Aff-P. Furthermore, NAff-P had enlarged ventricles (P < .055) compared to HC and Aff-P. Additionally, greater ventricular volume was associated with increased manic symptoms in NAff-P and Aff-P. Overall, this study found common and distinct regional morphometric profile abnormalities in early illness NAff-P and Aff-P, providing evidence for both shared and disease-specific pathophysiological processes.

Intra- and interhemispheric symmetry of subcortical brain structures: a volumetric analysis in the aging human brain

Here, we address the hemispheric interdependency of subcortical structures in the aging human brain. In particular, we investigated whether subcortical volume variations can be explained by the adjacency of structures in the same hemisphere or are due to the interhemispheric development of mirror subcortical structures in the brain. Seven subcortical structures in each hemisphere were automatically segmented in a large sample of 3312 magnetic resonance imaging (MRI) studies of elderly individuals in their 70s and 80s. We performed Eigenvalue analysis, and found that anatomic volumes in the limbic system and basal ganglia show similar statistical dependency whether considered in the same hemisphere (intrahemispherically) or different hemispheres (interhemispherically). Our results indicate that anatomic bilaterality of subcortical volumes is preserved in the aging human brain, supporting the hypothesis that coupling between non-adjacent subcortical structures might act as a mechanism to compensate for the deleterious effects of aging.

Multimodal Machine Learning Workflows for Prediction of Psychosis in Patients With Clinical High-Risk Syndromes and Recent-Onset Depression

IMPORTANCE

Diverse models have been developed to predict psychosis in patients with clinical high-risk (CHR) states. Whether prediction can be improved by efficiently combining clinical and biological models and by broadening the risk spectrum to young patients with depressive syndromes remains unclear.

OBJECTIVES

To evaluate whether psychosis transition can be predicted in patients with CHR or recent-onset depression (ROD) using multimodal machine learning that optimally integrates clinical and neurocognitive data, structural magnetic resonance imaging (sMRI), and polygenic risk scores (PRS) for schizophrenia; to assess models' geographic generalizability; to test and integrate clinicians' predictions; and to maximize clinical utility by building a sequential prognostic system.

DESIGN, SETTING, AND PARTICIPANTS

This multisite, longitudinal prognostic study performed in 7 academic early recognition services in 5 European countries followed up patients with CHR syndromes or ROD and healthy volunteers. The referred sample of 167 patients with CHR syndromes and 167 with ROD was recruited from February 1, 2014, to May 31, 2017, of whom 26 (23 with CHR syndromes and 3 with ROD) developed psychosis. Patients with 18-month follow-up (n = 246) were used for model training and leave-one-site-out cross-validation. The remaining 88 patients with nontransition served as the validation of model specificity. Three hundred thirty-four healthy volunteers provided a normative sample for prognostic signature evaluation. Three independent Swiss projects contributed a further 45 cases with psychosis transition and 600 with nontransition for the external validation of clinical-neurocognitive, sMRI-based, and combined models. Data were analyzed from January 1, 2019, to March 31, 2020.

MAIN OUTCOMES AND MEASURES

Accuracy and generalizability of prognostic systems.

RESULTS

A total of 668 individuals (334 patients and 334 controls) were included in the analysis (mean [SD] age, 25.1 [5.8] years; 354 [53.0%] female and 314 [47.0%] male). Clinicians attained a balanced accuracy of 73.2% by effectively ruling out (specificity, 84.9%) but ineffectively ruling in (sensitivity, 61.5%) psychosis transition. In contrast, algorithms showed high sensitivity (76.0%-88.0%) but low specificity (53.5%-66.8%). A cybernetic risk calculator combining all algorithmic and human components predicted psychosis with a balanced accuracy of 85.5% (sensitivity, 84.6%; specificity, 86.4%). In comparison, an optimal prognostic workflow produced a balanced accuracy of 85.9% (sensitivity, 84.6%; specificity, 87.3%) at a much lower diagnostic burden by sequentially integrating clinical-neurocognitive, expert-based, PRS-based, and sMRI-based risk estimates as needed for the given patient. Findings were supported by good external validation results.

CONCLUSIONS AND RELEVANCE

These findings suggest that psychosis transition can be predicted in a broader risk spectrum by sequentially integrating algorithms' and clinicians' risk estimates. For clinical translation, the proposed workflow should undergo large-scale international validation.

Grey and white matter associations of psychotic-like experiences in a general population sample (UK Biobank)

There has been a substantial amount of research reporting the neuroanatomical associations of psychotic symptoms in people with schizophrenia. Comparatively little attention has been paid to the neuroimaging correlates of subclinical psychotic symptoms, so-called "psychotic-like experiences" (PLEs), within large healthy populations. PLEs are relatively common in the general population (7-13%), can be distressing and negatively affect health. This study therefore examined gray and white matter associations of four different PLEs (auditory or visual PLEs, and delusional ideas about conspiracies or communications) in subjects of the UK Biobank study with neuroimaging data (N = 21,390, mean age = 63 years). We tested for associations between any PLE (N = 768) and individual PLEs with gray and white matter brain structures, controlling for sex, age, intracranial volume, scanning site, and position in the scanner. Individuals that reported having experienced auditory hallucinations (N = 272) were found to have smaller volumes of the caudate, putamen, and accumbens (β = -0.115-0.134, pcorrected = 0.048-0.036), and reduced temporal lobe volume (β = -0.017, pcorrected = 0.047) compared to those that did not. People who indicated that they had ever believed in unreal conspiracies (N = 111) had a larger volume of the left amygdala (β = 0.023, pcorrected = 0.038). Individuals that reported a history of visual PLEs (N = 435) were found to have reduced white matter microstructure of the forceps major (β = -0.029, pcorrected = 0.009), an effect that was more marked in participants who reported PLEs as distressing. These associations were not accounted for by diagnoses of psychotic or depressive illness, nor the known risk factors for psychotic symptoms of childhood adversity or cannabis use. These findings suggest altered regional gray matter volumes and white matter microstructure in association with PLEs in the general population. They further suggest that these alterations may appear more frequently with the presentation of different psychotic symptoms in the absence of clinically diagnosed psychotic disorders.

Abnormal asymmetry of thalamic volume moderates stress from parents and anxiety symptoms in children and adolescents with social anxiety disorder

Social anxiety disorder (SAD) usually onsets in childhood or adolescence and is associated with brain development and chronic family stress during this period. As an information hub, the thalamus plays a crucial role in the development of emotion processing and stress regulation. Its structural and functional lateralization have been related to mental disorders. This study examined the age-dependent asymmetry of the thalamic volume in children and adolescents with SAD. We further examined the role of the thalamic asymmetry in moderating the relationships between parental alienation, which is a main source of familial stress for children and adolescents, and anxiety symptoms in this population. Fifty-three medication-free children and adolescents with SAD and 53 typical developing controls (age: 8-17) were included. Anxiety severity was measured using the Screen for Child Anxiety-Related Emotional Disorders (SCARED). We estimated the bilateral thalamic volume and examined diagnosis effect and age-group difference on the thalamic asymmetry. We further examined the moderation of the thalamic asymmetry on the associations between scores on the parental alienation, social phobia, and total SCARED. Compared with controls, the SAD group exhibited significantly abnormal asymmetry in thalamic volume. This asymmetry became more evident in the older age group. Furthermore, this asymmetry significantly weakened the relationships between parental attachment and total SCARED score. The asymmetry of the thalamic volume and its age-group difference provide novel evidence to support brain developmental abnormalities in children and adolescents with SAD. The findings further revealed interactions between physiological and chronic stress in children and adolescents with SAD. This article is part of the special issue on 'Stress, Addiction and Plasticity'.

Two distinct neuroanatomical subtypes of schizophrenia revealed using machine learning

Neurobiological heterogeneity in schizophrenia is poorly understood and confounds current analyses. We investigated neuroanatomical subtypes in a multi-institutional multi-ethnic cohort, using novel semi-supervised machine learning methods designed to discover patterns associated with disease rather than normal anatomical variation. Structural MRI and clinical measures in established schizophrenia (n = 307) and healthy controls (n = 364) were analysed across three sites of PHENOM (Psychosis Heterogeneity Evaluated via Dimensional Neuroimaging) consortium. Regional volumetric measures of grey matter, white matter, and CSF were used to identify distinct and reproducible neuroanatomical subtypes of schizophrenia. Two distinct neuroanatomical subtypes were found. Subtype 1 showed widespread lower grey matter volumes, most prominent in thalamus, nucleus accumbens, medial temporal, medial prefrontal/frontal and insular cortices. Subtype 2 showed increased volume in the basal ganglia and internal capsule, and otherwise normal brain volumes. Grey matter volume correlated negatively with illness duration in Subtype 1 (r = -0.201, P = 0.016) but not in Subtype 2 (r = -0.045, P = 0.652), potentially indicating different underlying neuropathological processes. The subtypes did not differ in age (t = -1.603, df = 305, P = 0.109), sex (chi-square = 0.013, df = 1, P = 0.910), illness duration (t = -0.167, df = 277, P = 0.868), antipsychotic dose (t = -0.439, df = 210, P = 0.521), age of illness onset (t = -1.355, df = 277, P = 0.177), positive symptoms (t = 0.249, df = 289, P = 0.803), negative symptoms (t = 0.151, df = 289, P = 0.879), or antipsychotic type (chi-square = 6.670, df = 3, P = 0.083). Subtype 1 had lower educational attainment than Subtype 2 (chi-square = 6.389, df = 2, P = 0.041). In conclusion, we discovered two distinct and highly reproducible neuroanatomical subtypes. Subtype 1 displayed widespread volume reduction correlating with illness duration, and worse premorbid functioning. Subtype 2 had normal and stable anatomy, except for larger basal ganglia and internal capsule, not explained by antipsychotic dose. These subtypes challenge the notion that brain volume loss is a general feature of schizophrenia and suggest differential aetiologies. They can facilitate strategies for clinical trial enrichment and stratification, and precision diagnostics.

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

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

Anatomic abnormalities of hippocampal subfields in never-treated and antipsychotic-treated patients with long-term schizophrenia

Hippocampal volume deficits have been reported in chronically-treated schizophrenia patients, however, the longer-term effects of antipsychotic medications on hippocampal anatomy are unclear. This case-control study investigated volume differences in hippocampal subfields of never-treated and antipsychotic-treated patients with long-term schizophrenia. High spatial-resolution T1-weighted magnetic resonance images were collected from 29 never-treated and 40 antipsychotic-treated patients with long-term schizophrenia matched for illness duration (all ≥ 5 years), and 40 demographically-matched healthy controls. Hippocampal subfield volumes were measured using FreeSurfer v6.0, compared across groups and between hemispheres, and correlated with clinical features. Volume reductions were found in both patient groups compared to healthy controls in 8 of 26 hippocampal subfields (Cohen's d = 0.46 - 1.17, P = < .001 - .03), and more diffusely and obviously in never-treated than treated patients (Cohen's d = 0.50 - 0.90, P = < .001 - .04). Greater right-than-left volumes were seen in treated patients and healthy controls in 11 of 13 subfields (T = 2.30 - 7.29, P = < .001 - .03), but not in never-treated patients, in whom the volumes were reduced more on the right than on the left. Subfield volumes were negatively correlated with symptom severity and illness duration, and declined with age in never-treated patients. Findings indicate clinically-relevant and age-related volume reductions in hippocampal subfields of never-treated patients with long-term schizophrenia. Broader and greater subfield deficits in never-treated than treated patients, especially in the right hippocampus, suggest that long-term antipsychotic treatment may benefit hippocampal structures over the longer-term course of illness.

Developmental trajectories of subcortical structures in relation to dimensional schizotypy expression along adolescence

Morphological abnormalities of subcortical structures have been consistently reported along the schizophrenia clinical spectrum, and they may play an important role in the pathophysiology of psychosis. However, the question arises whether these subcortical features are consequences of medication and illness chronicity, or if they contribute to the vulnerability to develop schizophrenia spectrum disorders. If some of the subcortical abnormalities could be evidenced in community adolescents expressing higher schizotypal traits (psychometric schizotypy), they could potentially shed light on vulnerability markers. To date, very few studies have examined the link between psychometric schizotypy and volumes of subcortical regions, and none of them have used a longitudinal design. This study sets out to investigate developmental trajectories of subcortical volumes in 110 community adolescents (12 to 20 years old), for whom MRI-scans were acquired over a period of 5 years, reaching a total of 297 scans. Analyses were conducted using Freesurfer, and schizotypal traits were measured with the Schizotypal Personality Questionnaire (SPQ). Using mixed model regression analyses following a region-of-interest approach, we observed differential linear developmental trajectories in four subcortical structures when comparing higher versus lower scorers on the disorganized schizotypy dimension (bilateral hippocampus, left-lateral ventricle and left-pallidum) and the negative schizotypy dimension (bilateral pallidum, and right-thalamus). All results survived a threshold of p < .05 (FDR-corrected) while covarying for the effect of other psychological problems (externalized and internalized psychopathology). These results indicate that expression of higher levels of negative and disorganized schizotypy during adolescence was associated with neural markers linking schizotypy personality features to schizophrenia spectrum disorders.