Using brain structural neuroimaging measures to predict psychosis onset for individuals at clinical high-risk.

Machine learning approaches using structural magnetic resonance imaging (sMRI) can be informative for disease classification, although their ability to predict psychosis is largely unknown. We created a model with individuals at CHR who developed psychosis later (CHR-PS+) from healthy controls (HCs) that can differentiate each other. We also evaluated whether we could distinguish CHR-PS+ individuals from those who did not develop psychosis later (CHR-PS-) and those with uncertain follow-up status (CHR-UNK). T1-weighted structural brain MRI scans from 1165 individuals at CHR (CHR-PS+, n = 144; CHR-PS-, n = 793; and CHR-UNK, n = 228), and 1029 HCs, were obtained from 21 sites. We used ComBat to harmonize measures of subcortical volume, cortical thickness and surface area data and corrected for non-linear effects of age and sex using a general additive model. CHR-PS+ (n = 120) and HC (n = 799) data from 20 sites served as a training dataset, which we used to build a classifier. The remaining samples were used external validation datasets to evaluate classifier performance (test, independent confirmatory, and independent group [CHR-PS- and CHR-UNK] datasets). The accuracy of the classifier on the training and independent confirmatory datasets was 85% and 73% respectively. Regional cortical surface area measures-including those from the right superior frontal, right superior temporal, and bilateral insular cortices strongly contributed to classifying CHR-PS+ from HC. CHR-PS- and CHR-UNK individuals were more likely to be classified as HC compared to CHR-PS+ (classification rate to HC: CHR-PS+, 30%; CHR-PS-, 73%; CHR-UNK, 80%). We used multisite sMRI to train a classifier to predict psychosis onset in CHR individuals, and it showed promise predicting CHR-PS+ in an independent sample. The results suggest that when considering adolescent brain development, baseline MRI scans for CHR individuals may be helpful to identify their prognosis. Future prospective studies are required about whether the classifier could be actually helpful in the clinical settings.

Psychiatric Emergencies in the Community: Characteristics and Outcome in Switzerland.

Psychiatric emergencies occur frequently in the community setting, e.g. the patient's home or public places. Little is known about the characteristics and outcome of these situations. This study describes psychiatric emergencies in the canton of Zurich, Switzerland, and examines determinants of their outcome. We retrospectively analyzed 620 medical records of consultations classified as psychiatric emergencies of a 24/7 service of community-based emergency physicians. Information on sociodemographic, clinical and situational factors was extracted. The observation period was 6 months in 2017. Binary logistic regression was used to examine predictors for involuntary admissions. Most emergency consultations (64.5%) took place at the patient's home, followed by police stations (31.0%), public places (3.2%), and somatic hospitals (1.3%). Patient characteristics and reasons for consultation varied considerably between the locations. The first involved person was commonly a relative. Of all consultations, 38.4% resulted in involuntary admissions, mainly in patients with psychosis, suicidality, aggression, refusal of necessary treatment and previous involuntary admissions. Situation-related factors and the involvement of relatives were no significant predictors of the outcome. Psychiatric emergencies occur in different places and in patients with a variety of psychiatric symptoms. Although half of the emergency situations were resolved in the community, the rate of involuntary admissions was still high. For additional reduction, the further development of quickly available alternatives to psychiatric inpatient treatment is required. These should be specifically geared towards acute situations in patients with the described risk factors. Additionally, the role of relatives during psychiatric emergencies should be further studied.

Assessing the severity of psychiatric disorders using the Health of the Nation Outcome Scales: An equipercentile linking analysis.

OBJECTIVE: The Health of the Nation Outcome Scales was developed as an overall measure of mental health, applicable to the complete range of psychiatric disorders. Meanwhile, it is a benchmark tool for service providers and is also used for the allocation of costs and funding. The ability of the Health of the Nation Outcome Scales to assess and differentiate the severity of psychiatric disorders is largely unknown, as it is the interpretation of a change in score. We aim to establish Health of the Nation Outcome Scales cut-off and benchmark values for severity and improvement - respectively change, using equipercentile linking to the Clinical Global Impression scales. METHODS: In a clinical sample of 30,616 individuals with a psychiatric disorder, we used a multivariate regression analysis to determine the correlation between the scales and possible confounders. We used an equipercentile linking analysis of the Clinical Global Impressions severity scale with the Health of the Nation Outcome Scales sum score to establish cut-off values for severity. The linking of the Health of the Nation Outcome Scales sum score difference and the percentage of change to the Clinical Global Impression improvement scale determined benchmark values for change (i.e. improvement or deterioration). RESULTS: The Health of the Nation Outcome Scales and Clinical Global Impression scales showed a Spearman correlation of 0.38 (p < 0.000). Clinical Global Impression-Severity: 'borderline-ill' corresponded to Health of the Nation Outcome Scales score 3-5; 'mildly ill' to 6-10; 'moderately ill' to 11-16; 'markedly ill' to 17-25; 'severely ill' to 26-35; and 'extremely ill' to a score ⩾36. The Spearman correlation between the percentage change of the Health of the Nation Outcome Scales was 0.39 (p > 0.000); Clinical Global Impression-Improvement: 'minimally improved' corresponded to Health of the Nation Outcome Scales reduction of 4 points or 9%; 'much-improved' to 12 points or 48%; 'very-much-improved' to ⩾20 points or ⩾90%. Clinical Global Impression-Improvement: 'minimally worse' corresponded to an increase of 6 points or 25%; 'much-worse' to 12 points or 54%; and finally, 'very-much-worse' to >18 points or ⩾82%. CONCLUSION: Our results allow for the comparison of severity and response to treatment of patients with a psychiatric disorder, independent of diagnosis.

[The role of psychopathology and nosology in 'precision' psychiatry]. / Die Rolle von Psychopathologie und Nosologie in der 'Precision'-Psychiatrie.

Psychopathology is the scientific exploration of abnormal mental experiences and behaviour that, for more than a century, has provided a Gestalt for psychiatric disorders and, thereby, the basis of psychiatric nosology. Having guided clinical and scientific progress in modern psychiatry, in consequence of considerable technical progress, psychopathology has been increasingly marginalised by neurobiological research. Albeit the precise, careful and qualified assessment of psychopathology has been a core skill of mental health professionals, today's curricula pay increasingly less attention to its training. However, because neurobiological models still have to prove their diagnostic superiority and despite all prophecies that psychopathology was doomed, psychiatric diagnoses in both DSM-5 and ICD-11 continue to rely exclusively on psychopathology. Their categorical nosology is also challenged by advances in computational psychiatry and an increasingly advocated personalised symptom-based approach to precision psychiatry. The current paper reviews the objectives of psychopathology and nosology, and the recent debate on their role in future precision psychiatry - from guiding neurobiological research by relating neurobiological changes to patients' experiences to giving a framework to the psychiatric encounter. It concludes that contemporary psychiatry does not need less but rather a more differentiated psychopathology and a likely reformed, possibly more dimensional nosology in order to develop approaches that adequately integrate patients' experiences and professional knowledge.

Rare copy number variants in individuals at clinical high risk for psychosis: Enrichment of synaptic/brain-related functional pathways.

Schizophrenia is a complex and chronic neuropsychiatric disorder, with a heritability of around 60-80%. Large (>100 kb) rare (<1%) copy number variants (CNVs) occur more frequently in schizophrenia patients compared to controls. Currently, there are no studies reporting genome-wide CNVs in clinical high risk for psychosis (CHR-P) individuals. The aim of this study was to investigate the role of rare genome-wide CNVs in 84 CHR-P individuals and 124 presumably healthy controls. There were no significant differences in all rare CNV frequencies and sizes between CHR-P individuals and controls. However, brain-related CNVs and brain-related deletions were significantly more frequent in CHR-P individuals than controls. In CHR-P individuals, significant associations were found between brain-related CNV carriers and attenuated positive symptoms syndrome or cognitive disturbances (OR = 3.07, p = .0286). Brain-related CNV carriers experienced significantly higher negative symptoms (p = .0047), higher depressive symptoms (p = .0175), and higher disturbances of self and surroundings (p = .0029) than noncarriers. Furthermore, enrichment analysis of genes was performed in the regions of rare CNVs using three independent methods, which confirmed significant clustering of predefined genes involved in synaptic/brain-related functional pathways in CHR-P individuals. These results suggest that rare CNVs might affect synaptic/brain-related functional pathways in CHR-P individuals.

Knowledge on types of treatment pressure. A cross-sectional study among mental health professionals.

Treatment pressure restricts patients' voluntary and autonomous decisions. Yet interventions involving treatment pressure are widely used in mental health and psychosocial services. This cross-sectional study explored whether mental health professionals' knowledge on five types of treatment pressure (no coercion, persuasion or conviction, leverage, threat, and formal coercion) was associated with sociodemographic, professional and contextual factors. A more positive attitude towards interventions involving treatment pressure was associated with underrating the level of those interventions compared with a predefined default value. The treatment setting and professional group played a minor role in 'leverage' and 'formal coercion' types of treatment pressure, respectively.

[Early detection of psychosis: evidence and perspectives]. / Früherkennung von Psychosen: Evidenz und Perspektiven.

Early detection of psychosis: evidence and perspectives Abstract. Early detection of psychosis, in the sense of preventing psychosis, has become increasingly important in recent years. Especially psychopathological approaches are promising and are reflected in the attenuated and transient positive symptoms ("ultra high risk" criteria) and the basic symptom criterion "cognitive disturbances". According to the recommendation of the European Psychiatric Association (EPA), both risk-criteria sets are currently the most well-tested diagnostic criteria for a psychosis risk syndrome. Moreover, comorbid mental disorders and psychosocial problems are frequently the reasons for treatment.

Self-labelling and stigma as predictors of attitudes towards help-seeking among people at risk of psychosis: 1-year follow-up.

Mental health service use is helpful but rare among young people at risk of psychosis. The label and stigma associated with mental illness may affect attitudes towards help-seeking. We examined 67 individuals at risk of psychosis over the course of 1 year. An increase of self-labelling as "mentally ill" predicted more positive attitudes towards psychiatric medication, while increased perceived stigma and the cognitive appraisal of stigma as a stressor predicted poorer attitudes towards psychotherapy after 1 year. Early intervention could improve non-stigmatizing awareness of at-risk mental state and reduce the public stigma associated with at-risk status to facilitate help-seeking.

Quality criteria of involuntary psychiatric admissions - before and after the revision of the civil code in Switzerland.

BACKGROUND: The goal was to investigate the quality in terms of formal and content-based comprehensiveness of the forms for involuntary admission before and after the introduction of the new law (KESR, "Kindes- und Erwachsenenschutzrecht") for the regulation of involuntary admission. Moreover, the study aimed at assessing if the quality of the admission forms was associated with the professional qualifications of the professionals ordering them. Finally, the patients were characterized. METHODS: Retrospective evaluation of all commitment reports at the University Hospital of Psychiatry within a six month period before and after the introduction the KESR (N(2012) = 489; N(2013) = 651). Formal and content-related criteria for the commitment certificates were recorded as well as the socio-demographic and clinical data of the cases admitted. There were no exclusion criteria. The data was descriptively evaluated, formal and content-based criteria were compared between groups of admitting professionals. The Chi-Square-Test following Pearson and T-Test were used to test for group differences. RESULTS: Formal and content-related quality criteria deficiencies were noted. The best-documented forms came from psychiatrists and emergency physicians, followed by general practitioners and hospital doctors. There have been improvements in the quality of the documents since the new KESR within all professional subsamples. CONCLUSIONS: Psychiatrists and those who regularly deal with emergency commitments were likely to issue forms of high quality. Due to the considerable consequences associated with involuntary admission for affected individuals, their relatives and also professionals, the considerable deficits in the quality of the documentation must be intensively addressed in training, advanced training, continuing education and in daily routines.

Evaluation of a new person-centered integrated care model in psychiatry.

The present study evaluated a new integrated treatment concept offering inpatient care, acute psychiatric day hospital and outpatient treatment by the same therapeutic team. 178 patients participated in this randomized controlled trial. Data on psychopathology, global and social functioning, patient satisfaction, continuity of care and administrative data was gathered on admission, throughout the course of treatment, upon discharge and at 1-year follow-up. In addition, the physicians in charge rated the therapeutic relationship. The data analysis consists of group-wise comparisons and regression analyses (cross-tabulations and χ(2) test statistics for categorical data and Mann-Whitney U tests for continuous data). Differences between groups over time were analyzed with a series of generalized linear mixed model. The integrated care group showed a significant reduction in psychopathological impairment (20.7%) and an improvement of psychosocial functioning (36.8%). The mean number of days before re-admission was higher in the control group when compared to the integrated care group (156.8 vs. 91.5). There was no difference in the number of re-admissions and days spent in psychiatric institutions. This new approach offers a treatment model, which facilitates continuity of care. Beside it improves psychopathological outcome measures and psychosocial functioning in patients with mental illness.

[Cantonal Differences in The Implementation of Involuntary Admission in Switzerland]. / Kantonale Unterschiede bei der Umsetzung der fürsorgerischen Unterbringung in der Schweiz.

OBJECTIVE: To examine sociodemographic and clinical characteristics of persons hospitalized in five psychiatric hospitals from regions with different structural characteristics compared with persons hospitalized voluntarily. METHODS: Descriptive analyses of routine data on approximately 57000 cases of 33000 patients treated for a primary ICD-10 psychiatric diagnosis at one of the participating hospitals from 2016 to 2019. RESULTS: Admission rates, length of stay, rates of further coercive measures, sociodemographic and clinical characteristics of the affected persons differ between the different regions. CONCLUSION: There are considerable regional differences between regulations and implementation of the admission procedures and the sample. Causal relationships between regional specifics and the results cannot be inferred.

Predicting coercion during the course of psychiatric hospitalizations.

BACKGROUND: Coercive measures (such as seclusion, mechanical restraint, and forced medication) during psychiatric inpatient treatment should be avoided whenever possible. Different interventions were already developed to reduce coercion, but for their effective application, it is crucial to know the risk factors of individuals and clinical situations that might be associated with coercion. Since the results of previous studies differ considerably the current study aims to fill this gap by evaluating the course of the exertion of coercion in detail. METHODS: In this study, we analyzed clinical, procedural, and sociodemographic data from patients (n = 16,607 cases) who were treated as inpatients in Switzerland's largest psychiatric institution with 320 beds during the years 2017 to 2020. We used regression models to identify predictors for the exertion of coercion, the number of coercive measures during a treatment episode and time until exertion of the first and last coercive measure. RESULTS: Coercive measures are mostly used during the first days of treatment. We identified clinical parameters such as manic or psychotic episodes to be the most relevant predictors for the exertion of coercion. Cases with those disorders also received coercion more often and earlier in their treatment course than other diagnostic groups. Other promoting factors for frequency and early application of coercion were involuntary admission and factors of chronicity and clinical severity. CONCLUSIONS: Knowing the risk factors may help to target preventive strategies for those at highest risk. In particular, interventions should focus on the critical timeframe at the beginning of treatment.

Association between perceived coercion and perceived level of information in involuntarily admitted patients: Results from a multicenter observational study in Switzerland.

BACKGROUND: Involuntary admissions (IA) to psychiatric hospitals are controversial because they interfere with people's autonomy. In some situations, however, they appear to be unavoidable. Interestingly, not all patients perceive the same degree of coercion during IA. The aim of this study was to assess whether the level of knowledge about one's own IA is associated with perceived coercion. METHODS: This multicenter observational study was conducted on n = 224 involuntarily admitted patients. Interviews were conducted at five study centers from April 2021 to November 2021. The Macarthur Admission Experience Survey was administered to assess perceived coercion. Knowledge of involuntary admission, perceptions of information received, and attitudes towards legal aspects of involuntary admission were also assessed. RESULTS: We found that higher levels of knowledge about IA were negatively associated with perceived coercion at admission. Perceived coercion did not differ between study sites. Only half of the patients felt well informed about their IA, and about a quarter found the information they received difficult to understand. DISCUSSION: Legislation in Switzerland requires that patients with IA be informed about the procedure. Strategies to improve patients' understanding of the information given to them about IA might be helpful to reduce perceived coercion, which is known to be associated with negative attitudes towards psychiatry, a disturbed therapeutic relationship, avoidance of psychiatry, and the risk of further coercion.

Mismatch negativity generation in subjects at risk for psychosis: source analysis is more sensitive than surface electrodes in risk prediction.

Background: Deficits of mismatch negativity (MMN) in patients with schizophrenia have been demonstrated many times and there is growing evidence that alterations of MMN already exist in individuals at risk for psychosis. The present study examines differences in MMN between subjects fulfilling ultra-high risk (UHR) or only basic symptoms criteria and it addresses the question, if MMN source analysis can improve prediction of transition to psychosis. Methods: The MMN to duration, frequency, and intensity deviants was recorded in 50 healthy controls and 161 individuals at risk for psychosis classified into three subgroups: only basic symptoms (n = 74), only ultra-high risk (n = 13) and persons who fulfill both risk criteria (n = 74). Based on a three-source model of MMN generation, we conducted an MMN source analysis and compared the amplitudes of surface electrodes and sources among the three groups. Results: Significant differences in MMN generation among the four groups were revealed at surface electrodes Cz and C4 (p < 0.05) and at the frontal source (p < 0.001) for duration deviant stimuli. The 15 subjects from the risk groups who subsequently developed a manifest psychosis had a significantly lower MMN amplitude at frontal source (p = 0.019) without showing significant differences at surface electrodes. Low activity at frontal MMN source increased the risk of transition to manifest disease by the factor 3.12 in UHR subjects. Conclusion: MMN activity differed significantly between subjects presenting only basic symptoms and subjects which additionally meet UHR criteria. The largest differences between groups as well as between individuals with and without transition were observed at the frontal source. The present results suggest that source analysis is more sensitive than surface electrodes in psychosis risk prediction by MMN.

Gender and rapid alterations of hemispheric dominance during planning.

BACKGROUND: Mental planning and carrying out a plan provoke specific cerebral hemodynamic responses. Gender aspects of hemispheric laterality using rapid cerebral hemodynamics have not been reported. METHOD: Here, we applied functional transcranial Doppler sonography to examine lateralization of cerebral hemodynamics of the middle cerebral arteries of 28 subjects (14 women and 14 men) performing a standard planning task. There were easy and difficult problems, and mental planning without motor activity was separated from movement execution. RESULTS: Difficult mental planning elicited lateralization to the right hemisphere after 2 or more seconds, a feature that was not observed during movement execution. In females, there was a dominance to the left hemisphere during movement execution. Optimized problem solving yielded an increased laterality change to the right during mental planning. CONCLUSIONS: Gender-related hemispheric dominance appears to be condition-dependent, and change of laterality to the right may play a role in optimized performance. Results are of relevance when considering laterality from a perspective of performance enhancement of higher cognitive functions, and also of psychiatric disorders with cognitive dysfunctions and abnormal lateralization patterns such as schizophrenia.

White matter microstructure and the clinical risk for psychosis: A diffusion tensor imaging study of individuals with basic symptoms and at ultra-high risk.

BACKGROUND: Widespread white matter abnormalities are a frequent finding in chronic schizophrenia patients. More inconsistent results have been provided by the sparser literature on at-risk states for psychosis, i.e., emerging subclinical symptoms. However, considering risk as a homogenous construct, an approach of earlier studies, may impede our understanding of neuro-progression into psychosis. METHODS: An analysis was conducted of 3-Tesla MRI diffusion and symptom data from 112 individuals (mean age, 21.97 ± 4.19) within two at-risk paradigm subtypes, only basic symptoms (n = 43) and ultra-high risk (n = 37), and controls (n = 32). Between-group comparisons (involving three study groups and further split based on the subsequent transition to schizophrenia) of four diffusion-tensor-imaging-derived scalars were performed using voxelwise tract-based spatial statistics, followed by correlational analyses with Structured Interview for Prodromal Syndromes responses. RESULTS: Relative to controls, fractional anisotropy was lower in the splenium of the corpus callosum of ultra-high-risk individuals, but only before stringent multiple-testing correction, and negatively correlated with General Symptom severity among at-risk individuals. At-risk participants who transitioned to schizophrenia within 3 years, compared to those that did not transition, had more severe WM differences in fractional anisotropy and radial diffusivity (particularly in the corpus callosum, anterior corona radiata, and motor/sensory tracts), which were even more extensive compared to healthy controls. CONCLUSIONS: These findings align with the subclinical symptom presentation and more extensive disruptions in converters, suggestive of severity-related demyelination or axonal pathology. Fine-grained but detectable differences among ultra-high-risk subjects (i.e., with brief limited intermittent and/or attenuated psychotic symptoms) point to the splenium as a discrete site of emerging psychopathology, while basic symptoms alone were not associated with altered fractional anisotropy.

Psychometric evaluation of the German version of the Opening Minds Stigma Scale for Health Care Providers (OMS-HC).

BACKGROUND: Healthcare professionals can be a source of stigma and discrimination for people with mental illness, and anti-stigma programs are needed for this target group. However, there is no validated German language scale to assess attitudes of healthcare professionals towards people with mental illness. This study had the aim to validate the German language version of the Opening Minds Stigma Scale for Health Care Providers (OMS-HC), a self-report measure of stigmatizing attitudes. METHODS: Staff (n = 392) on general psychiatric inpatient wards (excluding child, forensic and geriatric psychiatry) at five psychiatric hospitals in Switzerland (n = 3) and Germany (n = 2) participated in the study. The internal consistency of the OMS-HC was examined as well as its factor structure using exploratory and confirmatory factor analyses. To assess the scale's concurrent validity, we used the Social Distance Scale. RESULTS: Internal consistency for the OMS-HC total score was good (α = 0.74), acceptable for the subscales Attitudes (α = 0.62) and Social Distance (α = 0.69), and poor for the Disclosure subscale (α = 0.55). The original three-factor structure fit our data well. The OMS-HC total score and the Social Distance subscale score were significantly correlated with the Social Distance Scale, supporting concurrent validity. CONCLUSION: The German version of the OMS-HC demonstrated satisfactory psychometric properties and can be recommended for future research and intervention evaluation.

Polygenic risk scores across the extended psychosis spectrum.

As early detection of symptoms in the subclinical to clinical psychosis spectrum may improve health outcomes, knowing the probabilistic susceptibility of developing a disorder could guide mitigation measures and clinical intervention. In this context, polygenic risk scores (PRSs) quantifying the additive effects of multiple common genetic variants hold the potential to predict complex diseases and index severity gradients. PRSs for schizophrenia (SZ) and bipolar disorder (BD) were computed using Bayesian regression and continuous shrinkage priors based on the latest SZ and BD genome-wide association studies (Psychiatric Genomics Consortium, third release). Eight well-phenotyped groups (n = 1580; 56% males) were assessed: control (n = 305), lower (n = 117) and higher (n = 113) schizotypy (both groups of healthy individuals), at-risk for psychosis (n = 120), BD type-I (n = 359), BD type-II (n = 96), schizoaffective disorder (n = 86), and SZ groups (n = 384). PRS differences were investigated for binary traits and the quantitative Positive and Negative Syndrome Scale. Both BD-PRS and SZ-PRS significantly differentiated controls from at-risk and clinical groups (Nagelkerke's pseudo-R2: 1.3-7.7%), except for BD type-II for SZ-PRS. Out of 28 pairwise comparisons for SZ-PRS and BD-PRS, 9 and 12, respectively, reached the Bonferroni-corrected significance. BD-PRS differed between control and at-risk groups, but not between at-risk and BD type-I groups. There was no difference between controls and schizotypy. SZ-PRSs, but not BD-PRSs, were positively associated with transdiagnostic symptomology. Overall, PRSs support the continuum model across the psychosis spectrum at the genomic level with possible irregularities for schizotypy. The at-risk state demands heightened clinical attention and research addressing symptom course specifiers. Continued efforts are needed to refine the diagnostic and prognostic accuracy of PRSs in mental healthcare.

[Assessment of overinclusion in schizophrenia by a computer-assisted version of the Concept Overinclusion test]. / Erfassung des veränderten Begriffsumfangs bei Schizophrenie mit Hilfe der computergestützten Version des Begriffsumfangstests (BUT).

OBJECTIVE: A special form of formal thought disorder is the overinclusion in schizophrenia. The Begriffsumfangstest (BUT, Concept Overinclusion test) is a neuropsychological test for the assessment of this phenomenon. The test is available in a paperand- pencil version since the 1990s and now available in a computerized version. The aim of this study was a replication of the paper-and-pencil version with the computerized version of the test and also the detection of putative correlations with ego-psychopathology. METHODS: 40 patients with schizophrenia and 16 healthy controls were assessed with the BUT and with a scale for the assessment of ego-psychopathology (IPP). The tests were performed on five different time points with intervals of approximately two weeks. RESULTS: The BUT-parameters for the group of patients and the control group differed significantly. Several positive correlations were found between he values of the BUT and the IPP. CONCLUSION: The computerized Version of the BUT is also applicable for the detection of overinclusion. The relation between overinclusion as a semantic dysfunction and ego-psychopathology may lead to further psychopathological investigations concerning schizophrenic thought disorders.

Cortical Volume Differences in Subjects at Risk for Psychosis Are Driven by Surface Area.

In subjects at risk for psychosis, the studies on gray matter volume (GMV) predominantly reported volume loss compared with healthy controls (CON). However, other important morphological measurements such as cortical surface area (CSA) and cortical thickness (CT) were not systematically compared. So far, samples mostly comprised subjects at genetic risk or at clinical risk fulfilling an ultra-high risk (UHR) criterion. No studies comparing UHR subjects with at-risk subjects showing only basic symptoms (BS) investigated the differences in CSA or CT. Therefore, we aimed to unravel the contribution of the 2 morphometrical measures constituting the cortical volume (CV) and to test whether these groups inhere different morphometric features. We conducted a surface-based morphometric analysis in 34 CON, 46 BS, and 39 UHR to examine between-group differences in CV, CSA, and CT vertex-wise across the whole cortex. Compared with BS and CON, UHR individuals presented increased CV in frontal and parietal regions, which was driven by larger CSA. These groups did not differ in CT. Yet, at-risk subjects who later developed schizophrenia showed thinning in the occipital cortex. Furthermore, BS presented increased CSA compared with CON. Our results suggest that volumetric differences in UHR subjects are driven by CSA while CV loss in converters seems to be based on cortical thinning. We attribute the larger CSA in UHR to aberrant pruning representing a vulnerability to develop psychotic symptoms reflected in different levels of vulnerability for BS and UHR, and cortical thinning to a presumably stress-related cortical decomposition.