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Objective: To create a new taxonomy of schizophrenia spectrum disorders (SSD) based on the comparability of the design of SSD and borderline states., Material and Methods: The total sample consists of 205 patients with an established diagnosis of SSD (F21; F25; F22 according to ICD-10) collected from studies of the department of borderline mental pathology and psychosomatic disorders of the Federal State Budgetary Institution Mental Health Research Center and the Department of Psychiatry and Psychosomatics of Moscow State Medical University in the period 2014 to 2024. Clinical, psychometric, statistical methods were used., Results: A new two-level model of schizotypal personality disorder (STPD) has been developed: the first level is psychopathic-like disorders of the «Ferschroben» type; the second level are psychopathological disorders (positive, negative, etc.), appearing under their «mask», constituting a «tracing paper» of manifestations of schizophrenia «in miniature». The two-level psychopathological model of STPD is a complex clinical phenotype, including independent but overlapping phenotypic formations: psychopathic-like - the «Ferschroben» type; and basic - schizophreniform disorders., Conclusion: The clinical classification of schizophrenia spectrum disorders has been developed; pseudoneuroses and stress-induced disorders of the endogenous circle are considered in the aspect of the dynamics of STPD.

Schizophrenia is among the most debilitating neuropsychiatric disorders. However, clear neurophysiological markers that would identify at-risk individuals represent still an unknown. The aim of this study was to investigate possible alterations in the resting alpha oscillatory activity in normal population high on schizotypy trait, a physiological condition known to be severely altered in patients with schizophrenia. Direct comparison of resting-state EEG oscillatory activity between Low and High Schizotypy Group (LSG and HSG) has revealed a clear right hemisphere alteration in alpha activity of the HSG. Specifically, HSG shows a significant slowing down of right hemisphere posterior alpha frequency and an altered distribution of its amplitude, with a tendency towards a reduction in the right hemisphere in comparison to LSG. Furthermore, altered and reduced connectivity in the right fronto-parietal network within the alpha range was found in the HSG. Crucially, a trained pattern classifier based on these indices of alpha activity was able to successfully differentiate HSG from LSG on tested participants further confirming the specific importance of right hemispheric alpha activity and intrahemispheric functional connectivity. By combining alpha activity and connectivity measures with a machine learning predictive model optimized in a nested stratified cross-validation loop, current research offers a promising clinical tool able to identify individuals at-risk of developing psychosis (i.e., high schizotypy individuals).

We have previously argued that the current borderline personality disorder (BPD) diagnosis is over-inclusive and clinically and conceptually impossible to distinguish from the schizophrenia spectrum disorders. This study involves 30 patients clinically diagnosed with BPD as their main diagnosis by three BPD dedicated outpatient treatment facilities in Denmark. The patients underwent a careful and time-consuming psychiatric evaluation involving several senior level clinical psychiatrists and researchers and a comprehensive battery of psychopathological scales. The study found that the vast majority of patients (67% in DSM-5 and 77% in ICD-10) in fact met the criteria for a schizophrenia spectrum disorder, i.e., schizophrenia (20%) or schizotypal (personality) disorder (SPD). The schizophrenia spectrum group scored significantly higher on the level of disorders of core self as measured by the Examination of Anomalous Self-Experiences Scale (EASE). The BPD criterion of "identity disturbance" was significantly correlated with the mean total score of EASE. These findings are discussed in the light of changes from prototypical to polythetic diagnostic systems. We argue that the original prototypes/gestalts informing the creation of BPD and SPD have gone into oblivion during the evolution of polythetic criteria.

Objective: To obtain more precise and rich information from the measurements for schizotypal personality disorder (SPD), a cutting-edge psychometric theory called diagnostic classification models (DCMs) was first employed in the present study to develop a diagnostic classification version of the Schizotypal Personality Questionnaire (DC-SPQ) based on the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders., Methods: Under the framework of DCMs, 980 college students were recruited to calibrate item parameters of the Schizotypal Personality Questionnaire. Items that fit the psychometric characteristic would be selected to compose the DC-SPQ, prior to an analysis of its indexes., Results: Results showed that the DC-SPQ had high reliability and validity in both the classical test theory and DCMs, in addition to showing a sensitivity of 0.921 and a specificity of 0.841 with area under receiver operating characteristic curve = 0.936. Meanwhile, the four-factor model proposed adequately fits with the data. More importantly, the DC-SPQ provides not only the general-level information similar to traditional questionnaires but also the symptom-level information with the posterior probability, which provides an insight into delivering the individual-specific intervention that is tailor made to schizotypal personality disorder., Conclusions: This study demonstrates that the DC-SPQ is very valuable for psychometric detection in that it can clarify the symptom being measured and provide more reasonable estimates., (© 2019 The Authors. International Journal of Methods in Psychiatric Research published by John Wiley & Sons Ltd.)

The present study aimed to explore the relationship between autistic and schizotypal traits in the non-clinical population. We first conducted a meta-analysis to quantify the correlation between self-reported autistic traits and the three dimensions of schizotypal traits (positive, negative and disorganization). The strongest correlation was found between autistic traits and negative schizotypal traits (r = 0.536, 95% CI [0.481, 0.586]), followed by the disorganization (r = 0.355, 95% CI [0.304, 0.404]) and positive (r = 0.256, 95% CI [0.208, 0.302]) dimensions. To visualize the partial correlations between dimensional behavioural traits, we constructed a network model based on a large sample of college students (N = 2469). Negative schizotypal traits were strongly correlated with autistic social/communicative deficits, whereas positive schizotypal traits were inversely correlated with autistic-like traits, lending support to the psychosis-autism diametrical model. Disentangling the overlapping and diametrical structure of autism and schizophrenia may help to elucidate the aetiology of these two neurodevelopmental disorders., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Schizotypy, a multidimensional personality organization that reflects liability to develop schizophrenia-spectrum disorders, has been associated with a number of emotional abnormalities. Yet, the exact nature of any emotional abnormalities in schizotypy is relatively unclear. Using an ethnically diverse nonclinical sample (N = 2637), the present study identified homogenous clusters of individuals based on positive and negative schizotypy dimensions and explored three interrelated domains of emotion traits closely tied to functional outcomes and quality of life: affective experience, emotional awareness, and meta-level emotions. Consistent with prior research, four schizotypy clusters were obtained: low ("nonschizotypic"), high positive, high negative, and mixed (high positive and high negative). Regarding emotion correlates of schizotypy clusters, the mixed cluster was found to be the most deviant on almost all emotion traits (e.g., heightened trait negative affect, diminished emotional clarity), suggesting that the effects of positive and negative schizotypy are additive. In addition, positive and negative schizotypy clusters were associated with differential abnormalities, with the negative cluster presenting a wider range of, and more severe, impairments compared to the low cluster (e.g., reduced trait positive affect and reduced attention to positive emotion). The current study highlights the heterogeneity in emotional traits among schizotypy dimensions and the importance of studying the mixed schizotypy in terms of emotional dysfunction., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Elucidating schizotypal traits is important if we are to understand the various manifestations of psychosis spectrum liability and to reliably identify individuals at high risk for psychosis. The present study examined the network structures of (1) 9 schizotypal personality domains and (2) 74 individual schizotypal items, and (3) explored whether networks differed across gender and culture (North America vs China). The study was conducted in a sample of 27001 participants from 12 countries and 21 sites (M age = 22.12; SD = 6.28; 37.5% males). The Schizotypal Personality Questionnaire (SPQ) was used to assess 74 self-report items aggregated in 9 domains. We used network models to estimate conditional dependence relations among variables. In the domain-level network, schizotypal traits were strongly interconnected. Predictability (explained variance of each node) ranged from 31% (odd/magical beliefs) to 55% (constricted affect), with a mean of 43.7%. In the item-level network, variables showed relations both within and across domains, although within-domain associations were generally stronger. The average predictability of SPQ items was 27.8%. The network structures of men and women were similar (r = .74), node centrality was similar across networks (r = .90), as was connectivity (195.59 and 199.70, respectively). North American and Chinese participants networks showed lower similarity in terms of structure (r = 0.44), node centrality (r = 0.56), and connectivity (180.35 and 153.97, respectively). In sum, the present article points to the value of conceptualizing schizotypal personality as a complex system of interacting cognitive, emotional, and affective characteristics.

Functional magnetic resonance imaging is capable of estimating functional activation and connectivity in the human brain, and lately there has been increased interest in the use of these functional modalities combined with machine learning for identification of psychiatric traits. While these methods bear great potential for early diagnosis and better understanding of disease processes, there are wide ranges of processing choices and pitfalls that may severely hamper interpretation and generalization performance unless carefully considered. In this perspective article, we aim to motivate the use of machine learning schizotypy research. To this end, we describe common data processing steps while commenting on best practices and procedures. First, we introduce the important role of schizotypy to motivate the importance of reliable classification, and summarize existing machine learning literature on schizotypy. Then, we describe procedures for extraction of features based on fMRI data, including statistical parametric mapping, parcellation, complex network analysis, and decomposition methods, as well as classification with a special focus on support vector classification and deep learning. We provide more detailed descriptions and software as supplementary material. Finally, we present current challenges in machine learning for classification of schizotypy and comment on future trends and perspectives.

The latent structure of schizotypy and psychosis-spectrum symptoms remains poorly understood. Furthermore, molecular genetic substrates are poorly defined, largely due to the substantial resources required to collect rich phenotypic data across diverse populations. Sample sizes of phenotypic studies are often insufficient for advanced structural equation modeling approaches. In the last 50 years, efforts in both psychiatry and psychological science have moved toward (1) a dimensional model of psychopathology (eg, the current Hierarchical Taxonomy of Psychopathology [HiTOP] initiative), (2) an integration of methods and measures across traits and units of analysis (eg, the RDoC initiative), and (3) powerful, impactful study designs maximizing sample size to detect subtle genomic variation relating to complex traits (the Psychiatric Genomics Consortium [PGC]). These movements are important to the future study of the psychosis spectrum, and to resolving heterogeneity with respect to instrument and population. The International Consortium of Schizotypy Research is composed of over 40 laboratories in 12 countries, and to date, members have compiled a body of schizotypy- and psychosis-related phenotype data from more than 30000 individuals. It has become apparent that compiling data into a protected, relational database and crowdsourcing analytic and data science expertise will result in significant enhancement of current research on the structure and biological substrates of the psychosis spectrum. The authors present a data-sharing infrastructure similar to that of the PGC, and a resource-sharing infrastructure similar to that of HiTOP. This report details the rationale and benefits of the phenotypic data collective and presents an open invitation for participation.

Numerous factor analytic studies of the Schizotypal Personality Questionnaire have supported a range of solutions, many with differing numbers of factors. Although some solutions have received more support than others, it remains unclear how clinicians and researchers may evaluate solutions with similar levels of empirical support in relation to one another, and few item-level analyses have been conducted. In the current study, we seek to explore the relationships among various factor solutions in a hierarchical manner using Goldberg's (2006) Bass-Ackward approach. A final sample of 847 undergraduate students completed the Schizotypal Personality Questionnaire with a Likert-style response format. Item-level exploratory factor analyses with between one and nine factors were extracted. Interrelationships among these solutions were examined. Each solution was evaluated in terms of its content, statistical significance, simple structure, and consistency with previous findings. Factor solutions at several levels were found to replicate findings from past factor analyses in terms of individual factor content and relative merit. Solutions with between four and six factors received the most support and solutions with up to seven factors were found to achieve support. (PsycINFO Database Record, ((c) 2018 APA, all rights reserved).)

Background: Traditionally, research in the ultra-high risk (UHR) for psychosis population has focused on the treatment of existing symptomatology and prevention of transition to psychosis. Recently, there has been an increase in focus on outcomes in individuals who do not transition to psychosis. However, there is a lack of standardised definitions of remission, recovery, recurrence and relapse in UHR, resulting in the inability to generalise and replicate outcomes., Method: The aims of the current study were to develop definitions for remission, recovery, recurrence and relapse, and apply them to a UHR cohort allowing the identification of longitudinal clinical trajectories. Further stratification in broader categories of favourable and unfavourable outcomes was applied. The predictive value of various baseline factors on specific clinical trajectories was also assessed., Results: 17 different trajectories were identified in a cohort of 202 individuals within a 12-month period and classified according to the suggested definitions for recovery (35.7%), remission (7.5%), any recurrence (20%), no remission (17.3%), relapse (4.0%) and transition to psychosis (15.8%). Favourable and unfavourable trajectories represented 43.2% and 57.1% respectively. Long duration of untreated symptoms and high depression scores were associated with unfavourable outcomes., Discussion: It is possible to apply clear definitions of remission, recovery, recurrence, relapse and transition to psychosis to a UHR cohort to evaluate longitudinal clinical trajectories. Acceptance and use of these definitions will help to facilitate comparisons between trials and to improve clinical clarity across the range of available therapeutic options in UHR individuals., (Copyright © 2018 Elsevier B.V. All rights reserved.)

If schizotypy is a taxonic liability for schizophrenia with a general population prevalence of ~10%, it should also be taxonic among biological siblings of probands with schizophrenia. Moreover, assuming this is so, siblings' schizotypy class membership should be predicted by probands' familial load for psychotic disorder and clinical severity, consistent with a multifactorial polygenic threshold model of schizophrenia. We tested these hypotheses in the Genetic Risk and Outcome of Psychosis (GROUP) Study where siblings of probands (n = 792) and unaffected controls (n = 559) provided self-report ratings on the Community Assessment of Psychic Experiences (CAPE). Maximum covariance analyses of control group ratings led to the identification of CAPE items sensitive to nonredundant positive and negative schizotypy classes in the control group (prevalence = 7.9% and 11.1%, respectively). When the same taxonic solution was applied to siblings' CAPE rating, taxometric analyses yielded evidence for larger positive and negative schizotypy classes among siblings (prevalence = 14.1% and 21.8%, respectively). Whereas probands' familial loads for bipolar disorder or drug use disorders did not predict siblings' membership in the schizotypy classes, probands' familial load for psychotic disorder did. Siblings were more likely to be members of the positive schizotypy class where their probands were more severely affected. The pattern of findings is consistent with Meehl's argument that schizotypy reflects liability for schizophrenia.

The subtype system for categorising presentations of schizophrenia will be removed from International Classification of Diseases 11th Revision. In its place will be a system for rating six domains of psychotic disorder pathology: positive symptoms, negative symptoms, depressive symptoms, manic symptoms, psychomotor symptoms and cognitive symptoms. This paper outlines the rationale and description of the proposed symptom rating scale, including current controversies. In particular, the scale could adopt either a 4-point severity rating or a 2-point presence/absence rating. The 4-point scale has the advantage of gathering more information, but potentially at the cost of reliability. The paper concludes by describing the field testing process for evaluating the proposed scale.

Objective: The aim of the study was to compare the neurocognitive profile of unaffected first-degree relatives of schizophrenia patients with control individuals, controlling for different schizotypal traits., Method: One hundred and fifteen adult unaffected first-degree relatives of schizophrenia-spectrum patients and 122 controls were tested for schizotypy with the Schizotypal Personality Questionnaire. They also underwent a thorough neurocognitive assessment with a range of tasks covering several aspects of executive functioning. Between-group differences in cognition were examined first with multivariate analysis of variance and then with a series of multivariate analyses of covariance, including the schizotypal dimensions as covariates., Results: The relatives had higher scores on all schizotypal dimensions compared with controls and poorer planning, problem solving, strategy formation and working memory, irrespective of schizotypal traits. They also scored lower in executive working memory and verbal fluency. The difference in executive working memory was sensitive to the effects of paranoid and negative schizotypy (both dimensions abolished the between-group difference) whereas the difference in verbal fluency was sensitive only to the effects of paranoid schizotypy. Neither cognitive-perceptual nor disorganized schizotypy accounted for any differences in neurocognition between relatives and the controls., Conclusions: Impairments in planning, problem solving, strategy formation and working memory are "core" impairments in the schizophrenia-spectrum, possibly due to high heritability effects in these functions. Impairments in executive working memory and verbal fluency are associated with paranoid and negative schizotypy, possibly due to alterations in a common fronto-temporo-parietal neural network., (© The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

From a perspective of conceptual evolution schizoidia was initially considered to describe features both of the premorbid personality of schizophrenic patients and of the personalities of non-psychotic family members (Bleuler, Kahlbaum, Kraepelin). On a psychopatholocial level a close link to the complex basic symptom of autism was stressed. From the very beginnings of modern psychiatry schizoidia was discussed within a conceptual frame of schizophrenia spectrum disorders (Kretschmer, Hoch, Polatin). Approaches to operationalize these conceptual works laid the basis for the cluster A personalities in DSM-III. Due to the prominent concept of schizotypy (Kety, Rado, Meehl) three split up diagnostic categories of schizotypal, schizoid and paranoid personality disorders resulted. Cluster A personality disorders are frequent in community-based epidemiological studies. Health-care seeking behaviour due to primary personality-related problems, however, seems to be less paramount compared to cluster B and C personality disorders. Many family- and twin-based genetic studies convincingly stress a close link between schizotypal personality disorder and schizophrenia. This link is less pronounced for paranoid personality disorder, and even vanishingly low for schizoid personality disorder. From a perspective of schizophrenia spectrum disorders a vast amount of data from molecular genetic, neurobiological, neuropsychological and psychosocial research has impressingly confirmed this link for schizotypal personality disorder. Major research deficits, however, have to be noticed for paranoid and schizoid personality disorder.

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) was published by the American Psychiatric Association (APA) in 2013, and the Work Group on the Classification of Psychotic disorders (WGPD), installed by the World Health Organization (WHO), is expected to publish the new chapter about schizophrenia and other primary psychotic disorders in 2017. We reviewed the available literature to summarize the major changes, innovations, and developments of both manuals. If available and possible, we outline the theoretical background behind these changes. Due to the fact that the development of ICD-11 has not yet been completed, the details about ICD-11 are still proposals under ongoing revision. In this ongoing process, they may be revised and therefore have to be seen as proposals. DSM-5 has eliminated schizophrenia subtypes and replaced them with a dimensional approach based on symptom assessments. ICD-11 will most likely go in a similar direction, as both manuals are planned to be more harmonized, although some differences will remain in details and the conceptual orientation. Next to these modifications, ICD-11 will provide a transsectional diagnostic criterion for schizoaffective disorders and a reorganization of acute and transient psychotic and delusional disorders. In this manuscript, we will compare the 2 classification systems.

Background: Many patients with psychiatric and organic disorders may present primary or secondary psychotic symptoms. Based on the ICD 10 classification, this article describes the possible underlying diseases and their subdivision. The main focus will be differential-diagnostic evaluations of psychotic syndromes., Results: In the clinical setting, the differential diagnosis of the paranoid schizophrenia and other psychotic disorders into three main disease groups is important: 1. other psychiatric diseases, 2. primary and secondary organic diseases and 3. autoimmune diseases. The first group contains, for example, drug-induced psychoses, affective disorders, personality disorders. The second group includes forms of dementia, forms of deliria or metabolic diseases. Recently, another focus is set on autoimmune diseases, especially encephalitides., Summary: A detailed medical history, a physical examination and organic diagnostic can lead to the correct diagnosis and therapy. The differential-diagnostic classification and the detection of organic causes is an important part of psychiatric care, but often a good cooperation with organic specialties is needed., (© Georg Thieme Verlag KG Stuttgart · New York.)

The short version of the Oxford-Liverpool Inventory of Feelings and Experiences (sO-LIFE) is a widely used measure assessing schizotypy. There is limited information, however, on how sO-LIFE scores compare across different countries. The main goal of the present study is to test the measurement invariance of the sO-LIFE scores in a large sample of non-clinical adolescents and young adults from four European countries (UK, Switzerland, Italy, and Spain). The scores were obtained from validated versions of the sO-LIFE in their respective languages. The sample comprised 4190 participants (M=20.87 years; SD=3.71 years). The study of the internal structure, using confirmatory factor analysis, revealed that both three (i.e., positive schizotypy, cognitive disorganisation, and introvertive anhedonia) and four-factor (i.e., positive schizotypy, cognitive disorganisation, introvertive anhedonia, and impulsive nonconformity) models fitted the data moderately well. Multi-group confirmatory factor analysis showed that the three-factor model had partial strong measurement invariance across countries. Eight items were non-invariant across samples. Significant statistical differences in the mean scores of the s-OLIFE were found by country. Reliability scores, estimated with Ordinal alpha ranged from 0.75 to 0.87. Using the Item Response Theory framework, the sO-LIFE provides more accuracy information at the medium and high end of the latent trait. The current results show further evidence in support of the psychometric proprieties of the sO-LIFE, provide new information about the cross-cultural equivalence of schizotypy and support the use of this measure to screen for psychotic-like features and liability to psychosis in general population samples from different European countries., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Early detection and treatment of illness are fundamental in providing optimal health care. However, this is a major challenge in mental illness, where diagnoses depend on symptom manifestation and the symptoms are often on a continuum with behaviors observed in the non-ill population. During the past 25 years, substantial progress has been made in identifying clinical high risk for psychoses with extensive validation and the beginning of treatment trials for symptom reduction and secondary prevention of psychoses. Attenuated psychosis syndrome is placed in Section 3 of the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, as a new disorder for further study. But the value and wisdom of creating a new disorder are hotly debated. The author advocates establishing a new disorder class as essential for progress. Key reasons to justify this view are described. Reasons to oppose the creation of a new class are briefly described.

Heterogeneity in the expression of schizotypy may arise from underlying dimensional processes or a taxonic population structure. In a 2-phase study, we tested the taxonicity of self-reported schizotypy within a general psychiatric sample (n = 109) and examined taxon validity by testing its association with clinical schizotaxia in follow-up subsamples. Taxometric analyses indicated a taxonic structure (schizotypy prevalence = 38.8%) provided the best description of the underlying population distribution. After a year, schizotypal (n = 14) and nonschizotypal (n = 14) subsamples returned for diagnosis of clinical schizotaxia by assessment of executive functioning, attention, memory, and negative symptoms. Seven patients met diagnostic criteria, all members of the schizotypy class. Schizotypy was associated with impaired attention and memory, more negative symptoms, poorer global functioning, and more extensive psychiatric histories. We reconcile inconsistencies in the literature by discussing threats to the validity of this and similar research on Meehl's taxonomic model of schizotypy, including conceptual limitations of the lexical hypothesis and conventions of factor analysis. Scrutiny of Meehl's model should involve disambiguation and better measurement of the schizotaxia-schizotypy phenotype., (© The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

This article introduces and reviews the history of the construct of schizotypy for the special section appearing in the journal. Schizotypy offers a useful construct for understanding the etiology, development, and expression of schizophrenia-spectrum psychopathology and a unifying construct for linking a broad continuum of clinical and subclinical manifestations. The article reviews the descriptive psychopathology roots of schizotypy, Meehl and Claridge's classical formulations of the construct (including the debate about dimensional vs taxonic structure), and the need for a comprehensive, multidimensional model of schizotypy. The article briefly reviews the wide empirical literature supporting schizotypy and also examines several criticisms and misconceptions about the construct and research methods used to assess it. Finally, the article offers several suggested goals for future schizotypy research., (© The Author 2014. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The concept of schizotypy represents a rich and complex psychopathology construct. Furthermore, the construct implies a theoretical model that has considerable utility as an organizing framework for the study of schizophrenia, schizophrenia-related psychopathology (eg, delusional disorder, psychosis-NOS (not otherwise specified), schizotypal, and paranoid personality disorder), and putative schizophrenia endophenotypes as suggested by Rado, Meehl, Gottesman, Lenzenweger, and others. The understanding (and misunderstanding) of the schizophrenia-related schizotypy model, particularly as regards clinical illness, as well as an alternative approach to the construct require vigilance in order to ensure the methodological approach continues to yield the fruit that it can in illuminating the pathogenesis of schizophrenia-related psychopathology. The articles in the Special Section in this issue of Schizophrenia Bulletin highlight methodological and theoretical issues that should be examined carefully., (© The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

A critical analysis of the main concepts of schizophrenia (from the Kraepelin paradigm to the current studies attempted to «destruct» schizophrenia as nosologically independent disease) is presented. In author's opinion, the elimination of schizophrenia may lead to negative consequences as in aspect of clinical practice (the diagnosis of schizophrenia provides information about disease course, clinical and social outcomes) as well as in aspect of denial of autochthonous (endogenous) origin of mental disorders that fall under this definition. Based on the current level of knowledge, manifestation of these disorders can't be well explained by the adverse effects of situational, psychogenic or somatogenic factors. The restriction of the definition of schizophrenia («process» schizophrenia) should be brought about by the elimination of a group of schizophrenia spectrum disorders (schizotypal disorder, schizoaffective disorder, delusional psychosis).

Findings on the population distribution of schizotypy consistently point toward an underlying class structure. However, past research is methodologically homogeneous, chiefly involving analysis of attribute-specific indicators and coherent cut kinetic methods such as maximum covariance (MAXCOV) analysis. Two questions are examined. Are different or overlapping classes identified from different attributes of the schizophrenia phenotype? Do fundamentally different approaches to analysis yield consistent results? Participants (n=1074) completed the Schizotypal Personality Questionnaire (SPQ). Following item screening, MAXCOV analyses were conducted iteratively on attribute-specific item sets (cognitive-perceptual, interpersonal, and disorganized) and a general item set. Latent variable modeling (factor analysis, latent class analysis, and factor-mixture modeling) was used to examine the consistency of the MAXCOV results using items retained in the general set following MAXCOV analysis. Attribute-specific and general item sets gave taxonic MAXCOV curves and base rates of 8.4-10.4% and 3.6%, respectively. Classes were not independent. No latent variable model emerged as uniquely superior but five models distinguished a small high-scoring class populated by members of the MAXCOV general class. Different attributes distinguished overlapping yet nonredundant taxa, and a general schizotypy taxon identified with MAXCOV was also identified in latent variable modeling., (© 2013 Elsevier Ireland Ltd. All rights reserved.)

Background: Misophonia, or selective sound sensitivity syndrome, is a preoccupation with or aversion to certain types of sounds that evokes feelings of irritability, disgust, or anger. Recently, it has been suggested that misophonia is a discrete clinical entity deserving of its own place in psychiatric diagnostic manuals. In this paper, we describe 3 patients whose misophonia could be attributed to different underlying primary psychiatric disorders., Methods: Case series report., Results: In these patients, we argue that misophonia is better described as a symptom of a) obsessive-compulsive disorder, b) generalized anxiety disorder, and c) schizotypal personality disorder., Conclusions: The nosological status of misophonia remains a matter of debate. Patients who exhibit misophonia as a major complaint should be assessed for other conditions. Further studies on the prevalence, natural history, and additional features of misophonia are needed.

In the process of revising ICD-10, the World Health Organization (WHO) has appointed a Working Group on the Classification of Psychotic Disorders (WGPD). Several changes to the classification criteria of schizophrenia and other primary psychotic disorders have been proposed with the aim of increasing the clinical utility, reliability and validity of the diagnostic classification. These proposals will be tested in field trials and subsequently revised according to the needs of clinical practice before final publication in 2015. The main proposals include the following: change of the chapter title, the replacement of the present schizophrenia subtypes with symptom specifiers, a revision of course specifiers, the inclusion of stricter diagnostic criteria for schizoaffective disorder, and a reorganization of acute and transient psychotic disorders and delusional disorders. The proposals for ICD-11 are compared with those for the corresponding DSM-5 chapter., (Copyright © 2013. Published by Elsevier B.V.)

Despite growing enthusiasm for dimensional models of personality pathology, the taxonic versus dimensional status of schizotypal personality disorder (PD) remains a point of contention in modern psychiatry. The current study aimed to determine empirically the latent structure of schizotypal PD. We examined the latent structure of schizotypal PD in the Psychiatric Morbidity Survey in Great Britain and the second wave of the U.S.-based National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) survey. We analyzed composite indicators created from participant responses using the mean above minus mean below a cut (MAMBAC), Maximum Covariance (MAXCOV), and latent mode factor analysis (L-Mode) taxometric procedures. We also analyzed item-level responses using two latent variable mixture models--latent class analysis and latent class factor analysis. Taxometric and latent variable mixture analyses supported a dimensional, rather than taxonic, structure in both epidemiological samples. The dimensional model better predicted psychosis, intellectual functioning, disability, and treatment seeking than the categorical model based on DSM-IV diagnosis. People meeting criteria for schizotypal PD appear to exist on a spectrum of severity with the rest of the population. The possible dimensionality of schizotypal PD adds to growing support for a dimensional structure of PDs including other Cluster A disorders., (© 2013 American Psychological Association)

Within the efforts to revise ICD-10 and DSM-IV-TR, work groups on the classification of psychotic disorders appointed by the World Health Organization (WHO) and the American Psychiatric Association (APA) have proposed several changes to the corresponding classification criteria of schizophrenia and other psychotic disorders in order to increase the clinical utility, reliability and validity of these diagnoses. These proposed revisions are subject to field trials with the objective of studying whether they will lead to an improvement of the classification systems in comparison to their previous versions. Both a challenge and an opportunity, the APA and WHO have also considered harmonizing between the two classifications. The current status of both suggests that this goal can only be met in part. The main proposed revisions include changes to the number and types of symptoms of schizophrenia, the replacement of existing schizophrenia subtypes with dimensional assessments or symptom specifiers, different modifications of the criteria for schizoaffective disorder, a reorganization of the delusional disorders and the acute and transient psychotic disorders in ICD-11, as well as the revision of course and psychomotor symptoms/catatonia specifiers in both classification systems.

Objectives: Multiple complex developmental disorder (MCDD) is a little-known disorder characterized by disturbances in the regulation of emotions, social interactions and thought disorders. Neither the classification system of ICD-10 nor the DSM-IV lists MCDD as an independent disorder., Methods: The study presents an overview on diagnostic criteria, current research and illustration by a case report of a 17-year-old adolescent., Results: MCDD, autistic disorders and schizophrenic disorders partially overlap. A clear classification or differentiation is currently not clearly possible., Conclusions: Many open questions remain, and further research is needed.

The identification of individuals carrying unexpressed genetic liability to schizophrenia is crucial for both etiological research and clinical risk stratification. Subclinical psychopathological features detectable in the nonpsychotic part of the schizophrenia spectrum could improve the delineation of informative vulnerability phenotypes. Inspired by Meehl's schizotaxia-schizotypy heuristic model, we tested anomalous subjective experiences (self-disorders, SDs) as a candidate vulnerability phenotype in a sample of nonpsychotic, genetically high-risk subjects. A total of 218 unaffected members of 6 extended multiplex families (assessed between 1989 and 1999 during the Copenhagen Schizophrenia Linkage Study) were stratified into 4 groups of increasing psychopathological expressivity: no mental illness (NMI), no mental illness with schizotypal traits (NMI-ST), personality disorders not fulfilling other personality disorders (OPDs), and schizotypal personality disorder (SPD). We tested the distribution of SDs among the subgroups, the effect of SDs on the risk of belonging to the different subgroups, and the effect of experimental grouping and concomitant psychopathology (ie, negative symptoms (NSs) and subpsychotic formal thought disorder [FTD]) on the chances of experiencing SDs. SDs distribution followed an incremental pattern from NMI to SPD. SDs were associated with a markedly increased risk of NMI-ST, OPDs, or SPD. The odds of SDs increased as a function of the diagnostic category assignment, independently of sociodemographics and concomitant subclinical psychopathology (NSs and FTD). The results support SDs as an expression of schizotaxic vulnerability and indicate a multidimensional model of schizotypy--characterized by SDs, NSs, FTD--as a promising heuristic construct to address liability phenotypes in genetically high-risk studies.

The conceptual issues are briefly noted with respect to the distinctions between classification and diagnosis; the question of whether mental disorders can be considered to be 'diseases'; and whether descriptive psychiatry is outmoded. The criteria for diagnosis are reviewed, with the conclusion that, at present, there are far too many diagnoses, and a ridiculously high rate of supposed comorbidity. It is concluded that a separate grouping of disorders with an onset specific to childhood should be deleted, the various specific disorders being placed in appropriate places, and the addition for all diagnoses of the ways in which manifestations vary by age. A new group should be formed of disorders that are known to occur but for which further testing for validity is needed. The overall number of diagnoses should be drastically reduced. Categorical and dimensional approaches to diagnosis should be combined. The requirement of impairment should be removed from all diagnoses. Research and clinical classifications should be kept separate. Finally, there is a need to develop a primary care classification for causes of referral to both medical and non-medical primary care., (© 2011 The Author. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.)

Research on the sub-clinical condition of schizotypy suggests that it is associated with mixed handedness. To date, however, this research has focussed on undergraduate populations. If the association between schizotypy and mixed-handedness is the result of an underlying neurological trait, it is important to demonstrate that the effect extends to the general population. With this in mind, 699 participants were drawn from a wide community sample. Schizotypy was measured using the Psychosis Proneness Questionnaire and handedness was assessed using the Annett inventory. To avoid the sometimes arbitrary definitions of left-, right- and mixed-handed, regression analyses were used to explore the data. There was no evidence of a difference in schizotypy between individuals with a left- or right-hand preference. People with a mixed-hand preference, however, had higher scores on PER-MAG (Perceptual Aberration and Magical Ideation) and HYP-IMP (Hypomania and Impulsive Non-Conformity) scales (positive traits). No effect was observed for the SAN (Social Anhedonia) and PAN (Physical Anhedonia) scales (negative traits). The nature of the association between schizotypy and handedness observed in the current study is similar to that reported for student populations. The possibility that the association is related to response biases or a biological mechanism is discussed., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Psychometric case identification of individuals at risk for developing schizophrenia-spectrum disorders is an important enterprise. Unfortunately, current instruments for this purpose are limited. The present studies sought to improve the Schizotypal Personality Questionnaire-Brief (SPQ-Brief), a measure of schizotypal traits that has come under recent criticism. In the first study, we conducted exploratory factor analysis on the SPQ-Brief using a Likert-style scoring format in a large sample of nonclinical adults. Although acceptable internal consistency was found, the original factor structure was not supported. In the second study, we administered the full version of the SPQ to a separate large nonclinical adult sample and employed exploratory and confirmatory factor analysis to identify critical items that could be used to revise the SPQ-Brief. The end product of these studies is the SPQ-Brief Revised, which offers a subordinate seven-factor and super-ordinate three or four factor solution, employs a Likert-scale format to improve sensitivity, and is brief (34 items).

Objectives: To obtain data and hypotheses regarding the amelioration of risk estimation and preventive psychotherapy in patients in a prodromal state of schizophrenia by using OPD., Methods: 20 participants with a prodromal condition--6 subjects far from psychosis and 14 close to psychosis--along with 10 patients with paranoid schizophrenia as reference group were examined using the first four OPD axes., Results: Both groups differed considerably in all four axes. Compared to the schizophrenic participants, prodromal probands appear to have more favourable preconditions for therapy. Moreover, they experienced the interaction partners, including the investigator, as less aversive and induced less distanced behaviour in the investigator. Conflicts of self-esteem were prominent in both prodromal subgroups. However, patients farther from psychosis showed less conflicts of autonomy versus dependence and displayed a higher integration in structures such as "defence" and "attachment" when compared to participants closer to psychosis., Conclusions: Particularly the differences between the prodromal subgroups suggest that application of the OPD may positively complement previous approaches of early detection, prevention,and psychotherapy for prodromal conditions. The hypotheses obtained should be tested in longitudinal studies with larger sample sizes.

Background: In an effort to group mental disorders on the basis of etiology, five clusters have been proposed. Here we consider the validity of the cluster comprising selected psychotic and related disorders., Method: A group of diagnostic entities classified under schizophrenia and other psychotic disorders in DSM-IV-TR were assigned to this cluster and the bordering disorders, bipolar (BD) and schizotypal personality disorders (SPD), were included. We then reviewed the literature in relation to 11 validating criteria proposed by the DSM-V Task Force Study Group., Results: Relevant comparisons on the 11 spectrum criteria are rare for the included disorders except for schizophrenia and the two border conditions, BD and SPD. The core psychosis group is congruent at the level of shared psychotic psychopathology and response to antipsychotic medication. BD and SPD are exceptions in that psychosis is not typical in BD-II disorder and frank psychosis is excluded in SPD. There is modest similarity between schizophrenia and BD relating to risk factors, neural substrates, cognition and endophenotypes, but key differences are noted. There is greater support for a spectrum relationship of SPD and schizophrenia. Antecedent temperament, an important validator for other groupings, has received little empirical study in the various psychotic disorders., Conclusions: The DSM-IV-TR grouping of psychotic disorders is supported by tradition and shared psychopathology, but few data exist across these diagnoses relating to the 11 spectrum criteria. The case for including BD is modest, and the relationship of BD to other mood disorders is addressed elsewhere. Evidence is stronger for inclusion of SPD, but the relationship with other personality disorders along the 11 criteria is not addressed and the absence of psychosis presents a conceptual problem. There are no data along the 11 spectrum criteria that are decisive for a cluster based on etiology, and inclusion of BD and SPD is questionable.

Evaluation of the validity of personality disorder (PD) diagnostic constructs is important for the impending revision of the Diagnostic and Statistical Manual of Mental Disorders. Prior factor analytic studies have tested these constructs in cross-sectional studies, and models have been replicated longitudinally, but no study has tested a constrained longitudinal model. The authors examined 4 PDs in the Collaborative Longitudinal Personality Disorders study (schizotypal, borderline, avoidant, and obsessive-compulsive) over 7 time points (baseline, 6 months, 1 year, 2 years, 4 years, 6 years, and 10 years). Data for 2-, 4-, 6- and 10-year assessments were obtained in semistructured interviews by raters blind to prior PD diagnoses at each assessment. The latent structure of the 4 constructs was differentiated during the initial time points but became less differentiated over time as the mean levels of the constructs dropped and stability increased. Obsessive-compulsive PD became more correlated with schizotypal and borderline PD than with avoidant PD. The higher correlation among the constructs in later years may reflect greater shared base of pathology for chronic personality disorders.

This overview briefly presents recent thinking on the dimensional approach to understanding psychotic experiences. First, evidence is provided for a continuum of psychosis ranging from self-reported infrequent psychotic symptoms in the general population, to schizotypal traits, to schizotypal personality disorder, and finally to full-blown psychosis resulting in a diagnosable primary psychotic disorder. Variation within each of these types of psychotic experience is discussed. Then, a comparison is presented between categorical and dimensional approaches to the diagnosis of psychosis by highlighting four advantages of each approach. In doing so, it is emphasized that the categorical approach is beneficial primarily in terms of reliability, whereas the dimensional approach would enhance validity.

Participants scoring high and low on a schizotypy scale (n=18 in each group) switched between naming words and naming colors in a Stroop task in congruent, neutral, and incongruent conditions. The findings were that, while being slower and less accurate overall than low schizotypes, the high schizotypy group did not display disproportionately greater Stroop inhibition or facilitation, suggesting intact selective attention. However, the high schizotypy group suffered disproportionately larger switching costs. The results provide evidence for similarities between schizotypy and schizophrenia, specifically that the problem in schizotypy is to do with switching rather than selecting attention, because of a difficulty either in selecting task-relevant information or in inhibiting inappropriate response alternatives.

Recent exchanges on the place of hypohedonia within Meehl's theory of schizotaxia, schizotypy, and schizophrenia focus on evidence of the taxonicity of asociality, not hedonic capacity per se. Two hypotheses were contrasted, one that hypohedonia is a nonpathological individual difference variable independent of schizotypy, the other that schizotypy and hypohedonia tap independent taxonic processes that predict the emergence of positive and negative signs of schizophrenia, respectively. Undergraduates (n = 1,543) completed a multifaceted measure of schizotypy and hypohedonia. A consecutive subsample of these (n = 284) also completed a continuous performance test and the Symptom Checklist 90-Revised. Independent taxometric analyses (maximum covariance and maximum eigenvalue) indicated schizotypy was taxonic and hypohedonia was dimensional. Their coincidence was no greater than chance. Schizotypy was associated with impaired attention and significant psychological distress, whereas hypohedonia was not. Hypohedonia does not behave like a core component of schizotypy.

Obsessive-compulsive (OC) and schizotypal symptoms are highly correlated in clinical samples. The current study investigated the presence of schizotypal and OC symptomatology in a large undergraduate sample using factor and cluster analysis and t test comparison of cluster groups. Separate clusters of individuals reporting high levels of schizotypal and OC symptoms versus purely schizotypal symptoms emerged and demonstrated different overall symptom profiles. Individuals with high levels of pure schizotypy symptoms demonstrated a prevalence of interpersonal symptoms, including restricted affect, and few close friends. In contrast, those with high levels of both schizotypy and OC symptoms demonstrated higher cognitive/perceptual symptoms, including ideas of reference and suspiciousness. Consistent with research in clinical populations, results suggest greater prevalence of positive symptoms in individuals experiencing both schizotypal and OC disorder symptoms.

This study used a multi-sample, multiple-instrument strategy to evaluate the hypothesis that schizotypal personality disorder (SPD) is taxonic. In Study 1, 721 consecutively admitted inpatients and outpatients were evaluated with the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II) and the Personality Diagnostic Questionnaire-4+ (PDQ-4+). The data from both questionnaire types were submitted to multivariate normal mixture analysis, which was carried out on factor scores obtained from a three-factor model of SPD criteria; these results supported the hypothesis that SPD is taxonic. The same was true of Study 2, which administered the Semi-structured Interview for DSM-III-R Personality Disorders (SIDP-R) to an independent sample of 537 consecutively admitted outpatients. Similar findings were observed in Study 3, in which the SIDP-R was administered to 225 non-clinical subjects. The results show that the typology of DSM III-R and -IV SPD diagnosis is consistent with the latent structure of SPD features.

Objective: It is suggested that schizophrenic patients who respond to neuroleptic medication and those who do not might differ with respect to their pathogenesis. In particular, it has been proposed that genetic factors may contribute to treatment response and/or outcome. In order to test this hypothesis, we compared the pattern of familial aggregation of schizophrenia related disorders in schizophrenic patients who are either responders (R) or nonresponders (NR) to typical neuroleptics., Method: R (n=36) or NR (n=35) patients to typical neuroleptics and healthy controls (n=63) were recruited. At least one key informant relative of each proband was interviewed blind as to the status of the proband using the Family Interview for Genetic Studies. Morbid risk for schizophrenia and cluster A personality disorders and family loading score for schizophrenia were examined in first- and second-degree relatives of these probands., Results: First-degree relatives of NR patients were at a significantly higher risk for schizophrenia (MR=8.84), compared, respectively, to relatives of controls (MR=1.52) or relatives of R patients (MR=2.45). The same pattern was observed in second-degree relatives. Family loading score for schizophrenia in first- and second-degree relatives was significantly higher in NR compared to R patients., Conclusions: Schizophrenic patients who do not respond to typical neuroleptics may suffer from a more familial form of schizophrenia compared to patients who are responders.

Background: The clinical picture of schizotypal disorders is rarely comprehensively described., Aims: To describe psychopathological profiles of patients with ICD-10 schizotypal disorder., Method: A total of 151 first-admitted patients (with affective and somatic disorders excluded) were given a comprehensive psychopathological evaluation, including the Bonn Scale for the Assessment of Basic Symptoms. Patients with schizotypal disorder (n=50) were compared with those with psychosis (n=51) and those outside the schizophrenia spectrum (other diagnoses, n=50) on a number of psychopathological scales., Results: Patients with schizotypal disorder scored intermediately between patients with psychosis and other diagnoses on scales related to positive and negative symptoms, disorders of emotional contact and formal thought disorder, but had the same scores as patients with schizophrenia for subtle aberrations of subjective experience. Schizotypal criteria were not normally distributed with an excess of patients between 2 and 6 criteria. Family history of schizophrenia was equally elevated among those with schizotypal disorder and those with psychosis., Conclusions: ICD-10 schizotypy represents a milder, less psychotic, variant of schizophrenia but there is no clear-cut division between the two disorders.

The 16-channel EEG records of 45 adolescents with schizophrenia and 39 healthy adolescents were subjected to statistical combinatorial analysis of 160 elementary EEG characteristics (6 spectral and 4 segmental EEG characteristics for a channel). Employing pattern recognition algorithm "Kora-n", a list of 37 combined EEG patterns was compiled. This list characterized with a minimal error the EEG of healthy adolescents in such a way that none of these characters featured the EEG of adolescents with schizophrenia. Analysis of this list of EEG characteristics suggests that the contrast between EEG of healthy and ill adolescents is the sharpest in the F4, Cz, T3 and O1 derivations. Compared to EEG samples of schizophrenic subjects, EEGs of healthy subjects exhibit lower levels of delta and theta activity mainly in the frontal and temporal regions of the cortex and higher level of alpha activity predominantly in the occipital region. Applicability of the list of EEG patterns for diagnostics of schizophrenia-type disorders of adolescents is discussed.