Schizotypal personality disorder or prodromal symptoms of schizophrenia?

Neurocognitive performance and cognitive biases in young adults with schizotypal traits

Recent research suggests that neurocognitive deficits in patients with schizophrenia may increase the risk of developing cognitive biases. As such, we set out to determine this predictive relationship as it pertains to the development of a first-episode psychosis. We hypothesized that poorer performance in processing speed would be associated with jumping to conclusions and an externalizing bias. Poorer performance in working memory would be associated with belief inflexibility and jumping to conclusions, and poorer performance in attention would be associated with attention to threat. We hypothesized that all cognitive biases would be associated with subsyndromal positive symptoms, and schizotypal traits would moderate these relationships. Undergraduate students (N = 130) completed the Schizotypal Personality Questionnaire, DAVOS Assessment of Cognitive Biases, Community Assessment of Psychic Experiences, and a computerized neuropsychological assessment battery. Processing speed had a small effect on externalizing bias, which in turn affected subsyndromal positive symptoms. There was no moderating effect of schizotypal traits on externalizing bias, but it was significantly associated with subsyndromal positive symptoms. Only the externalizing bias was associated with subsyndromal positive symptomatology, which might be explained by a restricted range and reduced variance in performance as a result of using a university student sample. This is one of few studies that sought to explain the mechanism responsible for the development of subsyndromal positive symptoms in a healthy sample using self-report measures.

The exploration of a screen model for detecting undergraduates at higher risk for developing psychosis: A cross-sectional study in a medical university

PURPOSE

To examine a screen model for detecting undergraduates with higher risk for developing psychosis (HRDP).

DESIGN AND METHODS

A cross-sectional design with convenience sampling was used. The screen model included exploration stage by self-report scales and confirmation stage by face-to-face interviews.

FINDINGS

A total of 273 students were detected from 4744 surveys during 4 years. Of them, 120 students with HRDP were identified and 7 had been diagnosed as schizophrenia or bipolar disorders at 12-month follow-up.

PRACTICE IMPLICATIONS

This screen model can be used in early detection for undergraduates with HRDP from large general samples.

[History of the formation of views on schizotypal disorder in childhood]

The article reflects the stages of development of views on schizotypal disorder (STD) in adults and children from the prenosological period to the present. It is shown how, after the recognition by the majority of psychiatrists of the concept of early dementia proposed by E. Kraepelin, there is a gradual recognition of the single essence of schizophrenia for childhood and adulthood, but with different, specific clinical manifestations at different age periods. The study of variants of schizophrenia without a fatal outcome in dementia, which led to the isolation of sluggish schizophrenia, including in childhood, begins with the works of E. Bleuler. The differences in approaches to the study and interpretation of sluggish schizophrenia in Russian, European and American psychiatry, which led to the isolation of STEs in the framework of personality disorders, are described. Three main concepts that exist at the present stage of research are presented, in which STD is considered as an independent disease in the spectrum of schizophrenic disorders, as one of the types of personality deviations with a high degree of vulnerability for the development of schizophrenia, and as one of the forms of the disease.

A preliminary study on the effectiveness of a stress management program for healthcare-related undergraduates with at-risk mental state

PURPOSE

This study aimed to examine the effects of a stress management program on stress perception and coping strategies for healthcare-related undergraduates with at-risk mental state (ARMS).

DESIGN AND METHODS

A randomized experimental design with pretest and posttest was used. Of the 2812 students screened, 65 were identified as having ARMS, 52 enrolled in the study, and 49 (75%) completed the study.

FINDINGS

Significance was found for subjects with schizotypal traits in emotion expression and problem-avoidance coping strategies. Subjects with trait anxiety improved significantly in interpersonal deficits after the program.

PRACTICE IMPLICATIONS

Students with different trait risks reported benefits in different stress-coping strategies from the program.

Common Taxonomy of Traits and Symptoms: Linking Schizophrenia Symptoms, Schizotypy, and Normal Personality

The associations among normal personality and many mental disorders are well established, but it remains unclear whether and how symptoms of schizophrenia and schizotypal traits align with the personality taxonomy. This study examined the joint factor structure of normal personality, schizotypy, and schizophrenia symptoms in people with psychotic disorders (n = 288) and never-psychotic adults (n = 257) in the Suffolk County Mental Health Project. First, we evaluated the structure of schizotypal (positive schizotypy, negative schizotypy, and mistrust) and normal traits. In both the psychotic-disorder and never-psychotic groups, the best-fitting model had 5 factors: neuroticism, extraversion, conscientiousness, agreeableness, and psychoticism. The schizotypy traits were placed on different dimensions: negative schizotypy went on (low) extraversion, whereas positive schizotypy and mistrust went on psychoticism. Next, we added symptoms to the model. Numerous alternatives were compared, and the 5-factor model remained best-fitting. Reality distortion (hallucinations and delusions) and disorganization symptoms were placed on psychoticism, and negative symptoms were placed on extraversion. Models that separated symptom dimensions from trait dimensions did not fit well, arguing that taxonomies of symptoms and traits are aligned. This is the first study to show that symptoms of psychosis, schizotypy, and normal personality reflect the same underlying dimensions. Specifically, (low) extraversion, negative schizotypy, and negative symptoms form one spectrum, whereas psychoticism, positive schizotypy, and positive and disorganized symptoms form another. This framework helps to understand the heterogeneity of psychosis and comorbidity patterns found in psychotic disorders. It also underscores the importance of traits to understanding these disorders.

The Schizotypal Personality Questionnaire - Child (SPQ-C): Psychometric properties and relations to behavioral problems with multi-informant ratings

The Schizotypal Personality Questionnaire (SPQ) is one of the most widely used screening tools for schizotypy in adults. The Schizotypal Personality Questionnaire-Child version (SPQ-C) was recently developed to assess schizotypy in children and has a similar three-factor structure to the adult SPQ (i.e., Cognitive-Perceptual, Interpersonal-Affective, and Disorganization). However, few studies to date have reported on the psychometric properties and the usefulness of the SPQ-C in Eastern populations, including Mainland China. This study presents the first psychometric assessment of the Chinese SPQ-C in Mainland China. Exploratory factor analysis and confirmatory factor analysis were used to assess the factor structure of the SPQ-C in 1668 children (M = 12.10, SD = 0.60 years) from the China Jintan Child Cohort Study. Our findings document a three-factor structure and partial measurement invariance across residential location and gender, replicating the psychometric properties of the SPQ-C in English. The Chinese SPQ-C further correlates with standard behavioral problems (i.e., Child Behavior Checklist, Youth Self-Report and Teacher Report Form), demonstrating construct validity and utility as a child psychopathology assessment tool. Our findings provide the first robust psychometric evidence for a three-factor structure of the Chinese SPQ-C in a large Mainland Chinese sample, and suggest that the SPQ-C is suitable as a screening tool for schizotypy in community children who may be at risk for behavioral problems and later psychosis.

Psychosis risk screening: Validation of the youth psychosis at-risk questionnaire - brief in a community-derived sample of adolescents

There have been several attempts to identify individuals potentially at high risk for psychotic-spectrum disorders using brief screening measures. However, relatively few studies have tested the psychometric properties of the psychosis screening measures in representative samples of adolescents. The main purpose of the present study was to analyse the prevalence, factorial structure, measurement invariance across gender, and reliability of the Youth Psychosis At-Risk Questionnaire - Brief (YPARQ-B) in a community-derived sample of adolescents. Additionally, the relationship between YPARQ-B, depressive symptoms, psychopathology, stress manifestations, and prosocial skills was analysed. One thousand and twenty students from high schools participated in a cross-sectional survey. The YPARQ-B, the Reynolds Adolescent Depression Scale, the Strengths and Difficulties Questionnaire, and the Student Stress Inventory - Stress Manifestations were used. A total of 85.1% of the total sample self-reported at least one subclinical psychotic experience. We observed a total of 10.9% of adolescents with a cutoff score of ≥11 or 6.8% with a cutoff score of ≥13. The analysis of internal structure of the YPARQ-B yielded an essentially unidimensional structure. The YPARQ-B scores showed measurement invariance across gender. The internal consistency of the YPARQ-B total score was 0.94. Furthermore, self-reported subclinical psychotic experiences were associated with depressive symptoms, emotional and behavioural problems, poor prosocial skills, and stress manifestations. These results would appear to indicate that YPARQ-B is a brief and easy tool to assess self-reported subclinical psychotic experiences in adolescents from the general population. The assessment of these experiences in community settings, and its associations with psychopathology, may help us to enhance the possibility of an early identification of adolescents potentially at risk for psychosis and mental health problems.

Co-morbidity of personality disorder in schizophrenia among psychiatric outpatients in China: data from epidemiologic survey in a clinical population

BACKGROUND

The reported rates of personality disorder (PD) in subjects with schizophrenia (SZ) are quite varied across different countries, and less is known about the heterogeneity of PD among subjects with SZ. We examined the co-morbidity of PD among patients who are in the stable phase of SZ.

METHOD

850 subjects were randomly sampled from patients diagnosed with SZ in psychiatric and psycho-counseling clinics at Shanghai Mental Health Center. Co-morbidity of PDs was assessed through preliminary screening and patients were administered several modules of the SCID-II. Evidence of heterogeneity was evaluated by comparing patients diagnosed with SZ with those who presented with either affective disorder or neurosis (ADN).

RESULTS

204 outpatients (24.0 %) in the stable phase of SZ met criteria for at least one type of DSM-IV PD. There was a higher prevalence of Cluster-A (odd and eccentric PD) and C (anxious and panic PD) PDs in SZ (around 12.0 %). The most prevalent PD was the paranoid subtype (7.65 %). Subjects with SZ were significantly more likely to have schizotypal PD (4.4 % vs. 2.1 %, p = 0.003) and paranoid PD (7.6 % vs. 5.4 %, p = 0.034), but much less likely to have borderline, obsessive-compulsive, depressive, narcissistic and histrionic PD.

CONCLUSIONS

These findings suggest that DSM-IV PD is common in patients with SZ than in the general population. Patterns of co-morbidity with PDs in SZ are different from ADN.

Assessing self-reported clinical high risk symptoms in community-derived adolescents: A psychometric evaluation of the Prodromal Questionnaire-Brief

BACKGROUND

The reliable early identification of individuals at risk for psychosis requires well-validated screening measures. To date, there is little information about the psychometric properties of the screening measures for psychosis risk in nonclinical adolescents. The main purpose of the present study was to validate the Prodromal Questionnaire-Brief (PQ-B) in a community sample of non-clinical Spanish adolescents. We also analyzed the prevalence, factorial validity, and reliability of the PQ-B scores as well as the relationship between self-reported clinical high risk symptoms and schizotypal traits.

METHOD

Four hundred and forty-nine high-school students participated in a cross-sectional survey. The PQ-B and the Oviedo Schizotypy Assessment Questionnaire (ESQUIZO-Q) were used.

RESULTS

Although 85.1% of the total sample reported at least one clinical high risk symptom, only 16% of the adolescents scored above the standardized cut-off. The PQ-B revealed an essentially unidimensional structure. The internal consistency of the PQ-B total score was 0.93. Pearson correlation coefficients indicated a high degree of overlap between self-reported clinical high risk symptoms and Positive and Disorganized schizotypal traits. A Canonical correlation between the PQ-B total score and ESQUIZO-Q dimensions showed that the associated variance between both sets of variables was 45.4% (adjusted R(2)=0.45).

CONCLUSIONS

The PQ-B is a brief, easy, and reliable tool for screening self-reported clinical high risk symptoms in adolescents from the general population. These results also indicated that self-reported clinical high risk symptoms and schizotypal traits are closely associated at the subclinical level. The assessment of psychosis risk symptoms and their relationship with other distal risk factors, in a close-in strategy, may enhance the early identification of individuals at heightened risk for psychosis spectrum disorders.

Screening schizotypal personality disorder for detection of clinical high risk of psychosis in Chinese mental health services

Schizotypal personality disorder (SPD) is viewed as a marker of prodromal psychosis. However, information regarding genetic risk (e.g. SPD) is often overlooked in the identification process. This study assessed whether SPD screening questionnaire help the prodromal psychosis (also widely applied "clinical high risk" (CHR) for clinical sample) detection in Chinese mental health service. This work also examined whether SPD had higher frequency in genetic risk population and CHR subjects. Two wave studies concerning the SPD identification was used for analysis. Wave 1 survey: 3075 subjects were assessed by Personality Diagnostic Questionnaire for SPD (PDQ-SPD) and Structured Clinical Interview for DSM-IV Axis II (SCID-II). Wave 2 survey: 2113 subjects screened with the prodromal questionnaire -brief version (PQ-B), PDQ-SPD, and interviewed by Structured Interview for Prodromal Symptoms (SIPS). Subjects with family history of mental disorders or with psychosis reported significantly higher scores in SPD. Receiver operating characteristic curves suggested that PDQ-SPD had moderate sensitivity and specificity for identifying CHR subjects. There was significant higher on SPD features in subjects with early stage (Course less than 1 year) of psychosis. Identifying SPD may be useful in early detection of psychosis especially in detecting the genetic risk syndromes and can be integrated with existing prodromal screen tools to improve its efficiency.

DSM-IV schizotypal personality disorder: a taxometric analysis among individuals with and without substance use disorders in the general population

This study examined the underlying structure of DSM-IV schizotypal personality disorder (SPD) among individuals with and without a substance use disorder. Using a nationally representative sample of U.S. adults, taxometric analyses were conducted on SPD in the total sample and among individuals with and without a substance use disorder. The structure of SPD in the total sample and among individuals without substance use disorders was dimensional (comparison curve fit indices (CCFI): 0.440, 0.365) whereas a taxonic structure was demonstrated among individuals with a substance use disorder (CCFI: 0.679). Taxonicity underlying schizotypy and SPD in prior taxometric research may have been the result of sampling high risk subsamples of the population. Taxometric research on SPD and other personality psychopathology among high risk subgroups of the population can help elucidate the complex etiology of SPD and the role played by comorbid substance use disorders in the expressivity of these disorders.

Psychosis risk screening: a systematic review

Despite the wealth of evidence linking duration of untreated psychosis to critical illness outcomes, most clinicians do not utilize any formal evaluation tools to identify attenuated or emerging psychotic symptoms. Given the costs associated with training and administration, interview-based assessments such as the Structured Interview for Psychosis Risk Syndromes (SIPS) are not likely to be widely adopted for clinical use. The ability to identify high-risk individuals through low-cost, brief methods is essential to the success of scalable prevention efforts. The aim of this article is to present a comprehensive review of the use of self-report forms as psychosis risk "screeners." A literature search revealed 34 investigations in which authors used a self-report questionnaire as a first-step screener in a clinical high-risk assessment protocol. Information about each screener, including reported psychometric data, is presented within the review. Psychosis risk screeners have been used in diverse samples with the goals of validating assessments, screening populations for clinical referral, recruiting samples of interest for research participation, and estimating symptom prevalence and severity. Screeners focusing on attenuated psychotic experiences appear to measure a reliable construct with variable prevalence in help-seeking and general population samples. Administration of screeners to help-seeking populations can identify enriched samples with substantially elevated likelihood of meeting CHR criteria and transitioning to psychosis over time. More research is needed, however, to establish reliable norms and screening thresholds, as score elevations indicating a likely high-risk respondent appear to be unreliable across populations and settings.

Schizotypal personality disorder

Early phenomenological descriptions of schizophrenia have acknowledged the existence of milder schizophrenia spectrum disorders characterized by the presence of attenuated symptoms typically present in chronic schizophrenia. The investigation of the schizophrenia spectrum disorders offers an opportunity to elucidate the pathophysiological mechanisms giving rise to schizophrenia. Differences and similarities between subjects with schizotypal personality disorder (SPD), the prototypical schizophrenia personality disorder, and chronic schizophrenia have been investigated with genetic, neurochemical, imaging, and pharmacological techniques. Patients with SPD and the more severely ill patients with chronic schizophrenia share cognitive, social, and attentional deficits hypothesized to result from common neurodevelopmentally based cortical temporal and prefrontal pathology. However, these deficits are milder in SPD patients due to their capacity to recruit other related brain regions to compensate for dysfunctional areas. Individuals with SPD are also less vulnerable to psychosis due to the presence of protective factors mitigating subcortical DA hyperactivity. Given the documented close relationship to other schizophrenic disorders, SPD will be included in the psychosis section of DSM-5 as a schizophrenia spectrum disorder as well as in the personality disorder section.

High-throughput cognitive assessment using BrainTest.org: examining cognitive control in a family cohort

Introduction Understanding the relationship between brain and complex latent behavioral constructs like cognitive control will require an inordinate amount of data. Internet-based methods can rapidly and efficiently refine behavioral measures in very large samples that are needed for genetics and behavioral research. Cognitive control is a multifactorial latent construct that is considered to be an endophenotype in numerous neuropsychiatric disorders, including attention deficit/hyperactivity disorder (ADHD). While previous studies have demonstrated high correlations between Web- and lab-based scores, skepticism remains for its broad implementation. Methods Here, we promote a different approach by characterizing a completely Web-recruited and tested community family sample on measures of cognitive control. We examine the prevalence of attention deficit symptoms in an online community sample of adolescents, demonstrate familial correlations in cognitive control measures, and use construct validation techniques to validate our high-throughput assessment approach. Results A total of 1214 participants performed Web-based tests of cognitive control with over 200 parent-child pairs analyzed as part of the primary study aims. The data show a wide range of "subclinical" symptomatology in a web community sample of adolescents that supports a dimensional view of attention and also provide preliminary narrow-sense heritability estimates for commonly used working memory and response inhibition tests. Conclusions Finally, we show strong face and construct validity for these measures of cognitive control that generally exceeds the evidence required of new lab-based measures. We discuss these results and how broad implementation of this platform may allow us to uncover important brain-behavior relationships quickly and efficiently.

Prediction of psychosis in clinical high-risk patients by the Schizotypal Personality Questionnaire. Results of the EPOS project

OBJECTIVE

Schizotypal features indicate proneness to psychosis in the general population. It is also possible that they increase transition to psychosis (TTP) among clinical high-risk patients (CHR). Our aim was to investigate whether schizotypal features predict TTP in CHR patients.

METHODS

In the EPOS (European Prediction of Psychosis Study) project, 245 young help-seeking CHR patients were prospectively followed for 18 months and their TTP was identified. At baseline, subjects were assessed with the Schizotypal Personality Questionnaire (SPQ). Associations between SPQ items and its subscales with the TTP were analysed in Cox regression analysis.

RESULTS

The SPQ subscales and items describing ideas of reference and lack of close interpersonal relationships were found to correlate significantly with TTP. The co-occurrence of these features doubled the risk of TTP.

CONCLUSIONS

Presence of ideas of reference and lack of close interpersonal relations increase the risk of full-blown psychosis among CHR patients. This co-occurrence makes the risk of psychosis very high.

Prevalence, correlates, disability, and comorbidity of DSM-IV schizotypal personality disorder: results from the wave 2 national epidemiologic survey on alcohol and related conditions

OBJECTIVE

To present nationally representative findings on the prevalence, correlates, and comorbidity of and disability associated with DSM-IV schizotypal personality disorder (SPD).

METHOD

This study used the 2004-2005 Wave 2 National Epidemiologic Survey on Alcohol and Related Conditions, which targeted a nationally representative sample of the adult civilian population of the United States aged 18 years and older and residing in households and group quarters. In Wave 2, attempts were made to conduct face-to-face reinterviews with all respondents to the Wave 1 interview.

RESULTS

Lifetime prevalence of SPD was 3.9%, with significantly greater rates among men (4.2%) than women (3.7%) (p < .01). Odds for SPD were significantly greater among black women, individuals with lower incomes, and those who were separated, divorced, or widowed; odds were significantly lower among Asian men (all p < .01). Schizotypal personality disorder was associated with substantial mental disability in both sexes. Co-occurrence rates of Axis I and other Axis II disorders among respondents with SPD were much higher than rates of co-occurrence of SPD among respondents with other disorders. After adjustment for sociodemographic characteristics and additional comorbidity, associations remained significant in both sexes between SPD and 12-month and lifetime bipolar I disorder, social and specific phobias, and posttraumatic stress disorder, as well as 12-month bipolar II disorder, lifetime generalized anxiety disorder, and borderline and narcissistic personality disorders (all p < .01).

CONCLUSIONS

Common and unique factors may underlie associations of SPD with narcissistic and borderline personality disorders, whereas much of the comorbidity between SPD and most mood and anxiety disorders appears to reflect factors common to these disorders. Some of the associations with SPD were sex specific. Schizotypal personality disorder and dependent, avoidant, and borderline personality disorders were associated with the occurrence of schizophrenia or psychotic episode. Schizotypal personality disorder is a prevalent, fairly stable, highly disabling disorder in the general population. Sex differences in associations of SPD with other specific Axis I and II disorders can inform more focused, hypothesis-driven investigations of factors underlying the comorbid relationships. Schizotypal as well as borderline, dependent, and avoidant personality disorders may be components of the schizophrenia spectrum.

Convergent and discriminant validity of attenuated psychosis screening tools

Brief self-report questionnaires that assess attenuated psychotic symptoms have the potential to screen many people who may benefit from clinical monitoring, further evaluation, or early intervention. The extent to which recently developed screening instruments demonstrate sound psychometric properties is an important issue toward the implementation of these measures in clinical practice. This study examines the convergent validity, discriminant validity, and test-retest reliability of four recently developed screening instruments. Screening instruments were included in an assessment battery and administered to a sample of 355 college students. Screening scores support the convergent and discriminant validity and the test-retest reliability of these measures.

Heritability and longitudinal stability of schizotypal traits during adolescence

The study investigated the genetic and environmental etiology of schizotypal personality traits in a non-selected sample of adolescent twins, measured on two occasions between the ages of 11 and 16 years old. The 22-item Schizotypal Personality Questionnaire- Child version (SPQ-C) was found to be factorially similar to the adult version of this instrument, with three underlying factors (Cognitive-Perceptual, Interpersonal-Affective, and Disorganization). Each factor was heritable at age 11-13 years (h (2) = 42-53%) and 14-16 years old (h (2) = 38-57%). Additive genetic and unique environmental influences for these three dimensions of schizotypal personality acted in part through a single common latent factor, with additional genetic effects specific to both Interpersonal-Affective and Disorganization subscales at each occasion. The longitudinal correlation between the latent schizotypy factor was r = 0.58, and genetic influences explained most of the stability in this latent factor over time (81%). These longitudinal data demonstrate significant genetic variance in schizotypal traits, with moderate stability between early to middle adolescence. In addition to common influences between the two assessments, there were new genetic and non-shared environmental effects that played a role at the later assessment, indicating significant change in schizotypal traits and their etiologies throughout adolescence.

Reappraisal of the interplay between psychosis and depression symptoms in the pathogenesis of psychotic syndromes: results from a twenty-year prospective community study

The interplay of psychotic and affective symptoms is a crucial challenge in understanding the pathogenesis of psychosis. In this study, we analyzed the interplay between two subclinical psychosis symptoms dimensions, and one depression symptoms dimension, using longitudinal data from Zurich. The Zurich study started in 1979 with a representative sample of 591 participants who were aged 20/21. Follow-up interviews were conducted at age 23, 28, 30, 35, and 41. The psychiatric symptoms were assessed with a semi-structured interview and the SCL 90-R. In this study, we analyzed three SCL-90-R subscales: the depression symptoms dimension and two distinct symptoms dimensions of subclinical psychosis, one representing a schizophrenia nuclear symptom dimension, the other representing a schizotypal symptoms dimension. Modeling was done with hybrid latent growth models, thereby including simultaneous and cross-lagged effects. The interplay between the two subclinical psychosis symptoms dimensions and the depression symptoms dimension includes several intertwined pathways. The schizotypal symptoms dimension has strong direct effects on the schizophrenia nuclear symptoms dimension, but also on the depression symptoms dimension. The latter has for its part an effect on the schizophrenia nuclear symptoms dimension. The main driving force within the dynamic interplay between depression and psychosis symptoms is a schizotypal symptoms dimension, which represents social and interpersonal deficiencies, ideas of reference, suspiciousness, paranoid ideation, and odd behavior. It does not only directly influence subclinical nuclear schizophrenia symptoms but also the symptoms of depression.

Sensitivity and specificity of the Chinese version of the Schizotypal Personality Questionnaire-Brief for identifying undergraduate students susceptible to psychosis

BACKGROUND

Early interventions can improve treatment outcomes for individuals with major psychiatric disorders and with nonspecific symptoms but increasingly impaired cognitive perception, emotions, and behaviour. One way used to identify people susceptible to psychosis is through the schizotypal personality trait. Persons with schizotypal characteristics have been identified with the widely used Schizotypal Personality Questionnaire-Brief. However, no suitable instruments are available to screen individuals in the Taiwanese population for evidence of early psychotic symptoms.

OBJECTIVES

The purpose of this study was to test the sensitivity and specificity of the Chinese version of the Schizotypal Personality Questionnaire-Brief for identifying undergraduate students' susceptibility to psychosis.

DESIGN

Two-stage, cross-sectional survey design.

SETTING AND PARTICIPANTS

The self-administered scale was tested in a convenience sample of 618 undergraduate students at a medical university in Taiwan. Among these students, 54 completed the scale 2 weeks apart for test-retest reliability, and 80 were tested to identify their susceptibility to psychosis.

DATA COLLECTION AND ANALYSIS

In Stage I, participants with scores in the top 6.5% were classified as the high-score group (n=40). The control group (n=40) was randomly selected from the remaining participants with scores <15 and matched by gender. These 80 students were asked to participate in psychiatric interviews in Stage II. The instrument was tested for reliability using intraclass correlation coefficients and the Kuder-Richardson formula 20. The instrument was analysed for optimal sensitivity and specificity using odds-ratio analysis and receiver operating characteristic curves.

RESULTS

The 22-item Chinese version of the Schizotypal Personality Questionnaire-Brief had a 2-week test-retest reliability of 0.82 and internal consistency of 0.76. The optimal cut-off score was 17, with odds ratios of 24.4 and an area under the receiver operating characteristic curves of 0.83. The instrument had a sensitivity of 80.0% and specificity of 85.9% in identifying undergraduate students' susceptibility to psychosis.

CONCLUSIONS

The Chinese version Schizotypal Personality Questionnaire-Brief is a reliable instrument, but should not be used as a screening tool until its psychometric properties have been evaluated in more detail. Other screening tools need to be used in future studies with the CSPQ-B to improve the accuracy of identifying susceptibility to psychosis among young adults.

Cluster A Personality Disorders: Schizotypal, Schizoid and Paranoid Personality Disorders in Childhood and Adolescence

Cluster A personality disorders (PD), including schizotypal personality disorder (SPD), paranoid personality disorder (PPD), and schizoid PD, are marked by odd and eccentric behaviors, and are grouped together because of common patterns in symptomatology as well as shared genetic and environmental risk factors. The DSM-IV-TR describes personality disorders as representing stable and enduring patterns of maladaptive traits, and much of what is understood about Cluster A personality disorders in particular stems from research with adult populations. Less in known about these disorders in children and adolescents, and controversy remains regarding diagnosis of personality disorders in general in youth. The current paper reviews the available research on Cluster A personality disorders in childhood and adolescence; specifically, we discuss differentiating between the three disorders and distinguishing them from other syndromes, measuring Cluster A disorders in youth, and the nature and course of these disorders throughout childhood and adolescence. We also present recent longitudinal data from a sample of adolescents diagnosed with Cluster A personality disorders from our research laboratory, and suggest directions for future research in this important but understudied area.

Neuroimaging predictors of transition to psychosis--a systematic review and meta-analysis

OBJECTIVES

In early stage psychosis research the identification of neurobiological correlates of vulnerability to schizophrenia is an important hurdle.

METHODS

We systematically reviewed the neuroimaging publications on high-risk subjects with subsequent transition to psychosis (HR-T) and conducted a meta-analysis calculating the effect size Cohen's d.

RESULTS

Out of 30 identified studies 25 met the inclusion criteria. Structural (s)MRI studies showed small to medium effect sizes of decreased prefrontal, cingulate, insular and cerebellar gray matter volume in HR-T compared to high-risk subjects without transition (HR-NT). Meta-analysis revealed relatively larger whole brain volumes in HR-T compared to HR-NT subjects (mean Cohen's d 0.36, 95% CI 0.27-0. 46). Compared to HR-NT, HR-T subjects showed in functional imaging studies reduced brain activation in prefrontal cortex, reduced neuronal density, and increased membrane turnover in frontal and cingulate cortex with medium to large effect sizes.

CONCLUSIONS

Despite methodological differences between studies, structural and neurochemical abnormalities in prefrontal, anterior cingulate, medial temporal and cerebellar cortex might be predictive for development of psychosis within HR subjects.

An examination of the factorial structure of the Schizotypal Personality Questionnaire-Brief (SPQ-B) among undergraduate students

Cognitive-perceptual, interpersonal, and disorganized subscales of the Schizotypal Personality Questionnaire-Brief (SPQ-B), reflecting the three commonly used subscales of the full-version SPQ, have been used in a number of studies. However, the factorial validity of SPQ-B subscales remains to be clarified. Utilizing data from 825 undergraduate students, confirmatory factor analyses involving the 22 items of the SPQ-B were conducted. A significant chi(2) difference test favored the 3-factor over the 1-factor model and fit indices for the 3-factor model were generally satisfactory. However, several of the items may index more than one of the hypothesized factors, so the item-factor separation is not sharp. Thus, more research is needed on the factorial validity of the increasingly used SPQ-B subscales.

Validity of the prodromal risk syndrome for first psychosis: findings from the North American Prodrome Longitudinal Study

Treatment and prevention studies over the past decade have enrolled patients believed to be at risk for future psychosis. These patients were considered at risk for psychosis by virtue of meeting research criteria derived from retrospective accounts of the psychosis prodrome. This study evaluated the diagnostic validity of the prospective "prodromal risk syndrome" construct. Patients assessed by the Structured Interview for Prodromal Syndromes as meeting criteria of prodromal syndromes (n = 377) from the North American Prodrome Longitudinal Study were compared with normal comparison (NC, n = 196), help-seeking comparison (HSC, n = 198), familial high-risk (FHR, n = 40), and schizotypal personality disorder (SPD, n = 49) groups. Comparisons were made on variables from cross-sectional demographic, symptom, functional, comorbid diagnostic, and family history domains of assessment as well as on follow-up outcome. Prodromal risk syndrome patients as a group were robustly distinguished from NC subjects across all domains and distinguished from HSC subjects and from FHR subjects on most measures in many of these domains. Adolescent and young adult SPD patients, while distinct from prodromal patients on definitional grounds, were similar to prodromals on multiple measures, consistent with SPD in young patients possibly being an independent risk syndrome for psychosis. The strong evidence of diagnostic validity for the prodromal risk syndrome for first psychosis raises the question of its evaluation for inclusion in Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition).

The effect of red light on backward masking in individuals with psychometrically defined schizotypy

INTRODUCTION

Previous research has suggested that individuals with schizophrenia and their relatives show a change in backward masking performance with a red background that is in the opposite qualitative direction as that found in nonpsychiatric controls. The present study examines this effect in individuals with psychometrically defined schizotypy to explore the potential of this effect to be a useful new qualitative endophenotype for schizophrenia-spectrum traits.

METHODS

The Abbreviated Youth Psychosis At-Risk Questionnaire was used to screen a large number of undergraduates for schizotypy symptoms. A sample of 23 participants scoring high on this measure were compared to a sample of 26 controls on a location backward masking task that was presented on both red and green backgrounds.

RESULTS

Consistent with findings in patients with schizophrenia, the participants reporting a high number of schizotypy features showed a decrease in performance to the red (compared to green) background and the controls showed a nonsignificant increase in performance--although this finding was limited to the stimulus-onset asynchrony (SOA) value that approximated the SOA with the largest effect size in the previous schizophrenia study (69 ms).

CONCLUSIONS

Although limited to one SOA, results extend earlier findings approximating this SOA to include a psychometrically defined schizotypy sample.

Psychometric properties of the Brief Version of the Schizotypal Personality Questionnaire in relatives of patients with schizophrenia-spectrum disorders and non-psychiatric controls

The Schizotypal Personality Questionnaire-Brief Version (SPQ-B), which includes cognitive-perceptual, interpersonal, and disorganized domains, was developed as a concise, self-report measure of schizotypy. This analysis was conducted to: (1) determine the internal consistency reliability of SPQ-B total and subscale scores, (2) use confirmatory factor analysis to assess the three-factor model as well as a single-factor solution, and (3) examine a measure of concurrent criterion validity of SPQ-B scores. The study was conducted at a large, urban, university-affiliated, public-sector health system in the southeastern United States. Data were obtained from 118 participants, including 61 biological relatives of patients with schizophrenia, schizoaffective disorder, or schizophreniform disorder, and 57 non-psychiatric controls. Relatives and controls did not differ significantly on SPQ-B total or subscale scores (or on the full 74-item SPQ total or subscale scores). Internal consistency reliability was adequate for the total SPQ-B score and the interpersonal subscale but was less than ideal for the cognitive-perceptual and disorganized subscales. Regarding the confirmatory factor analysis, though the three-factor solution yielded reasonably good fit to the data, the single-factor solution provided equal fit. Correlations between the three subscales ranged from .63 to .74. With regard to criterion validity, correlations between the SPQ-B total and subscale scores and schizotypy scores derived from a semi-structured, interview-based assessment revealed correlations generally ranging from .40 to .60. The SPQ-B may be a useful brief screening measure of schizotypy, though some limitations in its psychometric properties were evident in this sample. It may be advisable to use total SPQ-B scores rather than subscale scores in some situations, or to use factor analytic techniques to study the instrument's latent structure in specific samples.

Neurofunctional correlates of vulnerability to psychosis: a systematic review and meta-analysis

An understanding of the neurobiological correlates of vulnerability to psychosis is fundamental to research on schizophrenia. We systematically reviewed data from studies published from 1992 to 2006 on the neurocognitive correlates (as measured by fMRI) of increased vulnerability to psychosis. We also conducted a meta-analysis of abnormalities of activation in the prefrontal cortex (PFC) in high-risk and first episode subjects, and reviewed neuroimaging studies of high-risk subjects that used PET, SPECT and MRS. Twenty-four original fMRI papers were identified, most of which involved tasks that engaged the PFC. In fMRI studies, vulnerability to psychosis was associated with medium to large effect sizes when prefrontal activation was contrasted with that in controls. Relatives of patients affected with psychosis, the co-twins of patients and subjects with an At Risk Mental State (ARMS) appear to share similar neurocognitive abnormalities. Furthermore, these are qualitatively similar but less severe than those observed in the first episode of illness. These abnormalities have mainly been described in the prefrontal and anterior cingulated cortex, the basal ganglia, hippocampus and cerebellum.

Comparison of three computer-administered cognitive tasks as putative endophenotypes of schizophrenia

It has been repeatedly demonstrated that individuals with schizotypal personality features (SPF) exhibit similar endophenotypic traits as persons with schizophrenia. Less research has compared the relative sensitivity of different endophenotypes in the same sample of individuals with SPF. Fourteen university students with SPF (mean age 20.5+/-1.6; 43% male) and 26 controls (mean age 20.3+/-1.1; 31% male) were defined by the Abbreviated Schizotypal Personality Questionnaire (SPQ-B). All participants reported no known biological relative with schizophrenia. Participants completed three computer-administered cognitive tasks: a 6-min degraded-stimuli A-X Continuous Performance Test (CPT), the Wisconsin Card Sort Test (WCST), and a Span of Apprehension (SOA) task (6- and 12-letter arrays). On the CPT, only omission errors resulted in a statistically significant group difference, U=115.5, p=.05, Cohen's d=0.54 (medium effect size), with the SPF group (mean errors: 3.43+/-3.28) making more omission errors than controls (mean errors: 1.88+/-2.66). Notably, 46% of the controls had no omission errors, compared to 14% of the SPF group. The only SPQ-B factor score to show a statistically significant linear relationship with CPT omission errors was the Cognitive-Perceptual factor (rs=.33, p=.04). Group differences on performance indices from the SOA and WCST did not approach statistical significance. Based on performance from the community-identified schizotypes, results suggest that performance on the CPT may represent a more robust endophenotype of schizophrenia, compared to the SOA and WCST.