Schizotypal dimensions in normals and schizophrenic patients: a comparison with other clinical samples

Cue-Reactive Phenomenology Mediates the Relationship Between Positive Schizotypy and Cue-Reactive Urge to Gamble in Poker-Machine Gamblers

Although ubiquitous in numerous nightlife cultures, poker-machines present a high risk for problematic use and addiction. Previous research has demonstrated that gambling cues (e.g., flashing lights) can activate gambling urges in poker-machine gamblers. However, the processes that contribute to the maintenance of cue-reactive urges to gamble remain unclear. Consequently, the present study explored whether positive schizotypy predicted gambling urge, and whether cue-reactive altered state of awareness, cue-reactive altered time sense, and cue-reactive absorption mediated this relationship. Seventy adults aged between 19 and 68 (M = 48.86, SD = 12.82) participated in an online cue-reactivity experiment. Participants first completed the Problem Gambling Severity Index and the Unusual Experiences subscale of the Short Oxford-Liverpool Inventory of Feelings and Experiences. Subsequently, at three time points (i.e., baseline, directly after a neutral cue, and directly after a gambling cue) participants completed the Altered State of Awareness, Altered Time Sense, and Absorption subscales of the Phenomenology of Consciousness Inventory and a visual analogue scale measuring cue-reactive urge to gamble. It was found that positive schizotypy was significantly positively correlated with cue-reactive urge to gamble. Additionally, cue-reactive altered state of awareness, cue-reactive altered time sense, and cue-reactive absorption mediated this relationship. The theoretical, clinical and practical implications are discussed.

Quantifying the effects of practicing a semantic task according to subclinical schizotypy

The learning ability of individuals within the schizophrenia spectrum is crucial for their psychosocial rehabilitation. When selecting a treatment, it is thus essential to consider the impact of medications on practice effects, an important type of learning ability. To achieve this end goal, a pre-treatment test has to be developed and tested in healthy participants first. This is the aim of the current work, which takes advantage of the schizotypal traits present in these participants to preliminary assess the test's validity for use among patients. In this study, 47 healthy participants completed the Schizotypal Personality Questionnaire (SPQ) and performed a semantic categorization task twice, with a 1.5-hour gap between sessions. Practice was found to reduce reaction times (RTs) in both low- and high-SPQ scorers. Additionally, practice decreased the amplitudes of the N400 event-related brain potentials elicited by semantically matching words in low SPQ scorers only, which shows the sensitivity of the task to schizotypy. Across the two sessions, both RTs and N400 amplitudes had good test-retest reliability. This task could thus be a valuable tool. Ongoing studies are currently evaluating the impact of fully deceptive placebos and of real antipsychotic medications on these practice effects. This round of research should subsequently assist psychiatrists in making informed decisions about selecting the most suitable medication for the psychosocial rehabilitation of a patient.

Finding normal-to-better neurocognitive indexes in individuals with schizotypal traits using a social role task

Schizophrenia patients make more errors and have longer reaction times (RTs) than healthy controls in most cognitive tasks. Deficits are also observed in subclinical participants having high scores on the schizotypal personality questionnaire (SPQ). They are accompanied by smaller amplitudes of the event-related brain potentials (ERPs) that index attention and semantic- and working-memory. These functions are thus thought to be impaired in individuals having various schizophrenia attributes (SzAs). Nevertheless, normal RTs were recently found in SzAs during a particular self-referential task where half of the stimuli were names of extraordinary social roles (e.g., genius). Each name (ordinary or extraordinary) was presented individually, and participants were asked to decide whether or not they would consider themselves performing the role at any moment of their lives. To further test an absence of cognitive deficits in this task, the ERPs elicited by names of social roles were also examined in 175 healthy participants. The absence of longer RTs in high- than in low-SPQs was replicated. Moreover, the ERPs of high SPQs had larger occipital N1s, larger P2s and larger occipital N400s than those of low SPQs while late positive potentials (LPPs) were of similar amplitudes. Such results are consistent with clinical observations of greater attention and faster processing of stimuli related to extraordinary/delusional beliefs. Further studies should test whether the cognitive deficits found in SzAs are due to the use of tasks and stimuli that are less within their focus of interest than within that of healthy controls.

The positive dimension of schizotypy is associated with a reduced attenuation and precision of self-generated touch

The brain predicts the sensory consequences of our movements and uses these predictions to attenuate the perception of self-generated sensations. Accordingly, self-generated touch feels weaker than an externally generated touch of identical intensity. In schizophrenia, this somatosensory attenuation is substantially reduced, suggesting that patients with positive symptoms fail to accurately predict and process self-generated touch. If an impaired prediction underlies the positive symptoms of schizophrenia, then a similar impairment should exist in healthy nonclinical individuals with high positive schizotypal traits. One hundred healthy participants (53 female), assessed for schizotypal traits, underwent a well-established psychophysics force discrimination task to quantify how they perceived self-generated and externally generated touch. The perceived intensity of tactile stimuli delivered to their left index finger (magnitude) and the ability to discriminate the stimuli (precision) was measured. We observed that higher positive schizotypal traits were associated with reduced somatosensory attenuation and poorer somatosensory precision of self-generated touch, both when treating schizotypy as a continuous or categorical variable. These effects were specific to positive schizotypy and were not observed for the negative or disorganized dimensions of schizotypy. The results suggest that positive schizotypal traits are associated with a reduced ability to predict and process self-generated touch. Given that the positive dimension of schizotypy represents the analogue of positive psychotic symptoms of schizophrenia, deficits in processing self-generated tactile information could indicate increased liability to schizophrenia.

Cumulative sociodemographic disadvantage partially mediates associations between childhood trauma and schizotypy

OBJECTIVES

Risk for psychosis in the general population is characterized by a set of multidimensional traits that are referred to as schizotypy. Higher levels of schizotypy are associated with socioeconomic disadvantage and childhood trauma, just as these risk factors are associated with schizophrenia and bipolar disorder. Here, we set out to investigate whether cumulative sociodemographic disadvantage mediates associations between childhood trauma and schizotypy in adulthood.

METHODS

A sociodemographic cumulative risk (SDCR) score was derived from six risk indices spanning employment, education, income, socioeconomic status, marital, and living circumstances for 197 participants that included both healthy (n = 57) and clinical samples with schizophrenia or schizoaffective disorder (n = 65) or bipolar disorder (n = 75). A series of multiple linear regressions was used to examine the direct and indirect associations among childhood trauma (measured with the Childhood Trauma Questionnaire), the SDCR index, and levels of schizotypy (measured with the Schizotypal Personality Questionnaire).

RESULTS

Schizotypy was independently associated with trauma and the SDCR index. In addition, the SDCR index partially mediated associations between trauma and schizotypy.

CONCLUSIONS

These findings in a mixed sample of healthy and clinical participants represent the full spectrum of schizotypy across health and illness and suggest that effects of childhood trauma on schizotypal personality organization may operate via cumulative socioeconomic disadvantage in adulthood.

PRACTITIONER POINTS

The strong associations between trauma and schizotypy suggest that systematic health screening of children exposed to early life trauma may assist to identify those at risk of developing psychosis. Clinicians should pay attention to various indicators of sociodemographic disadvantage in patients prone to psychosis, in addition to any exposure to trauma during childhood.

Schizotypal personality disorder in clinical obsessive-compulsive disorder samples: a brief overview

Obsessive-compulsive disorder (OCD) is a chronic and disabling mental disorder characterized by the presence of obsessions and/or compulsions that cause major distress and impair important areas of functioning. About 9 out of 10 patients with OCD have comorbid psychiatric diagnoses. A high proportion of clinically diagnosed OCD patients fulfill diagnostic criteria of a schizophrenia spectrum disorder, to the point that significant evidence in the literature supports the existence and the clinical relevance of a schizo-obsessive spectrum of disorders, including schizotypal personality disorder (SPD) with OCD (schizotypal OCD). In this paper, we provide a brief but comprehensive analysis of the literature on the clinical coexistence between OCD and SPD. The clinical validity of the so-called schizotypal OCD is analyzed through a comprehensive investigation of the relationship between SPD features and obsessive-compulsive phenomena in clinical OCD samples. This review describes the potential connections between OCD and SPD on the epidemiological, sociodemographic, psychopathological, and clinical levels. SPD is commonly observed in OCD patients: about 10% of OCD patients have a full categorical diagnosis of SPD. Early clinical identification of SPD features-and, more generally, of psychotic features and personality disorders-in OCD patients is strongly recommended. In fact, a proper and early diagnosis with early treatment may have benefits for prognosis. However, although schizotypal OCD seems to have clinical and predictive validity, further neurobiological and genetic studies on etiological specificity are warranted.

Bifactor Structure of the Schizotypal Personality Questionnaire Across the Schizotypy Spectrum

Despite widespread use in schizophrenia-spectrum research, uncertainty remains around an empirically supported and theoretically meaningful factor structure of the Schizotypal Personality Questionnaire (SPQ). Current identified structures are limited by reliance on exclusively nonclinical samples. The current study compared factor structures of the SPQ in a sample of 335 nonpsychiatric individuals, 292 schizotypy-spectrum individuals (schizophrenia, schizoaffective disorder, or schizotypal personality disorder), and the combined group (N = 627). Unidimensional, correlated, and hierarchical models were assessed in addition to a bifactor model, wherein subscales load simultaneously onto a general factor and a specific factor. The best-fitting model across samples was a two-specific factor bifactor model, consistent with the nine symptom dimensions of schizotypy as primarily a direct manifestation of a unitary construct. Such findings, for the first time demonstrated in a clinical sample, have broad implications for transdiagnostic approaches, including reifying schizotypy as a construct underlying diverse manifestations of phenomenology across a wide range of severity.

The network structure of schizotypy in the general population

Schizotypal personality traits show similarity with schizophrenia at various levels of analysis. It is generally agreed that schizotypal personality is multidimensional; however, it is still debated whether impulsive nonconformity should be incorporated into theories and measurement of schizotypy. In addition, relatively little is known about the network structure of the four-dimensional model of schizotypal personality. To estimate the network structure of schizotypy, we used data from participants recruited from the community (N = 11,807) who completed the short version of the Oxford-Liverpool Inventory of Feelings and Experiences, a widespread self-report instrument that assesses the positive, negative, disorganised and impulsive domains of schizotypy. We performed community detection, then examined differences between communities in terms of centralities and compared the strength of edges within and between communities. We found communities that almost perfectly corresponded to the a priori-defined subscales (93% overlap, normalised mutual information = 0.74). Items in the disorganisation community had higher closeness centrality relative to items in the other communities (Cliff's Δs ranged from 0.55 to 0.83) and weights of edges within the disorganisation community were stronger as compared to the negative schizotypy and impulsive nonconformity communities (Cliff's Δs = 0.33). Our findings imply that the inclusion of impulsive nonconformity items does not dilute the classical three-factor structure of positive, negative and disorganised schizotypy. The high closeness centrality of disorganisation concurs with theories positing that cognitive slippage and associative loosening are core features of the schizophrenic phenotype.

Preserved intention understanding during moral judgments in schizophrenia

INTRODUCTION

Although there is convincing evidence for socio-cognitive impairments in schizophrenia spectrum disorder (SSD), little evidence is found for deficient moral cognition. We investigated whether patients with SSD showed altered moral judgments in a story task where the protagonist either had a neutral or malicious intention towards another person. This paradigm examined whether SSD relates to altered moral cognition in general or specifically to impaired integration of prior information (such as beliefs) in moral judgments.

METHODS

23 patients and 32 healthy controls read vignettes created in a 2 x 2 design. The protagonist in each story either had a neutral or negative intention towards another person which, as a result, either died (negative outcome) or did not die (neutral outcome). Participants rated the moral permissibility of the protagonist's action. Standard null hypothesis significance testing and equivalent Bayes analyses are reported.

RESULTS

Schizophrenia patients did not differ significantly in permissibility ratings from healthy controls. This finding was supported by the Bayes analyses which favoured the null hypothesis. Task performance was not related to symptom severity or medication.

CONCLUSIONS

The current findings do not support the notion that moral judgments are deficient in schizophrenia. Furthermore, the current study shows that patients do not have observable difficulties in integrating the protagonist's belief in the rating of the moral permissibility of the action-outcome.

Quality of life in Klinefelter patients on testosterone replacement therapy compared to healthy controls: an observational study on the impact of psychological distress, personality traits, and coping strategies

PURPOSE

We aimed to verify if 1 year-testosterone-replacement therapy could produce a psychopathological recovery and a satisfactory quality of life in Klinefelter syndrome (KS) patients compared to matched healthy controls. Further, we analyzed personality traits and coping strategies, an issue not yet examined in androgen-treated KS patients. We also enquired whether any of the sociodemographic and psychological variables might predict a patient's general and sexual life satisfaction.

METHODS

The Quality of Life Enjoyment and Satisfaction Questionnaire and the Temperament and Character Inventory-Revised were administered to both 23 KS patients and matched healthy subjects. Psychopathology was investigated by the Symptom Checklist-90-Revised (SCL-90-R) and the Mini-mental State Examination. The COPE Inventory was used to identify cognitive and behavioral strategies to manage disease-related distress.

RESULTS

In testosterone-treated KS patients, when compared with controls, SCL-90-R subscales analysis evidenced high psychological distress, mainly presented as obsessive thoughts, hanger-hostility, phobias, and psychoticism. Self-directedness and self-transcendence, along with the prevalent use of emotion-focused coping strategies, outlined the personality of our KS patients. Depression and somatization proved to be predictors of general life dissatisfaction. Depression, anger-hostility, and paranoid ideation, instead, emerged as predictors of sexual life dissatisfaction.

CONCLUSION

Endocrinologists should cooperate with mental health providers to foster a better outcome of the disease in KS patients.

Cognitive-perceptual and disorganized schizotypal traits are nonlinearly related to atypical semantic content on tasks of semantic fluency

Language deficits emerge early in the course of schizophrenia, yet research findings in those at-risk for schizophrenia, such as those with schizotypy, are mixed. The purpose of the present study was to elucidate the relationship of language ability, measured via semantic fluency, to schizotypy, examining both linear and non-linear relations. Semantic fluency data from 295 individuals with varying amounts of schizotypal traits were analyzed utilizing traditional methods (i.e., counting words generated that fit a specific semantic category). The content of semantic fluency responses was also analyzed via a semantic infrequency score (i.e., how infrequent participant responses were relative to all responses generated for the category in the study sample) and a total semantic productivity score (i.e., how many unique words generated overall, including those that did not fit the semantic category). Using traditional methods of scoring, schizotypy was not related to semantic fluency. However, schizotypy was non-linearly related to semantic infrequency and productivity, reflecting atypical semantic activation and processing. In particular, cognitive-perceptual and disorganized, but not interpersonal, traits were related to semantic infrequency and productivity. Valuable content-based information is missed when only analyzing semantic fluency data via the traditional method in the schizophrenia spectrum population. Cognitive-perceptual and disorganized traits, attenuated thought disorder symptoms, evidence the strongest relationship to semantic fluency, further illustrating the link between language and schizophrenia symptoms along the schizophrenia spectrum.

Schizotypy and individual differences in peripersonal space plasticity

The space surrounding our body, defined as peripersonal space (PPS), is dynamically shaped by our motor experiences. For instance, PPS extends after using a tool to reach far objects. Several studies have demonstrated how PPS size varies across people, depending on different individual characteristics, including schizotypy. Coherently, narrower PPS boundaries have been reported among high schizotypal individuals and schizophrenia patients. However, little is known about the relationship between PPS plasticity and personality traits like schizotypy. To this purpose, the present study has investigated the individual PPS plasticity, after two different motor trainings, along the schizotypal continuum. Specifically, PPS plasticity was tested after using a tool (Experiment 1) and after the mere observation of another person using the same tool (Experiment 2). Indeed, previous evidence has shown that tool-use observation influences visual distance judgments, extending the representation of PPS. To date, however, there is no study investigating whether observation of tools action could also affect multisensory PPS tasks. Experiment 1 has shown that PPS boundaries extended after using the tool; on the other hand, Experiment 2 has revealed the absence of PPS expansion. Moreover, greater PPS expansion emerged in the relatively-low schizotypal group than in the relatively-high one, regardless of the type of motor training performed. The absence of PPS modulation after the observation task is discussed in relation to recent findings showing that intentional action and/or the goal of the action represent potentially crucial elements to trigger PPS plasticity. Finally, these new results extend previous evidence underlining a potential general functional alteration of PPS with the increase of schizotypal level.

Adding a Dimension to the Dichotomy: Affective Processes Are Implicated in the Relationship Between Autistic and Schizotypal Traits

INTRODUCTION

There is a recognized increase in vulnerability to psychosis in autistic people (AP). However, the construct of psychosis (particularly schizophrenia) contains several distinct factors, making understanding the relationship between autism and psychosis complex. Previous research has suggested that affective lability may be particularly related to psychotic experiences for AP who have experienced psychosis (AP-P). There is also a suggestion that psychosis might be a state of extreme (over)empathizing, perhaps related to emotional processes.

METHOD

We recruited three groups: AP-P (N = 23), a group of AP who had not experienced psychosis (AP-NP; N = 59) and a neurotypical control group (NC, N = 41). Participants completed measures of autistic traits, schizotypal traits (as a proxy for psychosis-proneness), emotional processes, and perspective taking (as a proxy for the type of empathizing most theoretically likely to be linked to psychosis). As well as comparisons between groups, regression analyses were used to understand the influence of dependent variables on schizotypal traits.

RESULTS

We found that AP-P had significantly higher rates of schizotypy (positive and disorganized), as well as higher rates of emotional difficulties. Across all groups, affective lability had a positive and significant association with positive and disorganized schizotypal traits. Differences in perspective taking between groups were small and generally non-significant, particularly in adjusted comparisons; additionally, its impact on schizotypy was small and non-significant.

DISCUSSION

Our findings suggest that positive and disorganized schizotypy, in particular, have a relationship with affective lability. This, in turn, supports the idea of emotional processes as related to the development of schizotypal traits and psychosis across all individuals, regardless of autism diagnostic status. We found no evidence of empathy relating to any subscale of schizotypy, or the total schizotypy score. We contend that emotional processes should be considered in exploration of the relationship between autism and schizotypy in future. This may help to explain some of the findings of overlap between these constructs in previous research. Factors known to affect neurodevelopment of emotion systems such as history of early trauma, challenges during pregnancy and birth, and early childhood experiences of adversity during critical windows of development need further consideration in future research.

Personality traits across the psychosis spectrum: A Hierarchical Taxonomy of Psychopathology conceptualization of clinical symptomatology

Psychotic disorders have varied clinical presentations, diagnostic stability is poor and other mental disorders often co-occur with the conditions. To improve the clinical and pathophysiological utility of classification systems for psychosis, it is necessary to consider how symptoms may reflect dimensions of psychopathology that extend beyond the boundaries of traditional diagnostic classifications. We examined personality deviation as a means for explaining symptom variation across individuals with serious mental illness. Participants (N = 312) with psychosis, first-degree biological relatives and healthy controls underwent comprehensive clinical evaluations that included symptom ratings and Diagnostic Statistical Manual consensus diagnoses. They completed the Personality Inventory for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (PID-5), which provides multidimensional assessment of personality disturbances and characterizes psychosis-relevant phenomena, and the Schizotypal Personality Questionnaire (SPQ), a widely accepted measure of schizotypal traits. PID-5 was comparable with SPQ in differentiating between participants with and without psychosis. Greater psychotic symptomatology and higher scores on the SPQ Cognitive-perceptual dimension were associated with higher scores on PID-5 Psychoticism. Facet-level traits showed diverse associations with existing clinical syndromes, suggesting they have utility for quantifying separable symptom dimensions that cut across existing disorders. Yet the patient groups were similar across four of the five PID-5 personality trait domains, indicating shared patterns of personality expression that challenge existing categorical delineations. © 2019 John Wiley & Sons, Ltd.

Relationships between intra-individual variability and subclinical psychosis

Extensive research indicates that elevated intra-individual variability (IIV) of reaction time is associated with subclinical psychosis, as well as clinically diagnosed psychotic disorder. However, findings regarding the details of this relationship are equivocal. In particular, it is unknown whether associations between elevated IIV and subclinical psychosis are specific to certain psychotic symptoms or to complex reaction time tasks. Data from 492 undergraduates from the University of Otago were used to address this issue. Schizotypy and psychotic-like experiences (PLE) were assessed via interview and questionnaire, and participants completed both a simple reaction time (SRT) task and a continuous performance task-identical pairs version (CPT-IP). The individual standard deviation and coefficient of variation (ICV) were used as measures of IIV. Participants reporting PLE were more likely to have elevated ICV on the CPT-IP. These associations were specific to paranoid psychotic experiences, and to the suspiciousness subscale of the Schizotypal Personality Questionnaire. There were also weak associations between SRT ICV and PLE. The inclusion of a battery of reaction time tasks assessing different aspects of cognitive control is suggested for future research, and the findings are discussed in relation to theoretical approaches to paranoia and delusions.

Schizotypy and smooth pursuit eye movements as potential endophenotypes of obsessive-compulsive disorder

Patients with obsessive-compulsive disorder (OCD) show dysfunctions of the fronto-striatal circuitry, which imply corresponding oculomotor deficits including smooth pursuit eye movements (SPEM). However, evidence for a deficit in SPEM is inconclusive, with some studies reporting reduced velocity gain while others did not find any SPEM dysfunctions in OCD patients. Interestingly, psychosis-like traits have repeatedly been linked to both OCD and impaired SPEM. Here, we examined a large sample of n = 168 patients with OCD, n = 93 unaffected first-degree relatives and n = 171 healthy control subjects to investigate whether elevated levels of schizotypy and SPEM deficits represent potential endophenotypes of OCD. We applied a SPEM task with high demands on predictive pursuit that is more sensitive to assess executive dysfunctions than a standard task with continuous visual feedback, as episodes of target blanking put increased demands on basal ganglia and prefrontal involvement. Additionally, we examined the relation between schizotypy and SPEM performance in OCD patients and their relatives. Results indicate that OCD patients and unaffected relatives do not show deficient performance in either standard or predictive SPEM. Yet, both patients and relatives exhibited elevated levels of schizotypy, and schizotypy was significantly correlated with velocity gain during standard trials in unmedicated and depression-free OCD patients. These findings highlight the role of schizotypy as a candidate endophenotype of OCD and add to the growing evidence for predisposing personality traits in OCD. Furthermore, intact gain may represent a key characteristic that distinguishes the OCD and schizophrenia patient populations.

A reassessment of the higher-order factor structure of the German Schizotypal Personality Questionnaire (SPQ-G) in German-speaking adults

The Schizotypal Personality Questionnaire (SPQ) is a widely-used self-report instrument for the assessment of schizotypal personality traits. However, the factor structure of scores on English and non-English translations of the SPQ has been a matter of debate. With little previous factorial evaluation of the German version of the SPQ (SPQ-G), we re-assessed the higher-order factor structure of the measure. A total of 2,428 German-speaking adults from Central Europe (CE) and the United Kingdom (UK) completed the SPQ-G. Confirmatory factor analysis - testing proposed 2-, 3-, and 4-factor models of SPQ-G scores - indicated that the 4-factor solution had best fit. Partial measurement invariance across cultural group (CE and UK) and sex was obtained for the 4-factor model. Further analyses showed CE participants had significantly higher scores than UK participants on one schizotypal facet. These results suggest that scores on the SPQ-G are best explained in terms of a higher-order, 4-factor solution in German migrant and non-migrant adults.

Dimensional Traits of Schizotypy Associated With Glycine Receptor GLRA1 Polymorphism: An Exploratory Candidate-Gene Association Study

Schizotypy captures the underlying genetic vulnerability to schizophrenia. However, the genetic underpinnings of schizotypy remain unexplored. The authors examined the relationship between single nucleotide poly-morphisms (SNPs) and schizotypy. A sample of 137 subjects (43 healthy controls, 34 subjects with schizotypal personality disorder [SPD], 32 with borderline personality disorder, and 25 with other personality disorders) completed the Schizotypal Personality Questionnaire (SPQ). Subjects were genotyped using a custom array chip. Principal component analysis was used to cluster SPQ variables. Linear regression tested for associations between dimensional schizotypy and SNPs. Logistic regression tested for associations between SNPs and SPD diagnosis. There were significant associations between the minor alleles of three SNPs within the glycine receptor alpha 1 subunit (GLRA1) and the disorganized schizotypy dimension, even after Bonferroni correction. There were no significant associations between any SNPs and the categorical SPD diagnosis. Glycine receptor pathways may have an impact on dimensional traits of psychosis.

Schizotypal traits and forearm motor control against self-other produced action in a bimanual unloading task

The present study investigated the relation between schizotypy and motor control against self- or other-produced action. We used an unloading task to focus on the timing component of anticipatory motor control. In the task, a weight was removed from a participants' hand by the participants themselves or by an experimenter (voluntary versus imposed unloading). Postural disturbance at the removal timing was measured as an index of predictive function in motor control. We hypothesized that the postural disturbance in the voluntary unloading would be positively related to schizotypal traits; however, the results did not support this theory. The results showed almost zero correlation between the schizotypy scores and the postural disturbance in the voluntary unloading condition. In contrast, the schizotypy scores positively correlated with the postural disturbance in the imposed unloading condition. These findings were replicated across two participant groups and two schizotypy scales. Further analyses on subscales of the schizotypy questionnaire found moderate levels of positive correlation between each subscale for Cognitive-Perceptual and Disorganization factors and the disturbance. Accordingly, the present study did not support the idea that non-pathological individuals with high schizotypal traits have deficits in prediction of self-produced actions, at least for a temporal domain. Instead, the results suggested that individuals with high schizotypal traits, particularly for the positive and disorganization symptoms, are not good at responding to others-produced actions. The schizophrenic symptoms were discussed in terms of the failure in the processes executed after calculating prediction of sensory consequences and dysfunction in internal models for "other people".

Stress induced cortisol release and schizotypy

Cortisol is involved in preparing the body's response for stress. However, in those at risk for mental health problems, abnormal cortisol release following stress has been reported. In particular, we are yet to fully understand how stress leads to an exacerbation of symptoms and progression of risk in those who express psychosis proneness or schizotypy. Using the Trier Social Stress Test, we examined the effect of experimentally induced psychosocial stress on cortisol release in otherwise healthy individuals with schizotypal traits. This cross-sectional study included 58 individuals (32.76% male, mean age 22.43). Schizotypy was assessed by total Schizotypal Personality Questionnaire score and we additionally captured ratings of subjective stress. Salivary cortisol was collected over six time points spread prior to and after stress induction and was available for analysis in 39 individuals (28.21% male, mean age 22.77). Those with high schizotypal traits exhibited higher baseline cortisol levels (5.18 nmoL vs 3.71 nmoL). However, those with high schizotypal traits also displayed reduced mean cortisol release (2.02 nmoL vs 5.11 nmoL) and had a delayed cortisol release peak following psychosocial stress. These results indicate those with high schizotypal traits do not display physiological readiness following psychosocial stressors, perhaps due to an already taxed stress system.

Psychometric properties of the Malay Schizotypal Personality Questionnaire: Measurement invariance and latent mean comparisons in Malaysian adults

INTRODUCTION

The Schizotypal Personality Questionnaire (SPQ) is a widely used self-report measurement instrument for the assessment of schizotypal personality traits. However, the factor structure of the SPQ has been a matter of some debate. As a contribution to this debate, we examined the factor structure of the SPQ in Malaysian adults.

METHOD

A total of 382 Malaysian adults completed a Malay translation of the SPQ. Confirmatory factory analysis was used to examine the fit of 3- and 4-factor solutions for the higher-order dimensionality of the SPQ. Ethnic invariance for the best-fitting model was tested at the configural, metric, and scalar levels, and a multivariate analysis of variance was used to examine sex and ethnicity differences in domain scores.

RESULTS

The 4-factor model provided a better fit to the data than did the 3-factor model. The 4-factor model also demonstrated partial measurement invariance across ethnic groups. Latent mean comparisons for sex and ethnicity revealed a number of significant differences for both factors, but effect sizes were small.

DISCUSSION

The 4-factor structure of the SPQ received confirmatory support and can be used in Malay-speaking populations.

Developmental Aspects of Schizotypy and Suspiciousness: a Review

Purpose of the Review

This review identifies the early developmental processes that contribute to schizotypy and suspiciousness in adolescence and adulthood. It includes the most recent literature on these phenomena in childhood.

Recent Findings

The early developmental processes that affect schizotypy and paranoia in later life are complex. In contrast to existing studies of psychiatric patients and clinical/nonclinical adult populations, the study of schizotypy and suspiciousness in young children and adolescents is possible due to new child-appropriate dimensional assessments. New assessments and the advancement of technology (e.g., virtual reality in mental health) as well as statistical modeling (e.g., mediation and latent-class analyses) in large data have helped identified the developmental aspects (e.g., psychosocial, neurocognitive and brain factors, nutrition, and childhood correlates) that predict schizotypy and suspiciousness in later life.

Summary

Prospective longitudinal designs in community youths can enhance our understanding of the etiology of schizophrenia-spectrum disorders and, in the future, the development of preventive interventions by extending adult theories and interventions to younger populations.

Psychotic-spectrum symptoms, cumulative adversity exposure and substance use among high-risk girls

AIM

Psychotic-spectrum symptoms are linked to trauma, substance/alcohol use (SAU), criminality/violence and poor functional outcomes, supporting the need for early detection in vulnerable populations. To better understand high-risk girls' mental health, we assessed: (1) psychotic-spectrum symptoms; (2) cumulative trauma, adversity and loss exposures (C-TALE) and adversity-indicators (symptoms, maladaptive coping, stressor-reactivity); and SAU risk-factors; and (3) relationships among psychotic-spectrum symptoms, adversity-indicators and SAU risk-factors.

METHODS

We administered the Structured Clinical Interviews for Psychotic Spectrum, and Trauma and Loss Spectrum to 158 adolescent delinquent girls.

RESULTS

Girls' psychotic-spectrum profiles were similar to previously reported adult psychotic patients and characterized by typical symptoms (hallucinations/delusions, reported largely SAU-independent), interpersonal sensitivity, schizoid traits and paranoia (over-interpretation, anger over-reactivity, hypervigilance). Auditory/visual hallucinations (55.7%), delusions (92.4%), ideas of reference (96.8%) and adversity (90.0% ≥10/24 C-TALE-types) were common. Mean loss (4) and trauma (8) onset-age occurred before SAU-onset (12). Significant positive correlations were found among psychotic-spectrum symptoms, stressor-reactivity, C-TALE, adversity-indicators; and number of SAU-types; and a negative correlation occurred between psychotic-spectrum symptoms and earlier alcohol use onset. After controlling for number of SAU-types, stressor-reactivity and adversity-related numbing individually had the largest associations with total psychotic-spectrum symptoms (b = 2.6-4.3). Girls averaged more than 4 maladaptive coping strategies (e.g., 24.8% attempted suicide) in response to adversity, amplifying potential health-disparities. No racial/ethnic differences emerged on psychotic-spectrum symptoms.

CONCLUSIONS

This symptom constellation during adolescence likely interferes with social and academic functioning. Whether representing a prodromal phase, trauma-response or cross-diagnostic psychopathology, accurate early detection and appropriate treatment of psychotic-spectrum symptoms are warranted to improve functional outcomes in vulnerable populations.

The Factor Structure of the Schizotypal Personality Questionnaire in Undergraduate and Community Samples

The prevailing theoretical model of the Schizotypal Personality Questionnaire (SPQ) is a three-factor model based on subscale-level analyses. However, recent item-level factor analyses of the SPQ suggest a four- or five-factor model. To examine the factor structure of the SPQ and how this structure may differ between undergraduate and community samples, the authors conducted exploratory and confirmatory item-level factor analyses of this measure on undergraduate (N = 1,850) and community participants (N = 1,464). A clear three-factor solution was found in the community sample, whereas a somewhat equivocal four-factor solution was found in the undergraduate sample. Both structures displayed gender invariance. This is the first study to address the issues of undergraduate sample generalizability and gender invariance in an item-level exploratory factor analysis of the SPQ. Given the disparate findings in the samples, this study indicates the importance of using both community and undergraduate samples when examining the factor structure of the SPQ.

Associations of differential schizotypal dimensions with executive working memory: A moderated-mediation analysis

BACKGROUND

Increased schizotypal traits are observed in a percentage of the general population and in the schizophrenia-spectrum and have been associated with impairments in working memory. In this study we examined the effects of four schizotypal dimensions [Negative (NegS), Paranoid (ParS), Cognitive-Perceptual (CPS), Disorganized (DiS)] on executive working memory (EWM), as mediated by set-shifting, planning and control inhibition. We also examined whether these associations are moderated by family-history of psychosis.

METHODS

Our sample consisted of 110 unaffected first-degree relatives of schizophrenia-spectrum patients and 120 control individuals. Schizotypy was assessed with the Schizotypal Personality Questionnaire. Participants were also tested with the Letter-Number Sequencing, Wisconsin Card Sorting, Stroop Color-Word and Stockings of Cambridge tasks. The effects of set-shifting, control inhibition and planning on the relationship between schizotypy and EWM were examined with mediation analyses. Moderated-mediation analyses examined potential moderating effects of group membership (unaffected relative/community participant).

RESULTS

All mediators were significant in the relationship between NegS and EWM. The effects of ParS were mediated only by set-shifting and planning. Planning and control inhibition were the only significant mediators on the effects of CPS and DiS on EWM, respectively. The moderated-mediation analyses revealed that these findings apply only in the community group.

CONCLUSIONS

We found that the effects of different schizotypal dimensions on EWM are mediated by other cognitive processes in individuals without personal/family history of psychosis. This is probably due to either more severe impairments in the cognitive processes of the relatives or restrictions in our sample and study-design.

Chinese version of the Schizotypal Personality Questionnaire: Factor structure replication and invariance across sex

INTRODUCTION

The Schizotypal Personality Questionnaire (SPQ) is a self-report measure assessing symptoms of schizotypy. The SPQ has been used in both normative and clinical samples and has much theoretical and empirical support. A three-factor structure of the SPQ, derived on the basis of work in schizophrenia, consisting of Cognitive-Perceptual, Interpersonal, and Disorganized factors, has been well replicated. The present study aimed to (i) validate this three-factor structure in the Chinese version of the SPQ in a sample of individuals of Chinese ethnicity, and (ii) test for invariance across sex.

METHODS

A total of 209 (99 males) undergraduate university students (Mage  = 19.5, SD = 1.6) were administered the SPQ.

RESULTS

Confirmatory factor analysis indicated a better fit between the data and the three-factor model compared with a one-factor model. Multigroup confirmatory factor analysis also found strong measurement invariance across sex.

DISCUSSION

The current results add to a growing body of literature evidencing cross-cultural validity of the SPQ and its invariance across sex. Research and clinical implications of the current results are discussed.

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.

An autistic dimension

This article focuses on the possibility that autism spectrum disorder (ASD: Asperger syndrome, autism and atypical autism) in its milder forms may be clinically important among a substantial proportion of patients with obsessive-compulsive disorder (OCD), and discusses OCD subtypes based on this proposition. The hypothesis derives from extensive clinical experience of OCD and ASD, and literature searches on MEDLINE. Neuropsychological deficits are more common in OCD than in panic disorder and depression. Moreover, obsessive-compulsive and schizotypal personality disorders are over-represented in OCD. These may constitute misperceived clinical manifestations of ASD. Furthermore, repetitive behaviours and hoarding are common in Asperger syndrome. It is suggested that the comorbidity results in a more severe and treatment resistant form of OCD. OCD with comorbid ASD should be recognized as a valid OCD subtype, analogous to OCD with comorbid tics. An odd personality, with paranoid, schizotypal, avoidant or obsessive-compulsive traits, may indicate these autistic dimensions in OCD patients.

Metacognitive processes in psychometrically defined schizotypy

Metacognitive abnormalities have been implicated in the experience of psychotic symptoms; however, the process through which this occurs remains unclear. The aim of this study was to clarify the association of self-reported schizotypy with metacognitive beliefs and neural activity related to higher-order cognition. Event-related potentials (ERPs) including the error-related negativity (ERN) and error positivity (Pe) were recorded during a Flanker task in 20 controls and 22 individuals with high self-reported schizotypy on the Schizotypal Personality Questionnaire-Brief Revised (SPQ-BR). Participants continuously evaluated their task performance and completed the Metacognitions Questionnaire-30 (MCQ-30). The high schizotypy group demonstrated higher scores on all subscales of the MCQ-30. In contrast, task performance, accuracy of self-performance evaluation, and amplitudes of the ERN and Pe did not differ between groups. The MCQ-30 factors that measure cognitive confidence and positive beliefs about worry significantly predicted SPQ-BR total score, whereas ERPs did not. High self-reported schizotypy appears to be more associated with dysfunctional metacognitive beliefs than physiological abnormalities in brain areas related to metacognition.

The validity of the Schizotypal Personality Questionnaire in a Greek sample: Tests of measurement invariance and latent mean differences

BACKGROUND

The Schizotypal Personality Questionnaire (SPQ) is a widely used scale for measuring schizotypal characteristics modeled on DSM-III-R criteria for schizotypal personality disorder (SPD). The aim of this study was to examine the factorial structure of the Greek SPQ, its factorial invariance across gender and different age groups and possible gender and age group differences at latent mean level.

METHODS

Eight hundred sixty-five community participants completed the Greek version of the SPQ.

RESULTS

With regard to the factorial structure of the original first-order model, the results showed that a seven-factor model (sub-scales "no close friends" with "constricted affect" and "ideas of reference" with "unusual perceptual experiences" were combined) was replicated adequately. Furthermore, the second-order "paranoid" model provided also adequate fit. With regard to the factorial invariance of the SPQ across gender and age, the analysis revealed that both, the first- and second-order models showed measurement invariance (configural, metric and structural) across gender and age groups (17-35 vs. 36-70). Latent mean differences across gender and age groups were also found.

CONCLUSIONS

Based on these findings, we can conclude that the Greek version of the SPQ is a psychometrically sound instrument for measuring schizotypal characteristics and a useful screening tool for SPD across gender and age.

Ten-year stability of self-reported schizotypal personality features in patients with psychosis and their healthy siblings

Schizotypal personality disorder (SPD) symptoms or features are common in patients with psychosis and their healthy relatives. However, the long-term stability of these SPD features and therefore their constituting enduring traits underlying vulnerability to psychosis remain to be clarified. Thirty-two patients with psychotic disorders and 29 of their healthy siblings were included from the long-term follow-up study of 89 nuclear families. Participants were clinically assessed by means of a semi-structured diagnostic interview, whereas the Schizotypal Personality Questionnaire-Brief (SPQ-B) was applied for the self-assessment of SPD symptoms. The assessments were carried out upon admission to the study and at follow-up, about 10 years later. The patients had higher scores than their siblings on the SPQ-B both at baseline and follow-up. In addition, self-reported SPD symptoms remained stable over time in total scores and in all the SPQ-B subscores, except for the SPQ-B Disorganization subscale. Self-reported SPD symptoms were stable over the long term among patients with psychotic disorders and their healthy siblings. This finding provides new support for including the SPD construct as a trait measure for studies addressing both vulnerability to psychosis in first-degree relatives of patients with psychosis and long-term persistence of symptoms in patients suffering from psychosis.

Psychotic and schizotypal symptoms in non-psychotic patients with obsessive-compulsive disorder

BACKGROUND

Research is scarce with regard to the role of psychotic and schizotypal symptoms in treatment of obsessive-compulsive disorder (OCD). The aim of the current study was to investigate the occurrence and specificity of psychotic and schizotypal symptoms among non-psychotic OCD patients, and to examine whether such symptoms was associated with response to exposure and response prevention (ERP), and whether ERP for OCD had an impact on psychotic and schizotypal symptoms.

METHODS

Non-psychotic OCD patients (n = 133) and a general non-psychotic psychiatric outpatient sample (n = 110) were assessed using self-report inventories before and after psychological treatment.

RESULTS

Non-psychotic OCD patients did not report greater degree of psychotic or schizotypal symptoms than the control group. Psychotic and schizotypal symptoms were not associated with OCD symptoms before or after ERP. Psychotic and schizotypal symptom were significantly reduced following ERP.

CONCLUSIONS

Psychotic and schizotypal symptoms seem to be equally prevalent among non-psychotic OCD patients and non-psychotic psychiatric controls. These symptoms were more linked to depressive symptoms than OCD symptoms. In non-psychotic OCD patients, ERP seems sufficient in reducing OCD symptoms despite the presence of psychotic- and schizotypal symptoms, and reductions in psychotic- and schizotypal symptoms were observed following ERP.

Childhood trauma and schizotypy: a systematic literature review

BACKGROUND

Schizotypy is a complex concept, commonly defined as a genetic vulnerability to schizophrenia that falls on a continuum between healthy variation and severe mental illness. There is a growing body of evidence supporting an association between childhood trauma and increased psychotic experiences and disorders. However, the evidence as to whether there is a similar association with schizotypy has yet to be systematically synthesized and assessed.

METHOD

We conducted a systematic search of published articles on the association between childhood trauma and schizotypy in four major databases. The search covered articles from 1806 to 1 March 2013 and resulted in 17,003 articles in total. Twenty-five original research studies met the eligibility criteria and were included in this review.

RESULTS

All 25 studies supported the association between at least one type of trauma and schizotypy, with odds ratios (ORs) ranging between 2.01 and 4.15. There was evidence supporting the association for all types of trauma, with no differential effects. However, there was some variability in the quality of the studies, with most using cross-sectional designs. Individuals who reported adverse experiences in childhood scored significantly higher on positive and negative/disorganized schizotypy compared to those who did not report such experiences.

CONCLUSIONS

All forms of childhood trauma and other stressful events (e.g. bullying) were found to be associated with schizotypy, with especially strong associations with positive schizotypy. However, because of the methodological limitations of several studies and a lack of further exploration of different possible mechanistic pathways underlying this association, more research is required.

Motivational predictors of psychometrically-defined schizotypy in a non-clinical sample: goal process representation, approach-avoid temperament, and aberrant salience

Patterns of problematic volitional control in schizotypal personality disorder pertaining to goal process representation (GPR), approach and avoidance temperament, and aberrant salience have not been widely investigated in emerging adults. The present study aimed to provide preliminary evidence for the utility of examining these three motivational constructs as predictors of high versus low levels of psychometrically-defined schizotypy in a non-clinic sample. When college students with high levels of self-reported schizotypy (n = 88) were compared to those with low levels (n = 87) by means of logistic regression, aberrant salience, avoidant temperament, and the self-criticism component of GPR together accounted for 51% of the variance in schizotypy group assignment. Higher score on these three motivational dimensions reflected a proclivity toward higher levels of schizotypy. The current findings justify the continued exploration of goal-related constructs as useful motivational elements in psychopathology research.

High and low schizotypal female subjects do not differ in spatial memory abilities in a virtual reality task

INTRODUCTION

Schizotypy is a psychological construct related to schizophrenia. The exact relationship between both entities is not clear. In recent years, schizophrenia has been associated with hippocampal abnormalities and spatial memory problems. The aim of this study was to determine possible links between high schizotypy (HS) and low schizotypy (LS) and spatial abilities, using virtual reality tasks. We hypothesised that the HS group would exhibit a lower performance in spatial memory tasks than the LS group.

METHODS

Two groups of female students were formed according to their score on the ESQUIZO-Q-A questionnaire. HS and LS subjects were tested on two different tasks: the Boxes Room task, a spatial memory task sensitive to hippocampal alterations and a spatial recognition task.

RESULTS

Data showed that both groups mastered both tasks. Groups differed in personality features but not in spatial performance. These results provide valuable information about the schizotypy-schizophrenia connections.

CONCLUSION

Schizotypal subjects are not impaired on spatial cognition and, accordingly, the schizotypy-schizophrenia relationship is not straightforward.

The independence of schizotypy from affective temperaments--a combined confirmatory factor analysis of SPQ and the short TEMPS-A

Sparse evidence of a co-aggregation of the risk of schizophrenia and bipolar disorder provides support for a shared but nonspecific genetic etiology of bipolar disorder and schizophrenia. Temperaments are conceptualized as trait sub-syndromic conditions of major pathologies. This study set out to test the hypothesis of a continuum between schizotypy and affective temperaments versus the alternative hypothesis of their independence based on a cross-sectional, survey design involving 649 (males: 47%) college students. The short 39-item TEMPS-A and the SPQ were used as measures of the affective temperaments and of schizotypy, respectively. Confirmatory factor analyses were applied to a unidimensional model, to a standard correlate traits model, to second-order representations of a common latent structure, and to a bifactor model. Confirmatory bifactor modeling provided evidence against a complete independence of the dimensions subsumed by the affective and the schizotypal traits. The best solution distinguished between two sub-domains grouping positive symptoms and negative symptoms as measured by the SPQ subscales, and a sub-domain related to the affective temperaments as measured by the TEMPS-A. Limitations due to the use of subscales from two different tools should be taken into account.

Examination of the factor structure of the Schizotypal Personality Questionnaire among British and Trinidadian adults

Much debate in schizotypal research has centred on the factor structure of the Schizotypal Personality Questionnaire (SPQ), with research variously showing higher-order dimensionality consisting of two to seven dimensions. In addition, cross-cultural support for the stability of those factors remains limited. Here, we examined the factor structure of the SPQ among British and Trinidadian adults. Participants from a White British subsample (n = 351) resident in the UK and from an African Caribbean subsample (n = 284) resident in Trinidad completed the SPQ. The higher-order factor structure of the SPQ was analysed through confirmatory factor analysis, followed by multiple-group analysis for the model of best fit. Between-group differences for sex and ethnicity were investigated using multivariate analysis of variance in relation to the higher-order domains. The model of best-fit was the four-factor structure, which demonstrated measurement invariance across groups. Additionally, these data had an adequate fit for two alternative models: (a) 3-factor and (b) modified 4-factor model. The British subsample had significantly higher scores across all domains than the Trinidadian group, and men scored significantly higher on the disorganised domain than women. The four-factor structure received confirmatory support and, importantly, support for use with populations varying in ethnicity and culture.

Relationship between lifetime suicide attempts and schizotypal traits in patients with schizophrenia

Patients with schizophrenia are at increased risk for suicide. Various risk factors for suicide have been reported in schizophrenia; however, few studies have examined the association between personality traits and suicidal behavior. We administered the Schizotypal Personality Questionnaire (SPQ) to 87 Japanese patients with schizophrenia (49 males; mean age 38.1±10.6 years) with and without a history of suicide attempts (SA and nSA groups, respectively), and 322 controls (158 males; mean age 40.8±13.9 years). As expected, an analysis of covariance (ANCOVA) controlling for age and sex showed that all SPQ indices (total SPQ score and all three factors, i.e., cognitive-perceptual, interpersonal, and disorganized) were significantly higher in patients with schizophrenia (SA+nSA groups), than controls (p<0.001 for all comparisons). Furthermore, there were significant differences in the total score and the interpersonal and disorganized factors between the SA and nSA groups (nSA<SA, p<0.01 for all comparisons). Receiver operating characteristic analysis showed that a total SPQ score of 33.5 was the optimal cut-off value to discriminate the SA group from the nSA group (χ²[1] = 10.6, p = 0.002, odds ratio: 4.7, 95% confidence interval: 1.8–12.1, sensitivity: 0.70, specificity: 0.67). These results suggest that high schizotypy is associated with lifetime suicide attempts, and that the total SPQ score might be useful to assess the risk of suicide attempt in patients with schizophrenia.

Natural speech comprehension in bipolar disorders: an event-related brain potential study among manic patients

BACKGROUND

Thought and language disturbances are crucial clinical features in Bipolar Disorders (BD), and constitute a fundamental basis for social cognition. In BD, clinical manifestations such as disorganization and formal thought disorders may play a role in communication disturbances. However, only few studies have explored language disturbances in BD at a neurophysiological level. Two main Event-Related brain Potentials (ERPs) have been used in language comprehension research: the N400 component, elicited by incongruous word with the preceding semantic context, and the Late Positive Component (LPC), associated with non-specifically semantic and more general cognitive processes. Previous studies provided contradictory results regarding N400 in mood disorders, showing either preserved N400 in depression or dysthymia, or altered N400 in BD during semantic priming paradigm. The aim of our study was to explore N400 and LPC among patients with BD in natural speech conditions.

METHODS

ERPs from 19 bipolar type I patients with manic or hypomanic symptomatology and 19 healthy controls were recorded. Participants were asked to listen to congruous and incongruous complete sentences and to judge the match between the final word and the sentence context. Behavioral results and ERPs data were analyzed.

RESULTS

At the behavioral level, patients with BD show worst performances than healthy participants. At the electrophysiological level, our results show preserved N400 component in BD. LPC elicited under natural speech conditions shows preserved amplitude but delayed latency in difference waves.

LIMITATIONS

Small size of samples, absence of schizophrenic group and medication status.

CONCLUSIONS

In contrast with the only previous N400 study in BD that uses written semantic priming, our results show a preserved N400 component in ecological and natural speech conditions among patients with BD. Possible implications in terms of clinical specificity are discussed.

Sex-specific associations between plasma oxytocin levels and schizotypal personality features in healthy individuals

OBJECTIVES

Oxytocin (OT) has been shown to play a crucial role in the biology of social interaction. Sex differences associated with this neuropeptide system have been reported. OT may serves as an indicator of interpersonal stress, especially in women. The aim of this study was to investigate the sex-specific associations between plasma OT levels and schizotypal personality features, especially in interpersonal dimension, in healthy individuals.

METHODS

Ninety six healthy participants, including 41 males and 55 females, were recruited. Fasting blood samples were analyzed by enzyme immunoassay of OT. The Schizotypal Personality Questionnaire (SPQ) was administered. Mann-Whitney U test was used to test the difference between male and female. Spearman's ρ correlation analysis (two-tailed) was carried out to examine the association between OT level and SPQ score.

RESULTS

The results showed that OT level was significantly positively correlated with total score and interpersonal dysfunction dimensional scores of the SPQ only in females.

CONCLUSIONS

Although the causal relationship remains unclear, our findings provide further evidence to support the sexual dimorphic role of OT in interpersonal biology. Moreover, the effect of sex difference also is taken into consideration.

Dimensional endophenotypes in bipolar disorder: affective dysregulation and psychosis proneness

BACKGROUND

The clinical phenotype of bipolar disorder (BPD) is heterogeneous and the genetic architecture of the disorder is complex and not well understood. Given these complications, it is possible that the identification of intermediate phenotypes ("endophenotypes") will be useful in elucidating the complex genetic mechanisms that result in the disorder. The examination of unaffected relatives is critical in determining whether a particular trait is genetically-relevant to BPD. However, few dimensional traits related to BPD have been assessed in unaffected relatives of patients.

METHODS

We assessed affective temperament and schizotypy in 55 discordant sibling pairs and 113 healthy controls (HCs) using the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego, Auto-questionnaire version (TEMPS-A) to assess affective temperament and the Schizotypal Personality Questionnaire (SPQ) to assess schizotypy.

RESULTS

BPD patients scored significantly higher than HCs on all subscales of the SPQ and on all but one subscale (hyperthymic) of the TEMPS-A (all p<0.01). Siblings demonstrated scores that were significantly intermediate to patients and HCs on the anxious subscale of the TEMPS-A and on the interpersonal deficits and disorganized subscales of the SPQ.

LIMITATIONS

We did not investigate the BPD spectrum as most patients were diagnosed with BPD I (n=47). Most of the patients had experienced psychosis (n=42) and so we were unable to examine whether psychosis status impacted upon affective temperament or schizotypy in patients or their siblings.

CONCLUSION

These data suggest that schizotypy and affective temperament represent dimensional traits that are likely to underlie the genetic risk for BPD.

Schizotypy and hemispheric asymmetry: Results from two Chapman scales, the O-LIFE questionnaire, and two laterality measures

Schizotypy is a multidimensional personality construct representing the extension of psychosis-like traits into the general population. Schizotypy has been associated with attenuated expressions of many of the same neuropsychological abnormalities as schizophrenia, including atypical pattern of functional hemispheric asymmetry. Unfortunately the previous literature on links between schizotypy and hemispheric asymmetry is inconsistent, with some research indicating that elevated schizotypy is associated with relative right over left hemisphere shifts, left over right hemisphere shifts, bilateral impairments, or with no hemispheric differences at all. This inconsistency may result from different methodologies, scales, and/or sex proportions between studies. In a within-participant design we tested for the four possible links between laterality and schizotypy by comparing the relationship between two common self-report measures of multidimensional schizotypy (the O-LIFE questionnaire, and two Chapman scales, magical ideation and physical anhedonia) and performance in two computerised lateralised hemifield paradigms (lexical decision, chimeric face processing) in 80 men and 79 women. Results for the two scales and two tasks did not unequivocally support any of the four possible links. We discuss the possibilities that a link between schizotypy and laterality (1) exists but is subtle, probably fluctuating, unable to be assessed by traditional methodologies used here; (2) does not exist, or (3) is indirect, mediated by other factors (e.g., stress-responsiveness, handedness, drug use) whose influences need further exploration.

Psychosis-proneness and the rubber hand illusion of body ownership

Psychosis and psychosis-proneness are associated with abnormalities in subjective experience of the self, including distortions in bodily experience that are difficult to study experimentally due to lack of structured methods. In 55 healthy adults, we assessed the relationship between self-reported psychosis-like characteristics and susceptibility to the rubber hand illusion of body ownership. In this illusion, a participant sees a rubber hand being stroked by a brush at the same time that they feel a brush stroking their own hand. In some individuals, this creates the bodily sense that the rubber hand is their own hand. Individual differences in positive (but not negative) psychosis-like characteristics predicted differences in susceptibility to experiencing the rubber hand illusion. This relationship was specific to the subjective experience of rubber hand ownership, and not other unusual experiences or sensations, and absent when a small delay was introduced between seeing and feeling the brush stroke. This indicates that individual differences in susceptibility are related to visual-tactile integration and cannot be explained by differences in the tendency to endorse unusual experiences. Our findings suggest that susceptibility to body representation distortion by sensory information may be related or contribute to the development of psychosis and positive psychosis-like characteristics.

Schizotypal traits are associated with poorer identification of emotions from dynamic stimuli

Recent research suggests that the emotion recognition difficulties seen in schizophrenia may also be present to a lesser degree in non-clinical individuals who report attenuated expressions of schizophrenia-like symptoms (schizotypy). However, evidence in non-clinical samples primarily comes from studies employing static facial emotion tasks, and it is not clear whether poorer emotion recognition in schizotypy persists when people have access to a broader range of emotional cues more representative of typical face-to-face social interactions. A community sample of 151 adults completed measures of schizotypal traits, IQ, and a task that assessed emotion recognition using dynamic video-based stimuli. Global schizotypy and positive schizotypal traits were each associated with poorer emotion recognition. Negative schizotypy was not associated with emotion recognition overall, but was associated with errors in recognising positive emotions. It appears that poorer emotion recognition in schizotypy is not limited to single-channel stimuli, but can be seen even when multiple emotional cues are available. Thus, individuals with high levels of schizotypal traits, and positive features in particular, may have greater difficulty when it comes to 'reading' the emotions of others in everyday social interactions.

Associations among metacognitive beliefs, anxiety and positive schizotypy during adolescence

The expression of early delusion and hallucination-like symptoms, known as positive schizotypy (PS), holds predictive power for later development of psychotic disorders. However, little is known about the psychological and emotional processes promoting the expression of PS during adolescent development. Our study's objective was to examine the nature of the relationships between adolescent PS and two dimensions previously identified to contribute to adult positive symptoms of psychosis, metacognitive beliefs and anxiety. Using a structural equation modeling design, data from self-report questionnaires measuring anxiety, metacognitive beliefs, and PS were collected from 179 adolescents aged 12 to 19 years. Our results indicate that although metacognitive beliefs significantly influence adolescent PS and anxiety, maladaptive contradictory metacognitive beliefs specifically potentiate positive schizotypal expression in hallucination-prone adolescents. Furthermore, we observe that PS and anxiety entertain reciprocal relationships. These findings suggest that relationships between metacognitive beliefs, anxiety, and PS can already be observed during adolescence.