The multidimensionality of schizotypy

Differential Risk: Gender and Racial Differences in the Relationship between Trauma, Discrimination, and Schizotypy

Traumatic experiences are associated with increased experiences of positive schizotypy. This may be especially important for People of Color, who experience higher rates of trauma and racial discrimination. No study to date has examined how racial disparities in traumatic experiences may impact schizotypy. Furthermore, of the studies that have examined the relationship between trauma and schizotypy, none have examined racial discrimination as a potential moderator. The present study examined if racial discrimination moderates the relationship between trauma and multidimensional (positive, negative, and disorganized) schizotypy. In a sample of 770 college students, we conducted chi-squared analyses, analyses of variance, and stepwise regressions. We found that Black students experienced significantly higher racial discrimination and trauma than Latinx and Asian students. Furthermore, Black and Latinx students experienced significantly more multidimensional schizotypy items than Asian students. Trauma and racial discrimination explained 8 to 23% of the variance in each dimension of schizotypy. Racial discrimination did not moderate the relationships between trauma and multidimensional schizotypy. Our findings suggest that we need to examine risk factors that may prevent recovery from psychotic disorders. Additionally, disorganized schizotypy showed the most robust associations and may be a critical site of intervention.

Moral learning and positive schizotypy: Social cognitive mechanisms in psychosis- proneness

BACKGROUND

Delusional thoughts such as paranoia and conspiratorial thinking reflect beliefs in others' intentions to do harm. Given the integral role of harm evaluation in moral cognition, a better understanding of how psychosis-prone individuals process others' moral characters may provide insights into social cognitive mechanisms of these types of delusions.

METHODS

An online sample of 293 participants was drawn from the general population, using Amazon Mechanical Turk. Participants performed a moral inference task, where they predicted and judged the binary choices of two fictitious agents ("good" or "bad") to impose harm under different levels of financial incentives. An investment game involving the same agents then examined participants' trust behavior. Psychosis-proneness was measured with the Multidimensional Schizotypy Scale Brief Edition.

RESULTS

A set of multiple regressions showed that positive schizotypy was associated with a lower yet more confident pre-experimental expectation of the agent's moral character, lower prediction accuracy of the agent's harm preferences, less belief revision, and undifferentiated perception of the good and bad agents' characters. Positive schizotypy was also related to higher expectations for reciprocity in the investment game, regardless of agent characters.

CONCLUSION

Our findings suggest that inflexible beliefs associated with psychosis-proneness extend beyond negative prior expectations, also reflecting difficulties in moral learning. The resulting undifferentiated moral impressions might contribute to undue suspicion of benevolent individuals and increased gullibility to malicious ones, potentially further strengthening conspiratorial beliefs.

Nabilone Impairs Spatial and Verbal Working Memory in Healthy Volunteers

Background: Memory impairments and psychosis-like experiences can be adverse effects of cannabis use. However, reports on the cognitive impact of cannabis use are not consistent. There are also limited studies on the psychotomimetic effects of cannabinoid compounds to reveal the association between cannabis and psychosis. Therefore, we investigated the effect of acute cannabinoid intoxication on verbal working memory (VWM) and spatial working memory (SWM) following oral doses of the synthetic cannabinoid agonist, nabilone (1-2 mg, oral). We further investigated the effect of nabilone on psychosis-like experiences (schizotypy scores) and associations of schizotypy with VWM and SWM. Methods: Healthy participants (n=28) completed spatial and digit span tasks across different delay conditions (0, 6, 12, and 18 sec) after receiving nabilone (1-2 mg, PO) or placebo in a randomized, double-blind, counterbalanced, crossover manner. A subset of participants completed a short battery of schizotypy measures (n=25). Results: Nabilone impaired VWM (p=0.03, weak effect size η2=0.02) and SWM (p=0.00016, η2=0.08). Nabilone did not significantly change overall schizotypy scores. Schizotypy scores were negatively correlated with working memory (WM) averaged across all delays and both modalities, under placebo (ρ=-0.41, p=0.04). In addition, there were significant negative correlations between occasions of cannabis use and overall WM averaged scores across drug treatments (ρ=-0.49, p=0.007) and under placebo (ρ=-0.45, p=0.004). The results showed that the drug effect in the less frequent cannabis users was more pronounced on the SWM (p<0.01) and VWM (p<0.01), whereas there appeared to be little drug effect in the frequent cannabis users. Conclusion: Low doses of synthetic cannabinoid impaired SWM and VWM, indicating that exogenous activation of the cannabinoid system influences cognitive performance. Further, the results replicated previous findings that schizotypy is correlated with deficits in WM. Clinical Trial Registry Name: Nabilone and caffeine effects on the perceptions of visually, auditory, tactile and multimodal illusions in healthy volunteers. Clinical Trial Registration Number: CT-2018-CTN-02561 (Therapeutic Goods Administration Clinical Trial Registry) and ACTRN12618001292268 (The Australian New Zealand Clinical Trials Registry).

Examining Schizotypal Personality Scales Within and Across Interpersonal Circumplex Surfaces

Differing perspectives on the operationalization of schizotypal personality pathology (STPP) have led to numerous multidimensional assessment measures. The current study applied the interpersonal construct validation approach to self-report data from 856 undergraduate students to formally examine the interpersonal content, similarities, and differences in the subscales of four measures of STPP within and across two interpersonal circumplex surfaces using a bootstrapping methodology for computing confidence intervals around circumplex structural summary method parameters. Results suggested that negative-like expressions of STPP are prototypically and distinctively interpersonal constructs associated with cold and socially avoidant interpersonal problems and hypersensitivity to others' warmth and affection. Positive-like expressions of STPP as assessed by two out of four measures were prototypically and distinctively interpersonal constructs associated with vindictiveness. Across four measures, there was notable overlap in interpersonal correlates among related subscales, suggesting convergent validity. However, subscales containing social anxiety content were associated with more submissive (i.e., socially avoidant) interpersonal problems than subscales without social anxiety content.

Dexamphetamine influences funneling illusion based on psychometric score

OBJECTIVES

Our team previously showed that like the experience of the rubber hand illusion (RHI) in people with schizophrenia and their offspring¸ dexamphetamine administration to healthy volunteers increases the stimulus binding windows (BWs) in RHI. It is not clear if similar expansions of BWs are present for unimodal illusions. Studies have also shown that subjective or objective effects of amphetamine would be linked to between-person variations in personality measures. Therefore, we aimed to examine the effect of dexamphetamine (DEX), a dopamine-releasing stimulant, on illusory perception using unimodal sensory stimuli (Tactile Funneling Illusion [TFI]) across both temporal and spatial variables. We further examined the relationship between changes in psychometric scores and changes in illusion perception induced by dexamphetamine.

METHODS

Healthy subjects (N = 20) participated in a randomized, double-blind, counter-balanced, placebo-controlled, cross-over study. The effects of dexamphetamine (0.45 mg/kg, PO, q.d.) on funneling and error of spatial localization (EL) were examined using TFI. Psychotomimetic effects were assessed using a battery of psychological measures.

RESULTS

Dexamphetamine did not significantly increased the funneling illusion (p = 0.88) or EL (p = 0.5), relative to placebo. However, the degree of change in psychometric scores following dexamphetamine positively correlated with changes in funneling (ρ = 0.48, p = 0.03, n = 20), mainly at 0 ms delay condition (ρ = 0.6, p = 0.004, n = 20).

CONCLUSION

Unlike multimodal illusions, alteration of BWs does not occur for unimodal illusions after administration of a dopamine-releasing agent. However, our findings indicate that moderate release of dopamine, through its psychotomimetic effect, indirectly influences unimodal illusion.

Facial emotion recognition and schizotypal traits: A systematic review of behavioural studies

AIM

Previous research has indicated that individuals expressing high schizotypal traits and patients with Schizotypal Personality Disorder (SPD), show deficits in facial emotion recognition, compared to low schizotypal or control groups. On the other hand, non-significant findings also exist and the association of facial emotion recognition deficits with the different schizotypal dimensions is not well defined, thus limiting any conclusive outcomes. Therefore, the aim of this systematic review was to further clarify this relationship.

METHODS

PsychInfo, Web of Science, Scopus and PubMed were systematically searched, and 23 papers with a cross-sectional design were selected. Nineteen studies examined individuals with high schizotypal traits and four studies evaluated SPD individuals with behavioural facial emotion recognition paradigms and self-report measures or clinical interviews for schizotypal traits. All selected studies were published between 1994 and August 2020.

RESULTS

According to the evidence of studies, high schizotypal individuals and SPD patients have poorer performance in facial emotion recognition tasks. Negative schizotypy was related to lower accuracy for positive and negative emotions and faster emotion labeling while positive schizotypy was associated with worse accuracy for positive, negative and neutral emotions and more biases. Disorganized schizotypy was associated with poorer accuracy for negative emotions and suspiciousness with higher accuracy for disgust faces but lower total accuracy.

CONCLUSIONS

These findings are consistent with the vulnerability for schizophrenia spectrum disorders and support the idea that emotion recognition deficits are trait markers for these conditions. Thus, the effectiveness of early-intervention programmes could increase by also targeting this class of deficits.

Schizotypal dimensions are associated with current but not former tobacco consumption

OBJECTIVES

We aimed to study the relationship between tobacco smoking and attenuated psychosis measures taking into account several aspects of tobacco consumption that to date have not been explored and that could help understand this association, such as age of onset, the influence of former consumption and the duration of abstinence.

METHODS

We investigated, in a sample of 580 students, the relationship between schizotypy (using the schizotypal personality questionnaire-brief in a Likert format) and smoking status, nicotine dependence (measured with the Fagerström test for nicotine dependence), age of onset of smoking and in former smokers, duration of smoking abstinence.

RESULTS

35.2% of the students were current smokers and 13.4% were former smokers. We found that current but not former smokers had higher scores of schizotypy (total, positive and disorganized) than non-smokers. We found no association between schizotypy scores and nicotine dependence or earlier age of onset of smoking. The duration of smoking abstinence, in former smokers, was inversely correlated to the score of positive and total schizotypy.

CONCLUSIONS

Our results suggest that tobacco has a reversible effect on schizotypy, but more studies with a different design (controlled, longitudinal) and a more thorough exploration of potential confounders (e.g. cannabis) are needed before a firm conclusion can be reached.

Assessing the dimensionality of scores derived from the Revised Formal Thought Disorder Self-Report Scale in schizotypy

The current work explored the dimensionality and convergent validity of responses to Barrera et al.'s (2015) 29-item Formal Thought Disorder-Self Scale (FTD-SS) obtained in two non-clinical samples. Exploratory factor analyses were conducted in Sample 1 (n = 324), yielding evidence of three correlated factors, although simple structure was not achieved until nine items were removed. Support for the correlated three factors model of responses to the revised 20-item scale (FTD-SS-R) was replicated when a confirmatory factor analysis was conducted in Sample 2 (n = 610). Finally, convergent associations were found between FTD-SS-R scores and scores from other schizotypy measures across both samples, though these measures only explained half of the variance in FTD-SS-R scores. Additional research is needed to evaluate the appropriateness of the items and incremental validity of the scale in non-clinical samples.

Association of Multidimensional Schizotypy with PID-5 Domains and Facets

The underlying vulnerability for schizophrenia-spectrum disorders is expressed across a continuum of clinical and subclinical symptoms referred to as schizotypy. Schizotypy is a multidimensional construct with positive, negative, and disorganized dimensions. The present study examined associations of positive, negative, and disorganized schizotypy with pathological personality traits and facets assessed by the Personality Inventory for DSM-5 (PID-5) in 1,342 young adults. As hypothesized, positive schizotypy was associated with the PID-5 psychoticism domain and facets, negative schizotypy was associated with the detachment domain and facets and the restricted affectivity facet, and disorganized schizotypy's strongest associations were with the distractibility and eccentricity facets and the negative affect domain. The PID-5 facets accounted for upwards of two thirds of the variance in each schizotypy dimension. The authors conclude by providing regression-based algorithms for computing positive, negative, and disorganized schizotypy scores based on the PID-5 facets.

Internet addiction is associated with psychological distress in highly schizotypal students

BACKGROUND

There is some limited evidence of an association between technology addictions and emergence of pre-psychotic symptoms, high psychoticism, psychotic like experiences and high schizotypy among young non-clinical adults. These addictions and their subsequent distress are likely to contribute to transition to psychosis in individuals at risk. We aimed to compare smartphone, Internet and Facebook addictions between low and high schizotypal individuals; and to explore the association between these addictions and distress in the high schizotypy group.

METHODS

From a pool of 700 students, the final sample consisted of 74 low schizotypal and 70 high schizotypal students. The Schizotypal Personality Questionnaire, the Bergen Facebook Addiction Scale, the Internet Addiction Test, the Smartphone Addiction Scale-Short Version and the Depression, Anxiety and Stress Scales.

RESULTS

Students of the high schizotypy group displayed significantly greater scores on smartphone (p < .001), Internet (p < .001) and Facebook (p = .001) addictions scales, as compared to those of the low schizotypy group. After controlling for potential confounders, Internet addiction predicted psychological distress in the high schizotypy group (R²  = 0.380, F_(13,55)  = 2.597, p < .001) and explained an additional 19.7% of variation in Depression, Anxiety and Stress Scales total scores in the final model.

CONCLUSION

Although preliminary, our findings shed light on relatively new avenues for prevention and early intervention in psychosis. It is recommended to raise awareness about Internet addiction risks, particularly among vulnerable young adults; and to find ways to turn Internet into a protective rather than stressor factor, by utilizing it as a resource in the care pathway.

Investigating predictors contributing to the expression of schizotypy during the COVID-19 pandemic

The coronavirus (COVID-19) pandemic has caused major disruptions to social and other forms of functioning, which may influence schizotypy expression. The current study aimed to explore possible distal and proximal predictors contributing to schizotypy in a sample of the Australian general population during the COVID-19 pandemic. The COvid-19 and you: mentaL heaLth in AusTralia now survEy (COLLATE) project is an online mental health study aimed at tracking key mental health indicators over the progression of the pandemic. Adults residing in Australia were invited to take part using non-discriminative snowball sampling. Demographic-clinical information was collected for 850 participants in either October 2020 or January 2021. To assess schizotypy facets, the Launay-Slade Hallucinations Scale-Extended (LSHS-E) and Peters Delusions Inventory (PDI-21) were used to measure hallucination and delusion proneness respectively. Generalised linear models (with gamma and negative binomial distributions) were employed. Age, negative emotions and loneliness significantly contributed to both hallucination and delusion proneness; gender, education and religiosity also significantly contributed to delusion proneness, in the final regression models. Our study corroborated the specific contribution of loneliness, amongst other factors, in the prediction of schizotypy facets. Tackling loneliness represents a public health challenge that needs to be urgently addressed, especially in the face of the ongoing COVID-19 pandemic.

Suicidal ideation, suicide literacy and stigma, disclosure expectations and attitudes toward help-seeking among university students: The impact of schizotypal personality traits

BACKGROUND

Similarly to patients with schizophrenia, non-clinical individuals with schizotypal traits have been reported to show an increased risk for suicide-related outcomes. We aimed to assess suicidal ideation, and to determine factors that may have associations with help-seeking attitudes in high schizotypal individuals as compared to low schizotypal individuals.

METHOD

We carried out a cross-sectional survey. The Schizotypal Personality Questionnaire, the attitudes toward seeking professional psychological help scale-short form, the disclosure expectations scale, the scale of suicide ideation, the stigma of suicide scale-short form, the literacy of suicide scale, and the depression anxiety stress scales were administered to 504 college students. A total of 51 students were classified in the high-schizotypy group, and 50 were classified in the low-schizotypy group.

RESULTS

High-schizotypal students experienced significantly more suicidal ideation, had greater literacy of suicide, had more glorification of suicide, had higher anticipated risks of disclosure and more negative help-seeking attitudes than low-schizotypal students. After controlling for sociodemographic (age, gender, income and tobacco use) and psychosocial variables (personal psychiatric history, family history of suicide, personal history of suicide attempt[s]), depression and suicide ideation), disclosure expectations had both a significant negative independent effect through anticipated risks, and a positive independent effect through anticipated benefits, on high-schizotypal students' help-seeking attitudes.

CONCLUSION

The apprehension and reluctance to seek help found in high-schizotypal students highlight an urgent need to further understand barriers to help-seeking among at-risk adolescents, and what may motivate them to reach out for support when they are more at-risk for suicide.

Longitudinal bifactor modeling of anxiety, depression and schizotypy - The role of rumination as a shared mechanism

A bifactor model with a general (p) factor reflecting shared variance and specific factors reflecting additional variance in individual symptoms has been introduced to explain common co-occurrence among anxiety, depression and schizotypy. However, longitudinal evidence is lacking and the validity of bifactor modeling is debatable. The current study aimed to examine the presence of the p factor together with specific factors in accounting for relationships between anxiety, depression and schizotypy both cross-sectionally and longitudinally, and to investigate the relationship between these factors and rumination. A validated sample of university students were surveyed on levels of anxiety, depression, schizotypy and rumination at baseline (N = 2291), one year (N = 1833) and two years (N = 1656). Models were estimated using exploratory structural equation modeling (ESEM) and compared at each time point. Longitudinal invariance of the best-fitting model was examined and all potential within- and between-factor stability pathways were tested in an SEM framework. A bifactor model with a p factor and four specific factors (representing residual information of composite anxiety and depression, cognitive-perceptual, interpersonal and disorganized schizotypy respectively) consistently outperformed a correlated-factors model. The bifactor structure appeared longitudinally stable. Within-factor stabilities were moderate, and between-factor pathways reflected a few significant interactions, mostly involving the p factor. Rumination was independently associated with p and four specific factors at each time point. Therefore, there is a p factor accounting for concurrent and sequential co-occurrence of anxiety, depression and schizotypy. Rumination explained partly the p and specific factors. Transdiagnostic interventions should target rumination.

Cortical and subcortical neuroanatomical signatures of schizotypy in 3004 individuals assessed in a worldwide ENIGMA study

Neuroanatomical abnormalities have been reported along a continuum from at-risk stages, including high schizotypy, to early and chronic psychosis. However, a comprehensive neuroanatomical mapping of schizotypy remains to be established. The authors conducted the first large-scale meta-analyses of cortical and subcortical morphometric patterns of schizotypy in healthy individuals, and compared these patterns with neuroanatomical abnormalities observed in major psychiatric disorders. The sample comprised 3004 unmedicated healthy individuals (12-68 years, 46.5% male) from 29 cohorts of the worldwide ENIGMA Schizotypy working group. Cortical and subcortical effect size maps with schizotypy scores were generated using standardized methods. Pattern similarities were assessed between the schizotypy-related cortical and subcortical maps and effect size maps from comparisons of schizophrenia (SZ), bipolar disorder (BD) and major depression (MDD) patients with controls. Thicker right medial orbitofrontal/ventromedial prefrontal cortex (mOFC/vmPFC) was associated with higher schizotypy scores (r = 0.067, p_FDR = 0.02). The cortical thickness profile in schizotypy was positively correlated with cortical abnormalities in SZ (r = 0.285, p_spin = 0.024), but not BD (r = 0.166, p_spin = 0.205) or MDD (r = -0.274, p_spin = 0.073). The schizotypy-related subcortical volume pattern was negatively correlated with subcortical abnormalities in SZ (rho = -0.690, p_spin = 0.006), BD (rho = -0.672, p_spin = 0.009), and MDD (rho = -0.692, p_spin = 0.004). Comprehensive mapping of schizotypy-related brain morphometry in the general population revealed a significant relationship between higher schizotypy and thicker mOFC/vmPFC, in the absence of confounding effects due to antipsychotic medication or disease chronicity. The cortical pattern similarity between schizotypy and schizophrenia yields new insights into a dimensional neurobiological continuity across the extended psychosis phenotype.

Adaptive and maladaptive features of schizotypy clusters in a community sample

Schizotypal personality traits correlate with psychopathology and impaired functional outcome. Yet advantageous aspects of positive schizotypy may exist which could promote resilience and creativity, and several studies have identified a high positive but low negative schizotypy group with some signs of adaptation. The aim of our study was to clarify whether such individuals demonstrate only traits associated with well-being, or they also have traits that predict impairment. Participants (N = 643 students, 71.5% female) completed measures of schizotypy, resilience, self-esteem, self-concept clarity, and absorption. We identified four clusters: an overall low schizotypy, an overall high schizotypy, a disorganised-interpersonal schizotypy and a positive schizotypy cluster. The overall high schizotypy cluster seemed to be the most vulnerable as it was the least resilient and showed widespread maladaptation, whereas the high positive schizotypy cluster had intact self-esteem and high resilience and its elevated absorption may hold the promise for adaptive outcomes such as creativity and positive spirituality. However, the high positive schizotypy cluster lacked self-concept clarity. The results suggest that individuals showing high positive and low negative schizotypy demonstrate features promoting mental well-being to an extent that is higher than in all the other clusters, while their self-concept impairment is similar to that observed in the high and the disorganised-interpersonal schizotypy clusters. Better understanding of these factors could be informative for prevention and treatment of psychosis-spectrum disorders.

How did Tunisian university students cope with fear of COVID-19? A comparison across schizotypy features

Background

Little consideration has been given to the impact of COVID-19 on people at risk of psychosis despite their particular preexisting vulnerability. We aimed to examine the role of coping strategies in determining the levels of fear in nonclinical students with high levels of self-reported schizotypal personality traits as compared to low-schizotypy controls.

Method

This was a cross-sectional survey. The Schizotypal Personality Questionnaire, the Fear of COVID-19 Scale and The Brief-Coping Orientation to Problems Experienced were used.

Results

High-schizotypy students had significantly higher maladaptive strategies scores and higher levels of fear of COVID-19 as compared to low-schizotypy students. Multivariate analyses have shown that high-schizotypy individuals were likely to rely on coping responses that are maladaptive (venting) and have potential exacerbating effects on fear of COVID-19, whereas low-schizotypy individuals were likely to use adaptive responses (acceptance) that seemed to be effective in reducing fear of COVID-19.

Conclusion

This study provided preliminary cross-sectional evidence for a differential impact of COVID-19 on individuals according to their schizotypy features. However, larger longitudinal population-based studies are necessary to confirm our findings.

Altered cortico-striatal functional connectivity in people with high levels of schizotypy: A longitudinal resting-state study

PURPOSE OF THE RESEARCH

Cortico-striatal functional connectivity has been implicated in the neuropathology of schizophrenia. However, the longitudinal relationship between the cortico-striatal connectivity and schizotypy remains unknown. We examined the resting-state fMRI connectivity in 27 individuals with a high level of schizotypy and 20 individuals with a low level of schizotypy at baseline and 18 months later. Correlations between changes in cortico-striatal connectivity and changes in schizotypy scores over time were examined.

PRINCIPAL RESULTS

We found both increased and decreased cortico-striatal connectivity in individuals with a high level of schizotypy at baseline. Over time, these individuals showed improvement in both the negative and positive schizotypal domains. Changes in striatal-insula connectivity were positively correlated with changes in positive schizotypy from baseline to follow-up.

MAJOR CONCLUSIONS

Our results suggested impaired cortico-striatal connectivity in individuals with a high level of schizotypy. The dysconnectivity mainly involves the dorsal striatum. The connectivity between the dorsal striatum and the insula may be a putative marker for temporal changes in positive schizotypy.

The association of striatal volume and positive schizotypy in healthy subjects: intelligence as a moderating factor

BACKGROUND

Schizotypy, a putative schizophrenia endophenotype, has been associated with brain-structural variations partly overlapping with those in psychotic disorders. Variations in precuneus structure have been repeatedly reported, whereas the involvement of fronto-striatal networks - as in schizophrenia - is less clear. While shared genetic architecture is thought to increase vulnerability to environmental insults, beneficial factors like general intelligence might buffer their effect.

METHODS

To further investigate the role of fronto-striatal networks in schizotypy, we examined the relationship of voxel- and surface-based brain morphometry and a measure of schizotypal traits (Schizotypal Personality Questionnaire, with subscores Cognitive-Perceptual, Interpersonal, Disorganised) in 115 healthy participants [54 female, mean age (s.d.) = 27.57(8.02)]. We tested intelligence (MWT-B) as a potential moderator.

RESULTS

We found a positive association of SPQ Cognitive-Perceptual with putamen volume (p = 0.040, FWE peak level-corrected), moderated by intelligence: with increasing IQ, the correlation of SPQ Cognitive-Perceptual and striatal volume decreased (p = 0.022). SPQ Disorganised was positively correlated with precentral volume (p = 0.013, FWE peak level-corrected). In an exploratory analysis (p < 0.001, uncorrected), SPQ total score was positively associated with gyrification in the precuneus and postcentral gyrus, and SPQ Disorganised was negatively associated with gyrification in the inferior frontal gyrus.

CONCLUSIONS

Our findings support the role of fronto-striatal networks for schizotypal features in healthy individuals, and suggest that these are influenced by buffering factors like intelligence. We conclude that protective factors, like general cognitive capacity, might attenuate the psychosis risk associated with schizotypy. These results endorse the idea of a continuous nature of schizotypy, mirroring similar findings in schizophrenia.

A brief questionnaire measure of multidimensional schizotypy predicts interview-rated symptoms and impairment

The present study employed structured diagnostic interviews to assess the construct validity of the brief version of the Multidimensional Schizotypy Scale (MSS-B), which was developed to assess positive, negative, and disorganized dimensions of schizotypy. It was hypothesized that the MSS-B subscales would be associated with differential patterns of symptoms and impairment, comparable to findings for the full-length MSS. A total of 177 young adults completed structured diagnostic interviews assessing symptoms and impairment. As hypothesized, MSS-B positive schizotypy was significantly associated with interview ratings of positive (psychotic-like) symptoms, as well as schizotypal and paranoid personality disorder traits. MSS-B negative schizotypy was associated with interview ratings of negative symptoms, as well as schizoid, paranoid, and schizotypal traits. Furthermore, negative schizotypy predicted Cluster A personality disorder diagnoses. MSS-B disorganized schizotypy was associated with interview ratings of disorganized symptoms. All three schizotypy dimensions were associated with impaired functioning. This was the first study to evaluate the validity of the MSS-B using interview measures, and the pattern of findings for each MSS-B subscale was closely comparable to the findings for the full-length MSS. Contrary to our hypothesis, cannabis use was largely unassociated with psychotic-like symptoms and did not moderate the expression of the schizotypy dimensions. The MSS-B has good psychometric properties, high concordance with the full-length MSS, and good construct validity. Thus, it appears to be a promising brief alternative to traditional schizotypy measures.

Examining Self-Reported Thought Disorder: Continuous Variation, Convergence with Schizotypy, and Cognitive Correlates

When measured from the perspective of a clinician, the severity of 'objective' thought disorder (TD) has been found to vary continuously between people with and without psychosis-related diagnoses, and has been linked with semantic and executive dysfunctions in people with psychosis. Measures of 'subjective' TD that are derived from a first-person perspective have also been produced, but their relationships with objective TD and cognition are unclear. The aims of the current study were: to determine whether responses on a self-report TD questionnaire correspond with responses to a self-report measure of schizotypal disorganization; and to explore the association between these self-reported subjective TD severities and cognitive performance. Data was collected from a sample of 33 people without psychiatric diagnoses and 38 people diagnosed with schizophrenia or schizoaffective disorder evincing mild symptomatology, and this data was pooled for analysis in accordance with the continuum model. Self-reported TD frequencies were associated with the endorsement of disorganized schizotypal experiences. Moreover, self-reported TD frequencies showed relationships with measures of semantic and executive functioning. Thus, at mild severities, self-reported TD shows continuous variation and is associated with altered cognitive function.

Validation of the Chinese version of the Multidimensional Schizotypy Scale (MSS): Convergent evidence from exploratory and confirmatory factor analyses

BACKGROUND

Schizotypy has been shown to be a time-stable construct that exists across the schizophrenia spectrum. The Multidimensional Schizotypy Scale (MSS) was developed to capture the three factors underlying schizotypy: positive, disorganized and negative schizotypy. However, a recent validation study reported a four-factor construct with an additional negative social anhedonia factor. The factor structure of the Chinese version of the MSS remains unknown. This study aimed to identify and validate the factor structure of the Chinese version of the MSS.

METHODS

We recruited 641 Chinese speakers via on-line advertisement. We administered the Chinese version of the MSS, which was a self-report instrument. The scale consists of 77 items with true or false response options. We identified and removed 43 outliers. Finally, a total of 294 participants were randomly selected as the derivative sample for exploratory factor analysis (EFA). The remaining 304 participants were retained as the validation sample for confirmatory factor analysis (CFA).

RESULTS

EFA identified four factors: the positive factor, the disorganization factor, the negative affective and motivational anhedonia factor, and the negative social anhedonia factor. The EFA-identified four-factor model was compared with the unidimensional, three-factor bifactorial and theoretical three-factor models using CFAs. The three-factor bifactorial model fitted the data better than the EFA-identified four-factor model.

CONCLUSION

Our finding suggests that the Chinese version of the MSS is a valid tool for assessing schizotypy in the Chinese setting.

Dimensional and discrete variations on the psychosis continuum in a Dutch crowd-sourcing population sample

Background

Mild psychotic experiences are common in the general population. Although transient and benign in most cases, these experiences are predictive of later mental health problems for a significant minority. The goal of the present study was to perform examinations of the dimensional and discrete variations in individuals’ reporting of subclinical positive and negative psychotic experiences in a unique Dutch internet-based sample from the general population.

Methods

Positive and negative subclinical psychotic experiences were measured with the Community Assessment of Psychic Experiences in 2870 individuals. First, the prevalence of these experiences and their associations with demographics, affect, psychopathology and quality of life were investigated. Next, latent class analysis was used to identify data-driven subgroups with different symptom patterns, which were subsequently compared on aforementioned variables.

Results

Subclinical psychotic experiences were commonly reported. Both positive and negative psychotic experiences were associated with younger age, more negative affect, anxiety and depression as well as less positive affect and poorer quality of life. Seven latent classes (‘Low psychotic experiences’, ‘Lethargic’, ‘Blunted’, ‘Distressed’, ‘Paranormal’, ‘Distressed_grandiose’ and ‘Distressed/positive psychotic experiences’) were identified that demonstrated both dimensional differences in the number/severity of psychotic experiences and discrete differences in the patterns of reported experiences.

Conclusion

Subclinical psychotic experiences show both dimensional severity variations and discrete symptom-pattern variations across individuals. To understand and capture all interindividual variations in subclinical psychotic experiences, their number, nature and context (co-occurrence patterns) should be considered at the same time. Only some psychotic experiences may lay on a true psychopathological psychosis continuum.

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 interrelationship between schizotypy, clinical high risk for psychosis and related symptoms: Cognitive disturbances matter

Schizotypy and clinical high risk (CHR) criteria can identify individuals who are at increased risk for developing psychosis in community and patient samples. However, both approaches have rarely been combined, and very little is known about their associations. Therefore, we examined the factorial structure of CHR and related symptoms and schizotypy features as well as their interrelationship for the first time in a comprehensive approach. In a sample of 277 patients (22 ± 6 years) from two early detection services, structural equation modeling including confirmatory factor analysis was performed to test a theory-driven model using four Wisconsin Schizotypy Scales, 14 predictive basic symptoms (BS) of the Schizophrenia Proneness Instrument, and positive, negative, and disorganized symptoms from the Structured Interview for Psychosis-Risk Syndromes. The data fitted well to the six hypothesized latent factors consisting of negative schizotypy, positive schizotypy including perceptual BS, negative symptoms, positive symptoms, disorganized symptoms and cognitive disturbances. As postulated, schizotypy features were significantly associated with positive, negative and disorganized symptoms through cognitive disturbances. Additionally, positive and negative schizotypy also had a direct association with the respective symptom-domain. While the identified factorial structure corresponds well to dimensional models of schizotypy and psychoses, our model extends earlier models by indicating that schizotypy features are associated with positive, negative and disorganized symptoms directly or indirectly via subjective cognitive disturbances. This calls for more attention to subjective cognitive deficits in combination with heightened schizotypy in the early detection and intervention of psychoses - or even of an Attenuated Psychosis Syndrome.

Psychosis and Schizophrenia-Spectrum Personality Disorders Require Early Detection on Different Symptom Dimensions

Psychotic disorders and schizophrenia-spectrum personality disorders (PD) with psychotic/psychotic-like symptoms are considerably linked both historically and phenomenologically. In particular with regard to schizotypal and schizotypal personality disorder (SPD), this is evidenced by their placement in a joint diagnostic category of non-affective psychoses in the InternationaI Classification of Diseases 10th Revision, (CD-10) and, half-heartedly, the fifth edition of Diagnostic and Statistical Manual of Mental Disorders, (DSM-5). Historically, this close link resulted from observations of peculiarities that resembled subthreshold features of psychosis in the (premorbid) personality of schizophrenia patients and their biological relatives. These personality organizations were therefore called "borderline (schizophrenia)" in the first half of the 20th century. In the 1970s, they were renamed to "schizotypal" and separated from psychotic disorders on axis-I and from other PD on axis-II, including modern borderline PD, in the DSM. The phenomenological and historical overlap, however, has led to the common assumption that the main difference between psychotic disorders and SPD in particular was mainly one of severity or trajectory, with SPD representing a latent form of schizophrenia and/or a precursor of psychosis. Thus, psychosis proneness and schizotypy are often assessed using SPD questionnaires. In this perspective-piece, we revisit these assumptions in light of recent evidence. We conclude that schizotypy, SPD (and other schizophrenia-spectrum PD) and psychotic disorder are not merely states of different severity on one common but on qualitatively different dimensions, with the negative dimension being predictive of SPD and the positive of psychosis. Consequently, in light of the merits of early diagnosis, the differential early detection of incipient psychosis and schizophrenia-spectrum PD should be guided by the assessment of different schizotypy dimensions.

Association of positive, negative, and disorganized schizotypy dimensions with affective symptoms and experiences

Schizotypy offers a useful construct for investigating the etiology, development, and expression of schizophrenia-spectrum psychopathology, as well as the comorbid expression of mood and anxiety disorders across the schizophrenia spectrum. The present study examined the associations of positive, negative, and disorganized schizotypy with affective symptoms and experiences in a sample of MTurk workers and college students (n = 575). Participants completed the Multidimensional Schizotypy Scale (MSS) and measures of depression, anxiety, social phobia, hypomanic traits, and state affect. As expected, positive schizotypy was significantly associated with hypomanic traits, whereas negative schizotypy was associated with reduced positive affect and reduced hypomanic traits. Although prior research has emphasized the association of positive schizotypy with depression and anxiety, the current results demonstrate that disorganized schizotypy is more strongly associated with elevated negative affect (over-and-above positive schizotypy). As such, these findings highlight the importance of examining disorganization of affect, in addition to the cognitive-behavioral deficits traditionally associated with disorganized schizotypy. Finally, the MSS and MSS-Brief demonstrated closely comparable findings. The present results provide further support for the construct validity of the MSS and the three-factor model of schizotypy.

Prediction of prodromal symptoms and schizophrenia-spectrum personality disorder traits by positive and negative schizotypy: A 3-year prospective study

The present study extends previous cross-sectional findings by examining the predictive validity of positive and negative schizotypy in a young adult sample at a three-year follow-up. Schizotypy and schizophrenia share a comparable multidimensional structure with positive and negative dimensions being the most strongly supported factors. Previous cross-sectional and longitudinal studies employing the psychometric high-risk strategy indicated that schizotypy is a useful method for identifying risk and resilience factors for the development of schizophrenia-spectrum psychopathology. In the present study, 103 participants (77% of 134 candidate participants) were reassessed at a three-year follow-up. As hypothesized, positive schizotypy predicted psychotic-like symptoms, depression, low self-esteem, and general psychopathology. Negative schizotypy predicted emotional disturbances, schizoid personality traits, and mental health treatment during the past year. As expected, both schizotypy dimensions predicted schizotypal, paranoid, and avoidant personality traits, and impaired functioning. These longitudinal findings provide additional evidence supporting the multidimensional model of schizotypy as a valid framework for studying etiological mechanisms and trajectories of psychosis.

Episodic memory retrieval is impaired in negative schizotypy under fast response deadline

Schizotypy offers a useful, multidimensional framework for understanding the development and expression of schizophrenia-spectrum psychopathology. Nonclinically ascertained young adults who endorse positive and negative schizotypy traits exhibit similar, albeit milder, versions of the symptoms and impairment seen in schizophrenia-spectrum disorders. Previous studies have demonstrated that negative, but not positive, schizotypy is associated with impairment in free-recall, recognition, and source memory. Furthermore, these deficits appear to result from context processing deficits in negative schizotypy. However, neither positive nor negative schizotypy were associated with variation in the set size effect. The present study further examined the association with set-size effect under fast and slow response deadlines across the schizotypy continuum. We replicated the finding that the set size effect was invariant across both positive and negative schizotypy dimensions. However, negative schizotypy was associated with poorer overall recall, and the negative schizotypy by response deadline interaction revealed that negative schizotypy was differentially impaired by the speeded responding in overall memory. Despite instructions to guess on the cued-recall task, negative schizotypy was associated with increased likelihood of omission errors (failing to produce a response), whereas positive schizotypy was associated with decreased omission errors. The findings provide further support for the multidimensional model of schizotypy and previous findings that negative schizotypy is associated with impaired retrieval, especially under fast response deadlines.

Clustering of Schizotypal Features in Unaffected First-Degree Relatives of Schizophrenia Patients

Meehl conceptualized schizotypy as the phenotypic manifestations of a neural integrative defect resulting from a schizophrenia diathesis. The majority of schizotypy studies recruited subjects from the general population and revealed a multidimensional construct. This 2-phase investigation first examined the clustering of schizotypy in 194 unaffected relatives of schizophrenia patients using the Chapman Psychosis Proneness scales and then directly compared the cognitive profiles of negative schizotypal individuals and positive schizotypal individuals with schizophrenia patients and controls. In the first phase, cluster analysis categorized 194 unaffected relatives of schizophrenia patients into positive schizotypy (n = 33), negative schizotypy (n = 66), mixed schizotypy (n = 27), and low schizotypy (n = 64). Positive schizotypal participants showed more self-report pleasure experiences than negative schizotypal participants, replicating earlier cluster analytic findings. In the second phase, 27 negative schizotypal individuals, 18 positive schizotypal individuals, 19 schizophrenia patients, and 29 controls were recruited. Although the groups were matched in terms of age, gender, and IQ, they differed significantly in cognitive profiles. While schizophrenia patients exhibited the broadest cognitive impairments, negative schizotypal participants exhibited visual memory, working memory, and verbal fluency impairments, and positive schizotypal participants exhibited logical memory, visual memory, working memory, and theory-of-mind impairments. Among people with familial risk of schizophrenia, individuals exhibiting positive rather than negative schizotypal features resembled schizophrenia patients in cognitive profiles. Using the psychometric-familial method to identify schizotypy, our findings support the heterogeneity of schizotypy as well as the potential utility of the positive schizotypy dimension in genetically high-risk individuals to predict the risk of developing schizophrenia.

Odd and disorganized-Comparing the factor structure of the three major schizotypy inventories

Schizotypy is a personality-framework currently considered a comprehensive and useful construct in schizophrenia research and becoming ever more accepted within psychiatry. Thus, it is crucial to obtain a unifying and generally accepted means of its measuring. The three most commonly used psychometric schizotypy inventories, the Wisconsin Schizotypy Scales, Schizotypal Personality Questionnaire and Oxford-Liverpool Inventory of Feelings and Experiences were, however, built upon different theoretical schizotypy models, wherefore comparing results from studies that have used different inventories is difficult and sometimes questionable. Therefore, an analysis of all three inventories was conducted within the same sample of 327 healthy participants to illustrate the similarities and differences in factor structures. Results showed that findings are likely dependent on the used assessment instrument. A following item-level factor analysis was conducted to investigate the shared structure of all three inventories, in order to illustrate a framework interpretable as "common ground" between measures. This adjusted four-factor structure may be used to better aid comparisons between schizotypy-studies having used different inventories. At least, our findings illustrate the necessity of viewing individual results before the background of the theoretical framework of the respective measurement tool.

A positive-psychological intervention reduces acute psychosis-proneness

BACKGROUND

While individuals at ultra-risk for schizophrenia are characterized by high negative/disorganised but low positive schizotypy, schizophrenia patients are usually high in all three schizotypy facets. Thus, avoiding increases in positive schizotypy in ultra-high risk individuals may constitute of form of schizophrenia-prevention. A possible method of reducing positive schizotypy could be Positive-Psychological intervention (PI).

METHODS

We present results from 2 independent studies, including a 12-month follow-up from study 1, using an easy-to-perform intervention based on Positive Psychology to reduce positive schizotypy.

RESULTS

A PI can significantly and sustainably reduce positive schizotypy compared to a placebo-condition. Furthermore, our results show very high response-rates to said intervention, with responsiveness to the intervention increasing significantly with disorganised schizotypic traits.

CONCLUSIONS

As especially disorganised schizotypy is of relevance for the risk of transition from high benign schizotypy to schizophrenia and is found most closely associated to familial schizophrenia-risk and highly elevated in at-risk mental states, our results are encouraging. We suggest, thus, that positive psychology can not only reduce positive schizotypy, but may be increasingly useful with rising schizophrenia-risk and, thus, be worthy of further investigation regarding it potential in schizophrenia-prevention.

Early Motor Developmental Milestones and Schizotypy in the Northern Finland Birth Cohort Study 1966

Delayed motor developmental milestones have been reported to be associated with schizophrenia in previous studies, but no study has examined the relationship between early motor developmental milestones and schizotypy. We have examined this relationship in a prospective birth cohort.In the Northern Finland Birth Cohort 1966, data on 9 early motor developmental milestones were collected prospectively from visits to child welfare centers, and data on adult schizotypy were collected through a questionnaire (N = 4557-4674). Positive schizotypy was measured by the Perceptual Aberration Scale (PAS), negative schizotypy was measured by Physical Anhedonia Scale (PhAS) and Social Anhedonia Scale (SAS). Three related scales were included: Schizoidia Scale (SCHD), Hypomanic Personality Scale (HPS), and Bipolar II Scale (BIP2). We examined the milestone-schizotypy associations before and after excluding cases of schizophrenia from this population-based sample. Hierarchical regression analyses adjusted for covariates and separately for both genders were performed. In men, each extra month of delay in achievement of touching thumb with index finger, sitting unsupported, standing up, walking with support, or walking unsupported was associated with an increase in PAS, PhAS, or SCHD scores, or decrease in BIP2 score (P < .05). In women, each extra month of delay in achievement of turning from back to tummy was associated with an increase in PhAS and SAS scores (P < .05). Schizotypy is associated with delayed motor developmental milestones in early-life, but there is some heterogeneity with regards to types of milestones and gender. These findings suggest delayed motor development confers risk across the continuum of schizophrenia syndrome.

Assessment of Cognition and Personality as Potential Endophenotypes in the Western Australian Family Study of Schizophrenia

Phenotypic heterogeneity is a major barrier to understanding the genetic architecture underlying schizophrenia. Incorporating endophenotypes is one way to reduce heterogeneity and facilitate more powerful genetic analysis. Candidate endophenotypes require systematic assessment against endophenotype criteria, and a ranking of their potential utility for genetic analysis. In this study we assess 20 cognitive and personality measures in a sample of 127 families with at least 2 cases of schizophrenia per family (n = 535) plus a set of 30 control families (n = 121) against 4 endophenotype criteria: (a) be associated with the illness but not be a part of its diagnosis, (b) be heritable, (c) co-segregate with the illness in families, and (d) be found in unaffected relatives at a higher rate than in the general population. The endophenotype ranking score (endophenotype ranking variable [ERV]) was used to rank candidate endophenotypes based on their heritability and genetic correlation with schizophrenia. Finally, we used factor analysis to explore latent factors underlying the cognitive and personality measures. Evidence for personality measures as endophenotypes was at least equivalent to that of the cognitive measures. Factor analysis indicated that personality and cognitive traits contribute to independent latent dimensions. The results suggest for this first time that a number of cognitive and personality measures are independent and informative endophenotypes. Use of these endophenotypes in genetic studies will likely improve power and facilitate novel aetiological insights.

The Latent Taxonicity of Schizotypy in Biological Siblings of Probands With Schizophrenia

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

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".

The multidimensional schizotypy scale-brief: Scale development and psychometric properties

This article reports on the development and psychometric properties of a brief version of the Multidimensional Schizotypy Scale (MSS-B). The MSS-B contains 38 items that assess positive, negative, and disorganized schizotypy. The scale was derived from the full-length Multidimensional Schizotypy Scale, and the positive, negative, and disorganized subscales were designed to provide the same content coverage as the original subscales. Scale development involved a derivation sample (n = 6265) and a separate cross-validation sample (n = 1000), both drawn from four universities and Amazon Mechanical Turk. The MSS-B was derived using classical test theory, item response theory, and differential item functioning. The three subscales exhibited high internal-consistency reliability, good item- and model-fit, good test information functions, and expected patterns of intercorrelations and associations with neuroticism, sex, and race/ethnicity. This pattern of findings was almost identical between the derivation and cross-validation samples. Furthermore, the pattern of findings was closely comparable for MSS-B subscales and the full-length MSS subscales. The MSS-B appears to offer a promising brief measure for assessing schizotypy.

Development and psychometric properties of the Multidimensional Schizotypy Scale: A new measure for assessing positive, negative, and disorganized schizotypy

This article reports on the development of a new self-report questionnaire measure of schizotypy - the Multidimensional Schizotypy Scale (MSS). Schizotypy offers a useful and unifying construct for understanding schizophrenia-spectrum psychopathology. Questionnaire measures have been widely used to assess schizotypy and have greatly informed our understanding of the construct. However, available measures suffer from a number of limitations, including lack of a clear conceptual framework, outdated wording, unclear factor structure, and psychometric shortcomings. The MSS is based on current conceptual models and taps positive, negative, and disorganized dimensions of schizotypy. The derivation sample included 6265 participants sampled from four universities and Amazon Mechanical Turk. A separate sample of 1000 participants from these sources was used to examine the psychometric properties of the final subscales. Scale development employed classical test theory, item response theory, and differential item function methods. The positive schizotypy and negative schizotypy subscales contain 26 items each, and the disorganized schizotypy subscale contains 25 items. The psychometric properties were almost identical in the derivation and validation samples. All three subscales demonstrated good to excellent reliability, high item-scale correlations, and good item and test curve characteristics. The MSS appears to provide a promising measure for assessing schizotypy.

Schizotypy-Independent and Schizotypy-Modulated Cognitive Impairments in Unaffected First-Degree Relatives of Schizophrenia-spectrum Patients

Objective

The aim of the study was to compare the neurocognitive profile of unaffected first-degree relatives of schizophrenia patients with control individuals, controlling for different schizotypal traits.

Method

One hundred and fifteen adult unaffected first-degree relatives of schizophrenia-spectrum patients and 122 controls were tested for schizotypy with the Schizotypal Personality Questionnaire. They also underwent a thorough neurocognitive assessment with a range of tasks covering several aspects of executive functioning. Between-group differences in cognition were examined first with multivariate analysis of variance and then with a series of multivariate analyses of covariance, including the schizotypal dimensions as covariates.

Results

The relatives had higher scores on all schizotypal dimensions compared with controls and poorer planning, problem solving, strategy formation and working memory, irrespective of schizotypal traits. They also scored lower in executive working memory and verbal fluency. The difference in executive working memory was sensitive to the effects of paranoid and negative schizotypy (both dimensions abolished the between-group difference) whereas the difference in verbal fluency was sensitive only to the effects of paranoid schizotypy. Neither cognitive-perceptual nor disorganized schizotypy accounted for any differences in neurocognition between relatives and the controls.

Conclusions

Impairments in planning, problem solving, strategy formation and working memory are "core" impairments in the schizophrenia-spectrum, possibly due to high heritability effects in these functions. Impairments in executive working memory and verbal fluency are associated with paranoid and negative schizotypy, possibly due to alterations in a common fronto-temporo-parietal neural network.

Reliability, Factor Structure, and Associations With Measures of Problem Relationship and Behavior of the Personality Inventory for DSM-5 in a Sample of Italian Community-Dwelling Adolescents

In order to assess the reliability, factorial validity, and criterion validity of the Personality Inventory for DSM-5 (PID-5) among adolescents, 1,264 Italian high school students were administered the PID-5. Participants were also administered the Questionnaire on Relationships and Substance Use as a criterion measure. In the full sample, McDonald's ω values were adequate for the PID-5 scales (median ω = .85, SD = .06), except for Suspiciousness. However, all PID-5 scales showed average inter-item correlation values in the .20-.55 range. Exploratory structural equation modeling analyses provided moderate support for the a priori model of PID-5 trait scales. Ordinal logistic regression analyses showed that selected PID-5 trait scales predicted a significant, albeit moderate (Cox & Snell R² values ranged from .08 to .15, all ps < .001) amount of variance in Questionnaire on Relationships and Substance Use variables.

Emotion processing deficits in the different dimensions of psychometric schizotypy

Schizotypy refers to a personality structure indicating "proneness" to schizophrenia. Around 10% of the general population has increased schizotypal traits, they also share other core features with schizophrenia and are thus at heightened risk for developing schizophrenia and spectrum disorders. A key aspect in schizophrenia-spectrum pathology is the impairment observed in emotion-related processes. This review summarizes findings on impairments related to central aspects of emotional processes, such as emotional disposition, alexithymia, facial affect recognition and speech prosody, in high schizotypal individuals in the general population. Although the studies in the field are not numerous, the current findings indicate that all these aspects of emotional processing are deficient in psychometric schizotypy, in accordance to the schizophrenia-spectrum literature. A disturbed frontotemporal neural network seems to be the critical link between these impairments, schizotypy and schizophrenia. The limitations of the current studies and suggestions for future research are discussed.

[Schizotypal Personality Questionnaire-Brief - Likert format: Factor structure analysis in general population in France]

INTRODUCTION

The main objective of the study was to explore the factorial structure of the French version of the Schizotypal Personality Questionnaire-Brief (SPQ-B) in a Likert format, in a representative sample of the general population. In addition, differences in the dimensional scores of schizotypy according to gender and age were analyzed. As the study in the general population of schizotypal traits and its determinants has been recently proposed as a way toward the understanding of aetiology and pathophysiology of schizophrenia, consistent self-report tools are crucial to measure psychometric schizotypy. A shorter version of the widely used Schizotypal Personality Questionnaire (SPQ-Brief) has been extensively investigated in different countries, particularly in samples of students or clinical adolescents, and more recently, a few studies used a Likert-type scale format which allows partial endorsement of items and reduces the risk of defensive answers.

METHOD

A sample of 233 subjects representative of the adult population from an urban area near Paris (Créteil) was recruited using the "itinerary method". They completed the French version of the SPQ-B with a 5-point Likert-type response format (1=completely disagree; 5=completely agree). We examined the dimensional structure of the French version of the SPQ-B with a Principal Components Analysis (PCA) followed by a promax rotation. Factor selection was based on Eigenvalues over 1.0 (Kaiser's criterion), Cattell's Scree-plot test, and interpretability of the factors. Items with loadings greater than 0.4 were retained for each dimension. The internal consistency estimate of the dimensions was calculated with Cronbach's α. In order to study the influence of age and gender, we carried out a simple linear regression with the subscales as dependent variables.

RESULTS

Our sample was composed of 131 women (mean age=52.5±18.2 years) and 102 men (mean age=53±18.1 years). SPQ-B Likert total scores ranged from 22 to 84 points (mean=43.6±13). Factor analysis resulted in a 3-factor solution that explained 47.7% of the variance. Factor 1 (disorganized; 10 items) included items related to "odd behavior", "odd speech", as well as "social anxiety", one item of "constricted affect" and one item of "ideas of reference". Factor 2 (interpersonal; 7 items) included items related to "no close friends", "constricted affect", and three of the items of "suspiciousness". Factor 3 (cognitive-perceptual; 5 items) included items related to "ideas of reference", "magical thinking", "unusual perceptual experiences" and one item of "suspiciousness". Coefficient α for the three subscales and total scale were respectively 0.81, 0.81, 0.77 and 0.88. We found no differences in total schizotypy and the three dimensions scores according to age and sex.

CONCLUSION

Factor analysis of the French version of the SPQ-B in a Likert format confirmed the three-factor structure of schizotypy. We found a pure cognitive perceptual dimension including the most representative positive features. As expected, "Suspiciousness" subscale is included in both positive and negative dimensions, but mainly in the negative dimension. Surprisingly, "social anxiety" subscale is included in the disorganized dimension in our analysis. The SPQ-B in a Likert format demonstrated good internal reliability for both total and subscales scores. Unlike previous published results, we did not find any influence of age or gender on schizotypal dimensions.

Increased distractibility in schizotypy: Independent of individual differences in working memory capacity?

Individuals with schizophrenia typically show increased levels of distractibility. This has been attributed to impaired working memory capacity (WMC), since lower WMC is typically associated with higher distractibility, and schizophrenia is typically associated with impoverished WMC. Here, participants performed verbal and spatial serial recall tasks that were accompanied by to-be-ignored speech tokens. For the few trials wherein one speech token was replaced with a different token, impairment was produced to task scores (a deviation effect). Participants subsequently completed a schizotypy questionnaire and a WMC measure. Higher schizotypy scores were associated with lower WMC (as measured with operation span, OSPAN), but WMC and schizotypy scores explained unique variance in relation to the mean magnitude of the deviation effect. These results suggest that schizotypy is associated with heightened domain-general distractibility, but that this is independent of its relationship with WMC.

The relation between schizotypy and early attention to rejecting interactions: The influence of neuroticism

OBJECTIVES

Schizotypy relates to rejection sensitivity (anxiety reflecting an expectancy of social exclusion) and neuroticism (excessive evaluation of negative emotions). Positive schizotypy (e.g., perceptual aberrations and odd beliefs) and negative schizotypy (e.g., social and physical anhedonia) could relate to altered attention to rejection because of neuroticism.

METHODS

Forty-one healthy individuals were assessed on positive and negative schizotypy and neuroticism, and event-related potentials during rejecting, accepting and neutral scenes. Participants were categorised into high, moderate and low neuroticism groups. Using temporo-spatial principal components analyses, P200 (peak latency = 290 ms) and P300 amplitudes (peak latency = 390 ms) were measured, reflecting mobilisation of attention and early attention, respectively.

RESULTS

Scalp-level and cortical source analysis revealed elevated fronto-parietal N300/P300 amplitude and P200-related dorsal anterior cingulate current density during rejection than acceptance/neutral scenes. Positive schizotypy related inversely to parietal P200 amplitude during rejection. Negative schizotypy related positively to P200 middle occipital current density. Negative schizotypy related positively to parietal P300, where the association was stronger in high and moderate, than low, neuroticism groups.

CONCLUSIONS

Positive and negative schizotypy relate divergently to attention to rejection. Positive schizotypy attenuates, but negative schizotypy increases rejection-related mobilisation of attention. Negative schizotypy increases early attention to rejection partly due to elevated neuroticism.