The association of schizotypal traits with Prepulse Inhibition: a double approach exploration.

Introduction: According to the fully-dimensional approach, schizotypy is a personality trait present in the population in a continuous manner while the quasi-dimensional approach emphasises its extreme presentations. In this study we examined the relationship between sensorimotor gating, a core risk-index of the schizophrenia-spectrum, and four schizotypal factors in a dimensional-wise and a dichotomising-wise approach. Methods: Two-hundred and eighty-three participants were assessed with the Schizotypal Personality Questionnaire and were tested for Prepulse Inhibition (PPI). Associations between the schizotypal factors and startle measures were examined with stepwise regressions (dimensional-wise approach). Individuals in the lower 20% or the upper 20% for each schizotypal factor were identified and between-group comparisons were conducted (dichotomising-wise approach). Results: We found that with both approaches, only high paranoid or negative schizotypy were associated with reduced PPI. The low negative schizotypy group had prolonged onset and peak latencies, indicating that prolonged stimulus detection accompanies superior sensorimotor gating in this group. Conclusions: The findings suggest that although differentiating the effects of the various schizotypal factors is primary, the approach employed is secondary. The study also adds evidence in the literature supporting PPI as a useful endophenotypic marker of the schizophrenia-spectrum and highlights the contribution of specific aspects of schizotypy.

Exploring the Relationship Between Schizotypal Traits and Dispositional Mindfulness From a Network Perspective.

Schizotypy has been associated with impairment in social cognition (e.g., emotional processing, social perception, Theory of Mind). To our knowledge, no study has investigated these processes in terms of dispositional mindfulness. This study aimed to use network theory to explore the relationship between dispositional mindfulness dimensions and schizotypal traits. Participants were 1572 college students who completed the Five Facet Mindfulness Questionnaire-Short Form (FFMQ-SF) and the Schizotypal Personality Questionnaire-Brief (SPQ-B). We first estimated a Gaussian Graphical Model including the FFMQ-SF and the SPQ-B dimensions. We then computed centrality indices and predictability, and we finally conducted a bootstrapping procedure to assess the accuracy of edge weights and the stability of the centrality indices. Describing was strongly and negatively related to interpersonal schizotypy. Acting with awareness and nonjudgment shared negative edges with interpersonal schizotypy. These results provide potential keys to understand alexithymia, decreased sense of self-agency, and emotion regulation in schizotypy.

Is schizotypic maternal personality linked to sensory gating abilities during infancy?

Schizotypy is a personality dimension within the general population elevated among schizophrenia-spectrum patients and their first-degree relatives. Sensory gating is the pre-attentional habituation of responses distinguishing between important and irrelevant information. This is measured by event-related potentials, which have been found to display abnormalities in schizophrenic disorders. The current study investigated whether 6-month-old infants of mothers with schizotypic traits display sensory gating abnormalities. The paired-tone paradigm: two identical auditory tones (stimulus 1 and stimulus 2) played 500 ms apart, was used to probe the selective activation of the brain during 15-minutes of sleep. Their mothers completed the Oxford and Liverpool Inventory of Feelings and Experiences-Short Form as an index of schizotypy dimensionality, categorized into: infants of control, and infants of schizotypic, mothers. The findings revealed that although the infants' P50 components displayed significant differences between stimulus 1 and stimulus 2 in the paired-tone paradigm, there was no clear difference between infants of schizotypic and infants of control mothers. In contrast, all mothers displayed significant differences between stimulus 1 and stimulus 2, as observed in the infants, but also significant differences between their sensory gating ability correlated with schizotypy dimensionality. These findings are consistent with sensory processes, such as sensory gating, evidencing impairment in schizophrenia-spectrum disorders. The present research supports the idea that first-degree relatives of individuals who identify on this spectrum, within the sub-clinical category, do not display the same deficit at 6 postnatal months of age.

Spirituality, dimensional autism, and schizotypal traits: The search for meaning.

The relationships of spirituality with human social cognition, as exemplified in autism spectrum and schizophrenia spectrum cognitive variation, remain largely unstudied. We quantified non-clinical levels of autism spectrum and schizotypal spectrum traits (using the Autism Quotient and the Schizotypal Personality Questionnaire-Brief Revised) and dimensions of spirituality (using the Hardt Spirituality Questionnaire) in a large sample of undergraduate students. We tested in particular the hypothesis, based on the diametrical model of autism and psychosis, that autism should be negatively associated, and positive schizotypal traits should be positively associated, with spirituality. Our primary findings were threefold. First, in support of the diametric model, total Spirituality score was significantly negatively correlated with total Autism Quotient score, and significantly positively correlated with Positive Schizotypal traits (the Schizotypal Personality Cognitive-Perceptual subscale), as predicted. Second, these associations were driven mainly by opposite patterns regarding the Search for Meaning Spirituality subscale, which was the only subscale that was significantly negatively associated with autism, and significantly positively associated with Positive Schizotypal traits. Third, Belief in God was positively correlated with Positive Schizotypal traits, but was uncorrelated with autism traits. The opposite findings for Search for Meaning can be interpreted in the contexts of well-supported cognitive models for understanding autism in terms of weak central coherence, and understanding Positive Schizotypal traits in terms of enhanced salience.

Segregating polymorphism in the NMDA receptor gene GRIN2A, schizotypy, and mental rotation among healthy individuals.

Common alleles associated with psychiatric disorders are often regarded as deleterious genes that influence vulnerability to disease, but they may also be considered as mediators of variation in adaptively structured cognitive phenotypes among healthy individuals. The schizophrenia-associated gene GRIN2A (glutamate ionotropic receptor NMDA type subunit 2a) codes for a protein subunit of the NMDA (N-methyl-D-aspartate) receptor that underlies central aspects of human cognition. Pharmacological NMDA blockage recapitulates the major features of schizophrenia in human subjects, and represents a key model for the neurological basis of this disorder. We genotyped two functional GRIN2A polymorphisms in a large population of healthy individuals who were scored for schizotypy and mental imagery/manipulation (the mental rotation test). Rare-allele homozygosity of the promoter microsatellite rs3219790 was associated with high total schizotypy (after adjustment for multiple comparisons) and with enhanced mental rotation ability (nominally, but not after adjustment for multiple comparisons), among males. These findings provide preliminary evidence regarding a genetic basis to previous reports of enhanced mental imagery in schizophrenia and schizotypy. The results also suggest that some schizophrenia-related alleles may be subject to cognitive tradeoffs involving both positive and negative effects on psychological phenotypes, which may help to explain the maintenance of psychiatric-disorder risk alleles in human populations.

Well-being in schizotypy: The effect of subclinical psychotic experiences / Bienestar en esquizotipia: efecto de las experiencias psicóticas atenuadas

BACKGROUND: Schizotypy is a multidimensional construct that includes positive, negative, and disorganized dimensions. The healthy schizotypal model suggests that positive schizotypal features could be associated with better psychological functioning. The aim of this study was to analyze whether schizotypal features are associated with subjective and psychological well-being, and consider whether psychotic-like experiences affect well-being. METHOD: These relationships were investigated in two hundred non-clinical Spanish adults (mean age = 34.80, S.D. = 14.20). RESULTS: Negative schizotypal features were associated with lower well-being, whereas positive schizotypal features were related with greater well-being. Individuals with subclinical psychotic experiences scored lower for psychological well-being than individuals without these experiences. CONCLUSIONS: The study suggests that some positive features may be beneficial for well-being while others are associated with lower well-being

ANTECEDENTES: Bienestar en esquizotipia: efecto de las experiencias psicóticas atenuadas. Antecedentes: la esquizotipia es un constructo multidimensional que incluye las dimensiones positiva, negativa y de desorganización cognitiva. El modelo de esquizotipia saludable sugiere que los rasgos esquizotípicos positivos podrían estar asociados con un mejor funcionamiento psicológico. El objetivo de este estudio fue analizar si los rasgos esquizotípicos se asociaban con el bienestar subjetivo y psicológico, y si las experiencias psicóticas atenuadas afectaban al bienestar. Método: en el estudio participaron 200 adultos españoles (edad media = 34.80, S.D. = 14.20). Resultados: los rasgos esquizotípicos negativos se asociaron con bajo bienestar y los positivos con mayor bienestar. Los individuos con experiencias psicóticas atenuadas obtuvieron puntuaciones más bajas en bienestar psicológico que las personas sin estas experiencias. Conclusiones: el estudio sugiere que ciertos rasgos positivos de la esquizotipia pueden ser beneficiosos para el bienestar, mientras que otros pueden perjudicarlo

Well-being in schizotypy: The effect of subclinical psychotic experiences.

BACKGROUND: Schizotypy is a multidimensional construct that includes positive, negative, and disorganized dimensions. The healthy schizotypal model suggests that positive schizotypal features could be associated with better psychological functioning. The aim of this study was to analyze whether schizotypal features are associated with subjective and psychological well-being, and consider whether psychotic-like experiences affect well-being. METHOD: These relationships were investigated in two hundred non-clinical Spanish adults (mean age = 34.80, S.D . = 14.20). RESULTS: Negative schizotypal features were associated with lower well-being, whereas positive schizotypal features were related with greater well-being. Individuals with subclinical psychotic experiences scored lower for psychological well-being than individuals without these experiences. CONCLUSIONS: The study suggests that some positive features may be beneficial for well-being while others are associated with lower well-being.

The relationship between schizotypal facets and conspiracist beliefs via cognitive processes.

This study sought to replicate previous work showing relationships between components of schizotypy and conspiracist beliefs, and extend it by examining the mediating role of cognitive processes. An international online sample of 411 women and men (mean age = 35.41 years) completed measures of the schizotypal facets of Odd Beliefs or Magical Thinking and Ideas of Reference, conspiracist beliefs, and cognitive processes related to need for cognition, analytic thinking, and cognitive insight. Path analysis confirmed the associations between both schizotypal facets and conspiracist beliefs in the present sample. Confirmatory evidence was found for the association between analytic thinking and conspiracist beliefs, and results also suggested an association between cognitive insight and conspiracist beliefs. Cognitive insight also mediated the link between Odd Beliefs or Magical Thinking and Ideas of Reference with conspiracist beliefs. However, analytic thinking provided a mediating link to conspiracy ideation for Odd Beliefs or Magical Thinking and not Ideas of Reference. Finally, there was an association between Odd Beliefs or Magical Thinking and need for cognition, but this path did not extend to conspiracist beliefs. These results suggest possible mediating roles for analytic thinking and self-certainty between schizotypy and conspiracist beliefs.

Enhanced mental imagery and intact perceptual organization in schizotypal personality disorder.

According to a widely held view, psychotic disorders such as schizophrenia are characterized by a vague boundary between the perception of the external world and the inner imagery of persons, objects, and events. In this study, we addressed the perception-imagery debate in schizotypal personality disorder (SPD). Thirty individuals with SPD and 30 matched healthy subjects completed a lateral masking task. Participants were asked to detect a low-contrast Gabor patch flanked by two collinear Gabor masks. In the perceptual task, the masks were physically present, whereas in the imagery task, participants only imagined the masks. By applying a binocular rivalry paradigm, we also measured the imagery priming effect. Results revealed that, in the perceptual task, collinear masks similarly decreased contrast threshold in SPD and controls. In the imagery task, contrast threshold reduction (facilitation by the imagined masks) was more pronounced in SPD relative to the controls. In the binocular rivalry paradigm, individuals with SPD showed higher imagery priming effects as compared to healthy controls. Enhanced imagery was not related to schizotypal traits. These results indicate intact early visual perception and heightened imagery in SPD, which may be a trait marker of unusual experiences without psychotic disorganization.

The PCSK6 gene is associated with handedness, the autism spectrum, and magical ideation in a non-clinical population.

Common polymorphisms in the gene PCSK6, whose protein product mediates the development of brain and body asymmetry through the NODAL pathway, have recently been associated with handedness in three studies, making it a key candidate gene for understanding the developmental and expression of human lateralization. We tested the hypothesis that the PCSK6 VNTR polymorphism rs1053972 influences the expression of handedness and aspects of dimensional schizotypy and autism. For a sample of 709 healthy individuals, rs1053972 genotype was significantly associated with categorical measures of handedness, and with dimensional handedness in subsets of the population with high schizotypy and magical ideation or a lack of strong right-handedness. Both findings showed evidence of stronger or exclusive effects among females, compared to males. Genotypes of PCSK6 also showed significant sex-limited associations with magical ideation, a component of positive schizotypal cognition measured using the Schizotypal Personality Questionnaire, and total autism score, measured using the Autism Spectrum Quotient. These results partially replicate previous studies on effects of PCSK6 rs1053972 genetic variation on handedness phenotypes, link the PCSK6 gene with the dimensional expression of neurodevelopmental conditions in healthy individuals, and show that associations of this gene with handedness and psychological phenotypes exhibit evidence of sex-limited effects.

The Janus face of schizotypy: enhanced spiritual connection or existential despair?

It has been asserted that schizotypy has a negative relationship with subjective well-being. By employing a multidimensional measure of spiritual well being with 400 British College students we report a more complex relationship. The Multidimensional Inventory for Religious/Spiritual Well-Being and Schizotypal Personality Questionnaire-Brief Version were used and analysis made use of Canonical Correlational Analysis. Results suggested that two distinct relationships emerged between schizotypy and spirituality. First, a positive association between cognitive/perceptual features of schizotypy and spiritual connectedness emerged. Second a more global negative relationship between feelings of spiritual isolation and despair was found for all aspects of schizotypy. These findings challenge the previous literature based on one-dimensional subjective well being measures which have found only a negative relationship. However, the positive association between connectedness and cognitive-perceptual aspects of schizotypy raises import questions about the possible benefit of certain types of schizotypal experience.

Personality disorders and spirituality.

PURPOSE OF REVIEW: In order to consider findings about the relationship between spirituality, religiosity and personality disorders, recent research was reviewed and emerging patterns in the latest findings were explored. RECENT FINDINGS: Within the diagnostic category of personality disorders, recent research into the role of spirituality has focused on schizotypy and borderline personality traits and aspects of 'control' relating to antisocial personality disorder. Although the number of studies is quite limited, this review has highlighted an interesting pattern emerging from recent studies that suggests that, while overall psychological well being has previously been reported as low, spiritual well being remains high in studies of personality focusing on schizotypy and borderline personality traits. SUMMARY: The positive link between religious and spiritual well being and mental health has been corroborated by a number of studies. This review of recent research has identified emerging trends suggesting that the dimensions of religious and spiritual well being remain high for individuals displaying schizotypy and borderline personality traits, and is not as reduced as general well being in individuals diagnosed with personality disorders. Although much work remains to be conducted with individuals diagnosed with personality disorders, spirituality appears to be an interesting area to explore clinically.

Magical ideation, schizotypy and the impact of emotions.

Research indicates that emotions can interfere with basic cognitive functions such as attention and memory, and that schizotypal traits may be related to vulnerability to such interference, The schizotypal trait magical ideation, expressed as illogicality and tendencies to endorse peculiar or eccentric beliefs, has been reported to be related to impairments in social cognitive functioning as well risk for psychosis. This study examined the impact of emotionally arousing films on heart rate activity, affect ratings, and working memory. Participants were university students. Results indicated that high magical ideation scores were associated with impairments in short-term memory, higher post-film affect ratings, decreased clarity of affect awareness, and increased heart rate in response to emotionally arousing films. These results suggest that magical ideation may be an indicator of lower thresholds for arousal and increased vulnerability to disruption of cognitive processes by situations that elicit strong emotions.

An evaluation of P50 paired-click methodologies.

The utility of P50 paired-click measures is limited by their unestablished reliability, unknown effects of time, and long protocol. This study measured within-session reliability, temporal course, effect of varying interpair interval (IPI), and peak definition and ratio calculation methods on P50 paired-click measures in healthy participants. Results indicate higher reliability for difference (ICC=.72) than ratio (ICC=.44) method; when P50 peaks are defined as baseline-to-peak than peak-to-peak; time-related changes; and comparable P50 paired-click measures at long (9 s) and short (3-7 s) IPIs. After controlling for time effects, P50 paired-click measures are relatively reliable within-session and are best measured using the difference method and defined as baseline-to-peak amplitude; time effects must be taken into account when measuring P50 paired-click measures in a long paradigm; and IPI can be shortened in studies with healthy samples.

Effect of a context of concrete and abstract words on hallucinatory content in individuals scoring high in schizotypy.

The present study examined the occurrence and content of auditory hallucinatory experiences in 41 non-clinical participants scoring high or low on the Oxford-Liverpool Inventory of Feelings and Experiences (brief version; OLIFE-B) measure of schizotypy. Participants listened to 10 1-min recordings of white noise, some of which contained embedded concrete or abstract words, and were asked to record the words that they had heard. High scorers on the unusual experiences (UE) scale of the OLIFE-B reported hearing more words, not actually present, relative to low scorers on that measure. In addition, high UE scorers showed a bias toward making hallucinatory reports of an abstract type over a concrete type. These results suggest a bias toward more auditory hallucinatory reports in high scorers in schizotypy, and particularly to those of an abstract type.

Differential associations between schizotypy facets and emotion traits.

Although emotional deficits in schizotypy have been reported, the exact nature of these deficits is not well understood. The goal of the current research was to further differentiate possible emotion deficits in schizotypy. In the current study, individuals with elevated social anhedonia (SocAnh; n=54) and elevated perceptual aberration/magical ideation (PerMag; n=27) were compared to control participants (n=304) on measures of attention to either positive or negative affect, level of anticipatory versus consummatory pleasure, and on the influence of negative mood on judgment of future risk. SocAnh was associated with decreased attention to positive emotions. At the same time, SocAnh was associated with both decreased anticipatory and decreased consummatory pleasure. In addition, in contrast to the other groups, there was no association in the SocAnh group between current negative mood and performance on a judgment task. In contrast to SocAnh, PerMag was associated with increased attention to negative emotions. Overall, these results suggest that SocAnh is associated with decreased attention to and experience of positive emotions and that PerMag is associated with increased attention to negative emotions.

Cannabis and psychometrically-defined schizotypy: use, problems and treatment considerations.

Cannabis use is associated with onset of psychosis in individuals vulnerable for developing schizophrenia-spectrum disorders. The present study addressed three knowledge gaps pertaining to this issue: 1) clarifying the incidence of cannabis use in schizotypal individuals, 2) examining how cannabis use is related to psychosocial and physiological problems in schizotypy and interest in treatment, and 3) examining how cannabis use is associated with positive, negative and disorganization features of schizotypy. Scores from a measure of schizotypal traits were used to trichotomize 1665 young adults into schizotypy (top 5% of scorers), non-schizotypy (bottom 50% of scorers) and "unconventional" (scorers within the 50th to 85th percentile) groups. Nearly a quarter of the schizotypy group endorsed cannabis use at least weekly, a rate nearly two to four times that of the other groups. The schizotypy group also reported a much greater frequency of cannabis-related problems compared to the other groups. Despite this, interest in treatment for cannabis use in the schizotypy group was not elevated. Interestingly, 85% of individuals in the schizotypy group reported interest in psychological/psychiatric treatment more generally. Cannabis use was not associated with abnormal patterns of positive or disorganized schizotypy traits in the schizotypy group relative to the other groups. However, cannabis use was associated with lower severity of negative traits. Implications of these results are discussed.

Correlation of individual differences in schizotypal personality traits with amphetamine-induced dopamine release in striatal and extrastriatal brain regions.

OBJECTIVE: Schizotypal personality traits are associated with schizophrenia spectrum disorders, and individuals with schizophrenia spectrum disorders demonstrate increased dopamine transmission in the striatum. The authors sought to determine whether individual differences in normal variation in schizotypal traits are correlated with dopamine transmission in the striatum and in extrastriatal brain regions. METHOD: Sixty-three healthy volunteers with no history of psychiatric illness completed the Schizotypal Personality Questionnaire and underwent positron emission tomography imaging with [(18)F]fallypride at baseline and after administration of oral d-amphetamine (0.43 mg/kg). Dopamine release, quantified by subtracting each participant's d-amphetamine scan from his or her baseline scan, was correlated with Schizotypal Personality Questionnaire total and factor scores using region-of-interest and voxel-wise analyses. RESULTS: Dopamine release in the striatum was positively correlated with overall schizotypal traits. The association was especially robust in the associative subdivision of the striatum. Voxel-wise analyses identified additional correlations between dopamine release and schizotypal traits in the left middle frontal gyrus and left supramarginal gyrus. Exploratory analyses of Schizotypal Personality Questionnaire factor scores revealed correlations between dopamine release and disorganized schizotypal traits in the striatum, thalamus, medial prefrontal cortex, temporal lobe, insula, and inferior frontal cortex. CONCLUSIONS: The association between dopamine signaling and psychosis phenotypes extends to individual differences in normal variation in schizotypal traits and involves dopamine transmission in both striatal and extrastriatal brain regions. Amphetamine-induced dopamine release may be a useful endophenotype for investigating the genetic basis of schizophrenia spectrum disorders.

Meta-analysis of medical and non-medical treatments of the prodromal phase of psychotic illness in at-risk mental states.

INTRODUCTION: there are now many existing studies which assess the treatments available for 'at risk mental states', as patients who are believed to be in the prodromal phase of psychotic illness are referred to. However, concerns regarding side effects of possible treatments remain. We here conduct a meta-analysis of the studies available up to October 2010. The aim of this study is to decide what would be the best treatment for 'at high risk patients'. RESULTS: all the available studies examining potential treatments during the prodromal phase of psychotic illness were collected. They all showed comparable efficacy, which reached statistical significance, excluding the one study using olanzapine, which in fact 'tended towards significance'. DISCUSSION: treatments appear promising but a balance needs to be kept between adverse events and effectiveness of preventing psychosis. CONCLUSION: it is necessary to search further for treatments in order to identify effective treatments with fewer adverse side effects in this phase of psychotic illness.

Increased temporal variability of auditory event-related potentials in schizophrenia and Schizotypal Personality Disorder.

Previous studies suggest that deficits in neural synchronization and temporal integration are characteristic of schizophrenia. These phenomena have been rarely studied in SPD, which shares phenomenological and genetic similarities with schizophrenia. Event-related potentials (ERPs) were obtained using an auditory oddball task from 21 patients with schizophrenia, 19 subjects with SPD and 19 healthy control subjects. Inter-trial coherence (ITC) and event-related spectral perturbation (ERSP) were measured across trials to target tones using time-frequency analysis. ITC measures phase locking or consistency, while ERSP measures changes in power relative to baseline activity. P300 latency and amplitude were also measured from the averaged ERP to target tones. In the time-frequency analysis, subjects with SPD showed intact power but a deficit in the ITC in delta and theta frequencies compared to control subjects. Patients with schizophrenia showed deficits for both ERSP and ITC in the delta and theta frequencies. While patients with schizophrenia showed reduced P300 amplitude and delayed latency for averaged ERPs, subjects with SPD did not differ from either group. Synchronization or timing abnormalities may represent a biomarker for schizophrenia spectrum disorders, and contribute to aberrant perceptual and cognitive integration.