Factor Analysis Demonstrates a Common Schizoidal Phenotype within Autistic and Schizotypal Tendency: Implications for Neuroscientific Studies.
ABSTRACT: Behavioral and cognitive dysfunction, particularly social and communication impairments, are shared between autism and schizophrenia spectrum disorders, while evidence for a diametric autism-positive schizophrenia symptom profile is inconsistent. We investigated the shared phenotype at a personality trait level, particularly its resemblance to schizoid personality disorder, as well as differential aspects of the autism-schizophrenia model. Items of the autism spectrum quotient (AQ) and schizotypal personality questionnaire (SPQ) were pseudo-randomly combined, and were completed by 449 (162 male, 287 female) non-clinical participants aged 18-40. A factor analysis revealed three factors; the first represented a shared social disorganization phenotype, the second reflected perceptual oddities specific to schizotypy while the third reflected social rigidity specific to autism. The AQ and SPQ were strongly correlated with Factor 1 (AQ: r?=?0.75, p?
Project description:BACKGROUND:Anomalies in visual and auditory perception represent an important aspect of the symptomatic manifestation of schizophrenia (ScZ). However, there are currently no instruments available that allow the assessment of the full range of auditory and visual abnormalities using a self-report measure. METHODS:We developed the 85-item Audio-Visual Abnormalities Questionnaire (AVAQ) to assess abnormalities in auditory and visual processing. The AVAQ was validated in an online-sample of 355 healthy participants to establish the factorial structure, internal consistency and reliability of the instrument. In addition, participants completed the Autism-Spectrum Quotient (AQ) and the Schizotypal Personality Questionnaire (SPQ) to establish convergent validity regarding autistic and schizotypal traits. RESULTS:High internal consistency was observed for the total AVAQ-scale (??=?0.99) as well as for the visual (??=?0.98), auditory (??=?0.96) and the audio-visual subscales (??=?0.83). Principal component analyses demonstrated one factor comprising 78 items. The AVAQ was positively correlated with the SPQ (r?=?0.69, p?<?.001) as well as the AQ (r?=?0.38, p?<?.001). Correlations with the SPQ were highest for unusual perceptual experiences (r?=?0.72, p?<?.001) and lowest for social anxiety (r?=?0.30, p?<?.001). CONCLUSION:The AVAQ demonstrated excellent reliability, internal consistency and construct validity. Accordingly, the instrument could be useful for characterizing sensory dysfunctions across the schizophrenia spectrum that could guide interventions as well as aid the development of biomarkers.
Project description:Individuals with autism spectrum disorder and individuals with schizophrenia have impaired social and communication skills. They also have altered auditory perception. This study investigated autistic traits and schizotypy in a non-clinical population as well as the excitation-inhibition (EI) balance in different brain regions and their auditory multistable perception. Thirty-four healthy participants were assessed by the Autism-Spectrum Quotient (AQ) and Schizotypal Personality Questionnaire (SPQ). The EI balance was evaluated by measuring the resting-state concentrations of glutamate-glutamine (Glx) and ?-aminobutyric acid (GABA) in vivo by using magnetic resonance spectroscopy. To observe the correlation between their traits and perception, we conducted an auditory streaming task and a verbal transformation task, in which participants reported spontaneous perceptual switching while listening to a sound sequence. Their AQ and SPQ scores were positively correlated with the Glx/GABA ratio in the auditory cortex but not in the frontal areas. These scores were negatively correlated with the number of perceptual switches in the verbal transformation task but not in the auditory streaming task. Our results suggest that the EI balance in the auditory cortex and the perceptual formation of speech are involved in autistic traits and schizotypy.
Project description:<h4>Background</h4>The autism and schizophrenia spectra overlap to a large degree in the social and interpersonal domains. Similarly, abnormal excitatory glutamate and inhibitory ?-aminobutyric acid (GABA) neurotransmitter concentrations have been reported for both spectra, with the interplay of these neurotransmitters important for cortical excitation to inhibition regulation. This study investigates whether these neurotransmitter abnormalities are specific to the shared symptomatology, and whether the degree of abnormality increases with increasing symptom severity. Hence, the relationship between the glutamate/GABA ratio and autism and schizophrenia spectrum traits in an unmedicated, subclinical population was investigated.<h4>Methods</h4>A total of 37 adults (19 female, 18 male) aged 18-38 years completed the Autism Spectrum Quotient (AQ) and Schizotypal Personality Questionnaire (SPQ), and participated in the resting state proton magnetic resonance spectroscopy study in which sequences specific for quantification of glutamate and GABA+ concentration were applied to a right and left superior temporal voxel.<h4>Results</h4>There were significant, moderate, positive relationships between right superior temporal glutamate/GABA+ ratio and AQ, SPQ and AQ+SPQ total scores (p<0.05), SPQ subscales Social Anxiety, No Close Friend, Constricted Affect, Odd Behaviour, Odd Speech, Ideas of Reference and Suspiciousness, and AQ subscales Social Skills, Communication and Attention Switching (p<0.05); increased glutamate/GABA+ coinciding with higher scores on these subscales. Only the relationships between glutamate/GABA+ ratio and Social Anxiety, Constricted Affect, Social Skills and Communication survived multiple comparison correction (p< 0.004). Left superior temporal glutamate/GABA+ ratio reduced with increasing restricted imagination (p<0.05).<h4>Conclusion</h4>These findings demonstrate evidence for an association between excitatory/inhibitory neurotransmitter concentrations and symptoms that are shared between the autism and schizophrenia spectra.
Project description:INTRODUCTION:Schizophrenia and schizotypal personality disorder (SPD) lie on a single spectrum of mental illness and converging evidence suggests similarities in the etiology of the 2 conditions. However, schizotypy is a heterogeneous facet of personality in the healthy population and so may be seen as a bridge between health and mental illness. Neural evidence for such a continuity would have implications for the characterization and treatment of schizophrenia. Based on our previous work identifying a relationship between symptomology in schizophrenia and abnormal movement-induced electrophysiological response (the post-movement beta rebound [PMBR]), we predicted that if subclinical schizotypy arises from similar neural mechanisms to schizophrenia, schizotypy in healthy individuals would be associated with reduced PMBR. METHODS:One-hundred sixteen participants completed a visuomotor task while their neural activity was recorded by magnetoencephalography. Partial correlations were computed between a measure of PMBR extracted from left primary motor cortex and scores on the Schizotypal Personality Questionnaire (SPQ), a self-report measure of schizotypal personality. Correlations between PMBR and SPQ factor scores measuring cognitive-perceptual, interpersonal and disorganization dimensions of schizotypy were also computed. Effects of site, age, and sex were controlled for. RESULTS:We found a significant negative correlation between total SPQ score and PMBR. This was most strongly mediated by variance shared between interpersonal and disorganization factor scores. CONCLUSION:These findings indicate a continuum of neural deficit between schizotypy and schizophrenia, with diminution of PMBR, previously reported in schizophrenia, also measurable in individuals with schizotypal features, particularly disorganization and impaired interpersonal relations.
Project description:The Schizotypal Personality Questionnaire (SPQ) is one of the most widely used screening tools for schizotypy in adults. The Schizotypal Personality Questionnaire-Child version (SPQ-C) was recently developed to assess schizotypy in children and has a similar three-factor structure to the adult SPQ (i.e., Cognitive-Perceptual, Interpersonal-Affective, and Disorganization). However, few studies to date have reported on the psychometric properties and the usefulness of the SPQ-C in Eastern populations, including Mainland China. This study presents the first psychometric assessment of the Chinese SPQ-C in Mainland China. Exploratory factor analysis and confirmatory factor analysis were used to assess the factor structure of the SPQ-C in 1668 children (M?=?12.10, SD?=?0.60 years) from the China Jintan Child Cohort Study. Our findings document a three-factor structure and partial measurement invariance across residential location and gender, replicating the psychometric properties of the SPQ-C in English. The Chinese SPQ-C further correlates with standard behavioral problems (i.e., Child Behavior Checklist, Youth Self-Report and Teacher Report Form), demonstrating construct validity and utility as a child psychopathology assessment tool. Our findings provide the first robust psychometric evidence for a three-factor structure of the Chinese SPQ-C in a large Mainland Chinese sample, and suggest that the SPQ-C is suitable as a screening tool for schizotypy in community children who may be at risk for behavioral problems and later psychosis.
Project description:Several genetic mechanisms have been proposed for the variability of the Klinefelter syndrome (KS) phenotype such as the parent-of-origin of the extra X chromosome. Parent-of-origin effects on behavior in KS can possibly provide insights into X-linked imprinting effects on psychopathology that may be extrapolated to other populations. Here, we investigated whether the parent-of-origin of the supernumerary X chromosome influences autistic and schizotypal symptom profiles in KS.Parent-of-origin of the X chromosome was determined through analysis of the polymorphic CAG tandem repeat of the androgen receptor gene. Autistic traits (Autism Diagnostic Interview-Revised) were measured in a younger KS sample (n = 33) with KS and schizotypal traits (Schizotypal Personality Questionnaire) were assessed in an older KS sample (n = 43). Scale scores on these questionnaires were entered in statistical analyses to test parent-of-origin effects.The results show that parent-of-origin of the X chromosome is reflected in autistic and schizotypal symptomatology. Differences were shown in the degree of both schizotypal and autistic symptoms between the parent-of-origin groups. Furthermore, the parent-of-origin could be correctly discriminated in more than 90% of subjects through Autism Diagnostic Interview-Revised scales and in around 80% of subjects through Schizotypal Personality Questionnaire scales.These findings point to parent-of-origin effects on psychopathology in KS and indicate that imprinted X chromosomal genes may have differential effects on autistic and schizotypal traits. Further exploration of imprinting effects on psychopathology in KS is needed to confirm and expand on our findings.
Project description:Given the common use of self-report questionnaires to assess schizotypy in personality pathology and schizophrenia research, it is important to determine the concordance between self-report and clinician ratings. 250 individuals with schizotypal personality disorder (SPD) and 116 community controls (CTR) were assessed on schizotypal traits using a clinical interview, the Structured Interview for DSM-IV Personality disorders (SIDP), and a self-report questionnaire, the Schizotypal Personality Questionnaire (SPQ). Ordinal logistic regressions examined concordance between self-reported and clinician-rated scores in CTR and SPD separately. Analyses of variance examined how the SPQ performed on differentiating between CTR with low schizotypy, CTR with high schizotypy, and SPD. For both CTR and SPD, higher SPQ subscale scores were significantly associated with higher clinician ratings on the respective SIDP items for the Ideas of Reference, Magical Thinking, Unusual Perceptual Experience, Suspiciousness, and Social Anxiety items, but not the Odd Speech or Limited Affect items. Higher SPQ subscale scores for Odd Behavior and Lack of Close Friends were significantly associated with the clinician-rated SIDP item scores in CTR but not SPD. CTR with low schizotypy scored lower on all SPQ subscales than CTR with high schizotypy, who did not differ from SPD. Self-report ratings are concordant with clinician ratings for positive schizotypal traits, whereas certain disorganization and interpersonal traits are not, particularly for individuals with SPD. The SPQ can differentiate between high and low schizotypy controls, but not between high schizotypy controls and individuals with SPD. Assessment of schizotypal traits should include both self-report questionnaires and clinician ratings.
Project description:While persuasive evidence has accumulated over the past 15 years documenting an association between schizophrenia and violence, there are 3 unresolved issues. First, does a downward extension of this relationship exist at the nonclinical level with respect to schizotypal personality and aggression in children? Second, is aggression more associated with impulsive reactive aggression or with more planned proactive aggression. Third and importantly, does peer victimization mediate the relationship between schizotypy and aggression? A further aim of this cross-sectional study was to examine the utility of a new child self-report measure of schizotypal personality. These issues were examined in a sample of 3804 schoolchildren assessed on schizotypy using the Schizotypal Personality Questionnaire-Child (SPQ-C), reactive-proactive aggression, and peer victimization. A confirmatory factor analysis confirmed the 3-factor structure (cognitive-perceptual, interpersonal, and disorganized) of the SPQ-C. Schizotypy was positively associated with total aggression and reactive aggression but not with proactive aggression. Peer victimization was found to significantly mediate the schizotypy-aggression relationship, accounting for 58.9% of the association. Results are broadly consistent with the hypothesis that schizotypal features elicit victimization from other children, which in turn predisposes to reactive retaliatory aggression. Findings are to the authors' knowledge the first to document any mediator of the schizotypy-aggression relationship and have potential treatment implications for violence reduction in schizophrenia-spectrum disorders. This study also provides initial evidence for the factorial and discriminant validity of a brief and simple measure of schizotypal personality in children as young as 8 years.
Project description:Schizotypy captures the underlying genetic vulnerability to schizophrenia. However, the genetic underpinnings of schizotypy remain unexplored. The authors examined the relationship between single nucleotide poly-morphisms (SNPs) and schizotypy. A sample of 137 subjects (43 healthy controls, 34 subjects with schizotypal personality disorder [SPD], 32 with borderline personality disorder, and 25 with other personality disorders) completed the Schizotypal Personality Questionnaire (SPQ). Subjects were genotyped using a custom array chip. Principal component analysis was used to cluster SPQ variables. Linear regression tested for associations between dimensional schizotypy and SNPs. Logistic regression tested for associations between SNPs and SPD diagnosis. There were significant associations between the minor alleles of three SNPs within the glycine receptor alpha 1 subunit (GLRA1) and the disorganized schizotypy dimension, even after Bonferroni correction. There were no significant associations between any SNPs and the categorical SPD diagnosis. Glycine receptor pathways may have an impact on dimensional traits of psychosis.
Project description:Elucidating schizotypal traits is important if we are to understand the various manifestations of psychosis spectrum liability and to reliably identify individuals at high risk for psychosis. The present study examined the network structures of (1) 9 schizotypal personality domains and (2) 74 individual schizotypal items, and (3) explored whether networks differed across gender and culture (North America vs China). The study was conducted in a sample of 27001 participants from 12 countries and 21 sites (M age = 22.12; SD = 6.28; 37.5% males). The Schizotypal Personality Questionnaire (SPQ) was used to assess 74 self-report items aggregated in 9 domains. We used network models to estimate conditional dependence relations among variables. In the domain-level network, schizotypal traits were strongly interconnected. Predictability (explained variance of each node) ranged from 31% (odd/magical beliefs) to 55% (constricted affect), with a mean of 43.7%. In the item-level network, variables showed relations both within and across domains, although within-domain associations were generally stronger. The average predictability of SPQ items was 27.8%. The network structures of men and women were similar (r = .74), node centrality was similar across networks (r = .90), as was connectivity (195.59 and 199.70, respectively). North American and Chinese participants networks showed lower similarity in terms of structure (r = 0.44), node centrality (r = 0.56), and connectivity (180.35 and 153.97, respectively). In sum, the present article points to the value of conceptualizing schizotypal personality as a complex system of interacting cognitive, emotional, and affective characteristics.