The structure of schizotypal personality traits: a cross-national study.

BACKGROUND: Schizotypal traits are considered a phenotypic-indicator of schizotypy, a latent personality organization reflecting a putative liability for psychosis. To date, no previous study has examined the comparability of factorial structures across samples originating from different countries and cultures. The main goal was to evaluate the factorial structure and reliability of the Schizotypal Personality Questionnaire (SPQ) scores by amalgamating data from studies conducted in 12 countries and across 21 sites. METHOD: The overall sample consisted of 27 001 participants (37.5% males, n = 4251 drawn from the general population). The mean age was 22.12 years (s.d. = 6.28, range 16-55 years). The SPQ was used. Confirmatory factor analysis (CFA) and Multilevel CFA (ML-CFA) were used to evaluate the factor structure underlying the SPQ scores. RESULTS: At the SPQ item level, the nine factor and second-order factor models showed adequate goodness-of-fit. At the SPQ subscale level, three- and four-factor models displayed better goodness-of-fit indices than other CFA models. ML-CFA showed that the intraclass correlation coefficients values were lower than 0.106. The three-factor model showed adequate goodness of fit indices in multilevel analysis. The ordinal α coefficients were high, ranging from 0.73 to 0.94 across individual samples, and from 0.84 to 0.91 for the combined sample. CONCLUSIONS: The results are consistent with the conceptual notion that schizotypal personality is a multifaceted construct and support the validity and utility of SPQ in cross-cultural research. We discuss theoretical and clinical implications of our results for diagnostic systems, psychosis models and cross-national mental health strategies.

The role of stress-regulation genes in moderating the association of stress and daily-life psychotic experiences.

OBJECTIVE: The interaction of single nucleotide polymorphisms with both distal and proximal environmental factors across the extended psychosis phenotype is understudied. This study examined (i) the interaction of relevant SNPs with both early-life adversity and proximal (momentary) stress on psychotic experiences (PEs) in an extended psychosis sample; and (ii) differences between early-psychosis and non-clinical groups for these interactions. METHODS: Two hundred and forty-two non-clinical and 96 early-psychosis participants were prompted randomly eight times daily for 1 week to complete assessments of current experiences, including PEs and stress. Participants also reported on childhood trauma and were genotyped for 10 SNPs on COMT, RGS4, BDNF, FKBP5, and OXTR genes. RESULTS: Unlike genetic variants, distal and proximal stressors were associated with PEs in both samples and were more strongly associated with PEs in the early-psychosis than in the non-clinical group. The RGS4 TA and FKBP5 CATT haplotypes interacted with distal stress, whereas the A allele of OXTR (rs2254298) interacted with proximal stress, increasing momentary levels of PEs in the early-psychosis group. No interactions emerged with COMT or BDNF variants. CONCLUSION: Individual differences in relevant stress-regulation systems interact with both distal and proximal psychosocial stressors in shaping the daily-life manifestation of PEs across the psychosis continuum.

Predictors of expressed emotion, burden and quality of life in relatives of Mexican patients with psychosis.

Expressed emotion, burden and quality of life of relatives received attention because of the increasing interest in predicting and preventing relapse in psychotic patients; but they have subsequently acquired interest of their own as important aspects of families' psychological well-being. The study explores whether the psychological distress and illness perception of a sample of relatives of Mexican patients with psychosis can predict their levels of expressed emotion, burden and quality of life above patients' clinical and functional status. Sixty-five patient-relative dyads were interviewed. Relatives self-reported on expressed emotion, burden, quality of life, psychological distress and illness perception. Patients' clinical and functional status was rated by an interviewer. Pearson correlations and hierarchical multiple linear regressions were used for statistical analyses. Patients' functional status and relatives' psychological distress were significantly associated with expressed emotion, burden and quality of life. Patients' clinical status and relatives' illness perception were most strongly related to expressed emotion and burden. Relatives' psychological distress and illness perception dimensions predicted both burden and quality of life, over and above patients' clinical and functional status. Results underscore the relatives' need of support to overcome their own distress and concerns about the illness, for the psychological well-being of both patients and relatives.

The expression of positive and negative schizotypy in daily life: an experience sampling study.

BACKGROUND: Psychometrically identified positive schizotypy and negative schizotypy are differentially related to psychopathology, personality and social functioning. However, little is known about the experience and expression of schizotypy in daily life and the psychological mechanisms that trigger psychotic-like experiences. METHOD: The present study employed experience sampling methodology (ESM) to assess positive and negative schizotypy in daily life in a non-clinical sample of 412 young adults. ESM is a structured diary technique in which participants are prompted at random times during the day to complete assessments of their current experiences. RESULTS: As hypothesized, positive schizotypy was associated with increased negative affect, thought impairment, suspiciousness, negative beliefs about current activities and feelings of rejection, but not with social disinterest or decreased positive affect. Negative schizotypy, on the other hand, was associated with decreased positive affect and pleasure in daily life, increased negative affect, and decreases in social contact and interest. Both positive schizotypy and negative schizotypy were associated with the desire to be alone when with others. However, this was moderated by anxiety in positive schizotypy and by diminished positive affect in negative schizotypy. CONCLUSIONS: The results support the construct validity of a multidimensional model of schizotypy and the ecological validity of the positive and negative schizotypy dimensions. ESM appears to be a promising method for examining the daily life experiences of schizotypic individuals.

Social skills and associated psychopathology in children with chromosome 22q11.2 deletion syndrome: implications for interventions.

BACKGROUND: Although distinctive neuropsychological impairments have been delineated in children with chromosome 22q11 deletion syndrome (22q11DS), social skills and social cognition remain less well-characterised. OBJECTIVE: To examine social skills and social cognition and their relationship with neuropsychological function/behaviour and psychiatric diagnoses in children with 22q11DS. METHODS: Sixty-six children with 22q11DS and 54 control participants underwent neuropsychological testing and were administered the Diagnostic Analysis of Non-Verbal Accuracy (DANVA) for face and auditory emotion recognition, a measure of social cognition: their parents/guardians were administered the Social Skills Rating System (SSRS) - parent version, Child Behavior Checklist (CBCL) - parent version and the Computerised Diagnostic Interview Schedule for Children (C-DISC). RESULTS: The 22q11DS group exhibited significantly lower social skills total score and more problem social behaviours, lower neurocognitive functioning, higher rates of anxiety disorders and more internalising symptoms than the control group. Participants with 22q11DS also exhibited significant deficits in their ability to read facial expressions compared with the control group, but performed no differently than the control participants in the processing of emotions by tone of voice. Within the 22q11DS group, higher social competency was correlated with higher global assessment of functioning and parental socio-economic status. Social competency was worse in those with anxiety disorders, attention deficit hyperactivity disorder, more than two psychiatric diagnoses on the C-DISC and higher internalising symptoms. No significant correlations of SSRS scores were seen with IQ, executive functions, attention, or verbal learning and memory. No correlations were found between social cognition and social skill scores. CONCLUSION: Our results indicate that social skills in children with 22q11DS are associated with behaviour/emotional functioning and not with neurocognition. Thus, treating the behaviour or emotional problems such as attention deficit hyperactivity disorder and anxiety disorders may provide a pathway for improving social skills in these children.

Adaptation of the wisconsin scales of psychosis proneness to Spanish.

INTRODUCTION: Nowadays the study of vulnerability to psychosis and early intervention is an area of great clinical impact and research. The aim of this study was to adapt the Wisconsin Scales of Vulnerability to Psychosis from English to Spanish. A set of five scales (Magical Ideation, Perceptual Aberration, Physical Anhedonia, Revised Social Anhedonia and Ambivalence) assess schizotypal traits in the general population and the possible risk of developing disorders embedded in the psychotic spectrum. Additionally, this tool contains a scale of Hypomaniac Personality to detect risk of affective spectrum psychosis. METHODOLOGY: The Wisconsin Scales of Vulnerability to Psychosis have been adapted following the back-translation method. The scales were translated to an original Spanish version, which was then translated again into English in order to assess the conceptual and semantic overlap with the original items. RESULTS: All the items were back-translated and evaluated in respect to the original ones by an expert in the scales, and all of them were rated with a perfect equivalence (Type A) or satisfactory (Type B). CONCLUSIONS: The Spanish version of the Wisconsin Scales of Vulnerability to Psychosis shows good equivalence with the English one, thus allowing to measure affective and schizotypal traits in samples of Spanish-speaking individuals properly. Future studies should test the reliability and validity of these scales in our environment.

Cognitive correlates of a functional COMT polymorphism in children with 22q11.2 deletion syndrome.

Chromosome 22q11.2 deletion syndrome (22q11DS) is a common microdeletion syndrome associated with a markedly elevated risk of schizophrenia in adulthood. Cognitive impairments such as a low IQ and deficits in attention and executive function are common in childhood. The catechol O-methyltransferase (COMT) gene maps within the deleted region and is involved in the degradation of dopamine, a neurotransmitter thought to be important in cognition and the development of schizophrenia. Thus, we examined the correlation between neurocognitive deficits and a common polymorphism Val(158)Met in the COMT gene in a cohort of children with 22q11DS. Our results show that children with 22q11DS who have the Met allele have higher IQ and achievement scores and perform better on measures of prefrontal cognition, such as the Continuous Performance Task, as compared with those with the Val allele. These results confirm that the hemizygous COMT Val(158)Met genotype impacts upon cognition in children with 22q11DS.

Dissociative experience in hypothetically psychosis-prone college students.

The relationship between dissociative experiences and psychosis proneness was investigated in a sample of 523 college undergraduates. Participants were administered the Dissociative Experiences Scale (DES), the Perceptual Aberration Scale, the Magical Ideation Scale, the Social Anhedonia Scale, and the Physical Anhedonia Scale. As hypothesized, the Perceptual Aberration and Magical Ideation Scales were positively correlated with the DES. The Social Anhedonia Scale had a modest correlation with the DES, but this relationship was largely mediated by the Perceptual Aberration and Magical Ideation Scales. The Physical Anhedonia Scale was uncorrelated with the DES. Exploratory factor analysis of the psychosis-proneness scales and the DES subscales resulted in a three-factor solution: dissociative experiences, positive schizotypy, and negative schizotypy. The DES depersonalization subscale loaded on both the dissociation and positive schizotypy factors.

A ten-year longitudinal study of intense ambivalence as a predictor of risk for psychopathology.

The predictive validity of the Intense Ambivalence Scale was examined in a 10-year longitudinal study of 362 psychometrically identified psychosis-prone and control participants. Elevated scores on the Intense Ambivalence Scale predicted psychotic-like and depressive symptoms, and the development of psychotic illnesses at the 10-year follow-up assessment (after the removal of variance for membership in the psychosis-prone and control groups). Elevated scores on the scale were also associated with substance abuse, schizotypal symptoms, and impaired functioning at both the initial and follow-up assessments. The Intense Ambivalence Scale did not differentially enhance the predictive power of the Perceptual Aberration or the Magical Ideation Scales.

A longitudinal study of high scorers on the hypomanic personality scale.

Former college students (n = 36) identified by high scores on the Hypomanic Personality Scale (HYP; Eckblad & Chapman, 1986) were compared with control participants (n = 31) at a 13-year follow-up assessment. As hypothesized, the HYP group reported more bipolar disorders and major depressive episodes than the control group. The HYP group also exceeded the control group on the severity of psychotic-like experiences, symptoms of borderline personality disorder, and rates of substance use disorders. HYP group members with elevated scores on the Impulsive-Nonconformity Scale (Chapman et al., 1984) experienced greater rates of bipolar mood disorders, poorer overall adjustment, and higher rates of arrest than the remaining HYP or control participants.

Smooth pursuit eye tracking and visual fixation in psychosis-prone individuals.

Subjects identified by Perceptual Aberration-Magical Ideation (Per-Mag) scores (n=97), Social Anhedonia (SocAnh) scores (n=45), and Physical Anhedonia (PhysAnh) scores (n=31) as well as normal controls (n=94), underwent psychophysiological and clinical assessment. This is the first published investigation of pursuit system functioning in three groups of questionnaire-identified at-risk individuals. Pursuit during a simple non-monitor tracking task was measured using root-mean-square error (RMSE) scores and pursuit gain scores. Fixation performance was measured in terms of number of saccades away from the central fixation point. The at-risk subjects were more likely to display aberrant smooth pursuit tracking than controls, though there were no significant differences between the at-risk subjects endorsing items relevant to positive-symptom schizotypy and those endorsing items pertaining to negative-symptom schizotypy. The groups did not differ significantly in their visual fixation performance. Participants were also evaluated for the presence of Axis I symptomatology and psychotic-like experiences. Neither the experimental subjects nor the control subjects displayed a significant association between ocular motor performance and psychotic-like experiences. These findings are consistent with prior evidence that pursuit tracking is a trait characteristic, independent of clinical status.

Validity and usefulness of the Wisconsin Manual for Assessing Psychotic-like Experiences.

The Wisconsin Manual for Assessing Psychotic-like Experiences is an interview-based assessment system for rating psychotic and psychotic-like symptoms on a continuum of deviancy from normal to grossly psychotic. The original manual contained six scales, assessing thought transmission, passivity experiences, thought withdrawal, auditory experiences, personally relevant aberrant beliefs, and visual experiences. A seventh scale assessing deviant olfactory experiences was subsequently added. The rating scales have good interrater reliability when used by trained raters. Cross-sectional studies indicated that the frequency and deviancy of psychotic-like experiences are elevated among college students who were identified, hypothetically, as psychosis prone by other criteria. Psychotic-like experiences of moderate deviancy in college students successfully predicted the development of psychotic illness and poorer overall adjustment 10 years later. The manual is useful for identifying psychosis-prone individuals and is recommended for use in linkage and treatment outcome studies. The present article provides an interview schedule for collecting information required for rating psychotic-like experiences.

Wisconsin Card Sorting Test deficits in schizotypic individuals.

The present study investigates executive functioning in schizotypic college students and control subjects using the Wisconsin Card Sorting Test (WCST). Inhibitory control and working memory, two aspects of executive functioning, were examined in deviantly high scorers on the Perceptual Aberration and Magical Ideation Scales (n=97), high scorers on the revised Social Anhedonia Scale (n=58), and in control subjects (n=104). The schizotypic groups displayed significantly more perseverative errors and achieved fewer categories than the control group. The two schizotypic groups did not differ from each other. We identified a subset of schizotypic individuals who also produced clinically deviant WCST profiles. The findings support the hypothesis that executive function deficits may precede the onset of schizophrenia and related illnesses.

Social anhedonia as a predictor of the development of schizophrenia-spectrum disorders.

College undergraduates (n = 34) identified by deviant scores (at least 1.96 SD above the mean) on the Revised Social Anhedonia (SocAnh) Scale (M. Eckblad, L. J. Chapman, J. P. Chapman, & M. Mishlove, 1982) were compared with control participants (n = 139) at an initial assessment and at a 10-year follow-up evaluation. Twenty-four percent of the SocAnh group were diagnosed with schizophrenia-spectrum disorders at the follow-up compared with only 1% of the control group, despite the fact that there had been no such difference between the groups at the initial assessment 10 years earlier. The SocAnh group exceeded the control group on severity of psychotic-like experiences and had poorer overall adjustment at the follow-up but not at the initial assessment. The groups did not differ on mood symptoms or substance-use disorders. Thus, the SocAnh Scale, unlike the Perceptual Aberration and Magical Ideation Scales, appears to identify individuals at specific risk for future development of schizophrenia-spectrum disorders.

Magical ideation and social anhedonia as predictors of psychosis proneness: a partial replication.

The authors compared college students identified by high scores on the Magical Ideation Scale (M. Eckblad & L. J. Chapman, 1983) and the Revised Social Anhedonia Scale (MagSoc; n = 28; M. Eckblad, L. J. Chapman, J. P. Chapman, & M. Mishlove, 1982) with control participants (n = 20) at a 10-year follow-up assessment in an attempt to replicate L. J. Chapman, J. P. Chapman, T. R. Kwapil, M. Eckblad, and M. C. Zinser's (1994) report of heightened psychosis proneness in MagSoc individuals. The MagSoc group exceeded the control group on severity of psychotic-like experiences; ratings of schizotypal, paranoid, and borderline personality disorder symptoms; and rates of mood and substance use disorders. Two of the MagSoc participants but none of the control participants developed psychosis during the follow-up period (a nonsignificant difference). Consistent with L. J. Chapman et al.'s findings, the groups did not differ on rates of personality disorders or relatives with psychosis.

A longitudinal study of drug and alcohol use by psychosis-prone and impulsive-nonconforming individuals.

The rates of substance use and abuse are higher among psychotic patients and antisocial individuals than in the general population. In a 10-year longitudinal study, psychosis-prone individuals identified by the Perceptual Aberration (L. J. Chapman, J. P. Chapman, M. L. Raulin, 1976) and Magical Ideation (Per-Mag) scales (M. Eckblad & L. J. Chapman, 1983), and individuals with antisocial traits, identified by the Impulsive Nonconformity (Noncon) scale (L. J. Chapman et al., 1984), exceeded a control group on rates of substance use disorders. As hypothesized, the Per-Mag group demonstrated preferential patterns of substance use similar to those reported for schizophrenic patients. Participants who scored deviantly on both the Per-Mag and Noncon scales were at especially heightened risk for substance use disorders. Psychosis proneness at the initial screening predicted substance abuse at the follow-up evaluation, but substance abuse at the initial interview did not predict later clinical psychosis or psychoticlike experiences.

Deviant olfactory experiences as indicators of risk for psychosis.

Olfactory hallucinations, although relatively rare, are reportedly indicative of serious psychopathology and poor prognosis in psychotic patients. This article describes the development of a rating scale for assessing olfactory experiences of psychotic and psychoticlike deviancy. The scale is modeled after Chapman and Chapman's rating scales for other psychoticlike experiences, which have been found to predict psychosis and psychosis-proneness. In a longitudinal study, college students who reported deviant olfactory experiences at their initial assessment (n = 31) exceeded the remaining subjects (n = 477) on DSM-III-R psychosis and on measures of psychosis proneness at a 10-year followup. Furthermore, hypothetically psychosis-prone subjects identified by the Perceptual Aberration and Magical Ideation scales exceeded control subjects on ratings of olfactory experiences at both initial and followup assessments.

Putatively psychosis-prone subjects 10 years later.

The predictive validities of several indicators of psychosis proneness were evaluated in a 10-year longitudinal study (N = 508). As hypothesized, high scorers on the Perceptual Aberration Scale, Magical Ideation Scale, or both (n = 182), especially those who initially reported psychoticlike experiences of at least moderate deviance, exceeded control subjects (n = 153) on psychoses (revised 3rd edition of the Diagnostic and Statistical Manual of Mental Disorders), psychotic relatives, schizotypal symptoms, and psychoticlike experiences at follow up. Ss who initially scored high on the Magical Ideation Scale and above the mean on the Social Anhedonia Scale were especially deviant. The Physical Anhedonia Scale and the Impulsive Nonconformity Scale were not effective predictors of psychosis proneness.

Slowness and the preceding preparatory interval effect in schizophrenia.

We measured the reaction times (RTs) of schizophrenic (n = 25), matched normal (n = 69), and bipolar (n = 14) subjects to a tone preceded by a preparatory interval (PI; the time between the warning signal and imperative stimulus) of varying length. RTs increase when the PI for the immediately preceding trial (the PPI) is longer than the PI for the current trial. Several studies have shown that this PPI effect (difference score) is heightened in schizophrenia. We replicated this finding. However, we found that the size of the PPI effect within groups increased with overall slowness and that the least squares regression line relating the PPI effect difference score to overall slowness did not differ between groups, nor did schizophrenic subjects' regression line differ from that of normal subjects. Group differences on the PPI effect were also analyzed by taking residuals for members of all groups from the normal subjects' regression line of the PPI effect difference score on overall slowness. Groups did not differ on these residuals, nor did schizophrenic subjects differ from normal subjects. We conclude that the heightening of the PPI effect in schizophrenia is like that observed in equally slow normal subjects. This finding suggests that the PPI effect does not appear to be a promising marker of a distinctive schizophrenic pathology.

Monaural and binaural story recall by schizophrenic subjects.

P. Green and other investigators have reported that schizophrenic Ss have poorer recall of stories presented to both ears than to the single best ear (binaural deficit) and poorer recall of stories presented to the left ear than to the right ear (monaural asymmetry) than do normal control Ss. These studies are plagued by potential methodological problems, including differences in overall accuracy, which artifactually affect the difference scores, and scoring methods that are vulnerable to systematic bias. In this study, scores of schizophrenic, bipolar, and normal control Ss on the Auditory Comprehension Test were compared. Scoring bias was avoided by the use of blind scoring and a revised scoring manual, and artifactual effects of accuracy were considered in interpreting the results. Contrary to previous findings, the groups did not differ on either monaural asymmetry or binaural deficit.