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.

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.

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.

Early adversity and 5-HTT/BDNF genes: new evidence of gene-environment interactions on depressive symptoms in a general population.

BACKGROUND: Adverse childhood experiences have been described as one of the major environmental risk factors for depressive disorder. Similarly, the deleterious impact of early traumatic experiences on depression seems to be moderated by individual genetic variability. Serotonin transporter (5-HTT) and brain-derived neurotrophic factor (BDNF) modulate the effect of childhood adversity on adult depression, although inconsistencies across studies have been found. Moreover, the gene x environment (GxE) interaction concerning the different types of childhood adversity remains poorly understood. The aim of this study was to analyse the putative interaction between the 5-HTT gene (5-HTTLPR polymorphism), the BDNF gene (Val66Met polymorphism) and childhood adversity in accounting for adult depressive symptoms. METHOD: A sample of 534 healthy individuals filled in self-report questionnaires of depressive symptomatology [the Symptom Check List 90 Revised (SCL-90-R)] and different types of childhood adversities [the Childhood Trauma Questionnaire (CTQ)]. The 5-HTTLPR polymorphism (5-HTT gene) and the Val66Met polymorphism (BDNF gene) were genotyped in the whole sample. RESULTS: Total childhood adversity (beta=0.27, p<0.001), childhood sexual abuse (CSA; beta=0.17, p<0.001), childhood emotional abuse (beta=0.27, p<0.001) and childhood emotional neglect (beta=0.22, p<0.001) had an impact on adult depressive symptoms. CSA had a greater impact on depressive symptoms in Met allele carriers of the BDNF gene than in the Val/Val group (F=5.87, p<0.0001), and in S carriers of the 5-HTTLPR polymorphism (5-HTT gene) (F=5.80, p<0.0001). CONCLUSIONS: Childhood adversity per se predicted higher levels of adult depressive symptoms. In addition, BDNF Val66Met and 5-HTTLPR polymorphisms seemed to moderate the effect of CSA on adult depressive symptoms.

Putative role of the COMT gene polymorphism (Val158Met) on verbal working memory functioning in a healthy population.

Working memory has been described as a neurocognitive probe of prefrontal brain functioning. Genetic variability related with catechol-O-methyltransferase (COMT) gene (Val158Met polymorphism) has received increasing attention as a possible modulator of working memory tasks in both schizophrenic patients and healthy subjects, although inconsistencies across studies have been found. This may be related to the existence of different working memory components, processes and modalities, which may have different sensitivities to subtle changes in dopamine levels and, therefore, the effect of the underlying COMT Val158Met genetic variability. To test this out a large sample of 521 healthy individuals from the general population were tested on the WCST and three working memory tasks that cover the assessment of verbal and spatial working modalities as well as different components and processes (Letter and Number Sequencing, CPT-IP, Backwards Visual Span). All individuals were genotyped for the rs4680 (Val158Met) polymorphism at the COMT gene. Met carriers showed near-significant better performance in the LNS compared with Val/Val individuals (F = 3.9, df = 1, P = 0.046). Moreover, the analysis for linear trend found that Met allele carriers showed significantly better performance than Val/Val individuals (B = 0.58 P = 0.031), although evidence for a linear trend was not found. None of the WCST indices differed among genotypes. Consistent with the hypothesis that Val158Met polymorphism (COMT gene) might account for individual differences on dopamine-dependent prefrontally related neurocognitive functions, the Letter-Number Sequencing task, which requires not only maintenance but also active manipulation of information seemed to be more sensitive to the disadvantageous Val/Val genotype in a large non-clinical sample.

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.

Process of adaptation to Spanish of the Temperament Evaluation of Memphis, Pisa, Paris and San Diego Scale. Self applied version (TEMPS-A).

INTRODUCTION: Investigation of the predisposing factors for affective disorders has shown that measures to assess affective temperament are necessary. The TEMPS-A is a self-evaluation measure to assess four affective temperaments (hyperthymic, depressive, cyclothymic and irritable) and anxious temperament. METHOD: The TEMPS-A questionnaire version that includes 110 questions has been adapted following the translation-backtranslation methodology, including two translations to Spanish and the classification of equivalence to English by an independent author. RESULTS: The study results indicated that a satisfactory translation was obtained, as indicated by the validation of equivalence by the bilingual consultant. All the items showed a perfect (A) or satisfactory equivalence (B). CONCLUSIONS: The TEMPS-A, Spanish version, is an understandable questionnaire that is equivalent to the original version in English, that allows for the evaluation of affective temperaments.