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.

Understanding others: a pilot investigation of cognitive and affective facets of social cognition in patients with 22q11.2 deletion syndrome (22q11DS)

BACKGROUND

Although significant impairments in the affective and cognitive facets of social cognition have been highlighted in patients with 22q11.2 deletion syndrome (22q11DS) in previous studies, these domains have never been investigated simultaneously within the same group of participants. Furthermore, despite theoretical evidence, associations between these two processes and schizotypal symptoms or social difficulties in this population have been scarcely examined.

METHODS

Twenty-nine participants with 22q11DS and 27 typically developing controls (N = 5 siblings; N = 22 unrelated controls) aged between 11 and 21 years participated in the study. Both groups were matched for age and gender distribution. Two computerized social cognition tasks evaluating perspective and emotion recognition abilities were administered to all participants. The levels of schizotypal trait expression and social functioning were further investigated in both groups, based on a validated self-report questionnaire (Schizotypal Personality Questionnaire) and parental interview (Vineland Adaptive Behavior Scales).

RESULTS

Participants with 22q11DS exhibited lower perspective-taking and emotion recognition capacities than typically developing controls. The two socio-cognitive dimensions investigated here were further correlated in healthy controls. The efficiency of perspective-taking processes (response time) was marginally related to the degree of schizotypal trait expression in patients with 22q11DS.

CONCLUSIONS

This study first provides support for significant deficits in two core facets of social cognition in 22q11DS. The associations observed between the experimental tasks and measures of social functioning or schizotypal symptoms in 22q11DS open promising research avenue, which should be more deeply investigated in future studies.

[Detection and early treatment of subjects at high risk of clinical psychosis: Definitions and recommendations]

In children and adolescents, psychotic disorders already represent one of the leading causes of disability-adjusted life years. During the past two decades, early detection of risk for psychosis has been intensively investigated, and in particular, predictive power for early signs of risk has been initiated and translated into clinical practice. In particular, the attenuated and transient positive symptoms of the ultra-high risk criteria, and the basic symptom criterion "cognitive disturbances", open promising routes to an indicated prevention and have recently been considered by the European Psychiatric Association (EPA) as diagnostic criteria of a psychosis-risk syndrome. The EPA recently provided evidence-based recommendations on the early detection of clinical high risk (CHR) for psychosis in patients with mental distress. In 2015, experts in the field of early detection conducted a meta-analysis reporting on studies examining conversion rates to psychosis in non-overlapping samples meeting at least one of the main CHR criteria: ultra-high risk (UHR) and/or basic symptoms criteria, examining the effects of potential moderators (different UHR criteria definitions, single UHR criteria and age) on conversion rates. In the 42 identified samples, comprising more than 4000 CHR patients who had been mainly identified by means of UHR criteria and/or the basic symptom criterion 'cognitive disturbances' (COGDIS), conversion rates showed considerable heterogeneity. While UHR and COGDIS criteria were related to comparable conversion rates until a 2-year follow-up, rates for COGDIS were significantly higher for follow-up periods beyond 2 years. Differences in onset and frequency requirements of symptomatic UHR criteria, or in their different consideration of functional decline, substance use and co-morbidity, did not seem to have an impact on conversion rates. The 'genetic risk and functional decline' UHR criterion was rarely met and only showed an insignificant pooled sample effect. However, age significantly affected UHR conversion rates with lower rates in children and adolescents. Although more research into potential sources of heterogeneity in conversion rates is needed to facilitate improvement of CHR criteria, six evidence-based recommendations for the early detection of psychosis were developed as a basis for the EPA guidance on early intervention in CHR states. The EPA guidance on early intervention aimed to provide evidence-based recommendations on early intervention in CHR states of psychosis, assessed according to the EPA guidance on early detection. The recommendations were also made by experts in the field of early intervention in psychoses and derived from a meta-analysis of current empirical evidence on the efficacy of psychological and pharmacological interventions in CHR samples. Eligible studies had to investigate conversion rate and/or functioning as a treatment outcome in CHR patients defined by the ultra-high risk and/or basic symptom criteria. In addition to analyses of treatment effects on conversion rate and functional outcome, age and type of intervention were examined as potential moderators. Based on data from 15 studies (n=1394), early intervention generally produced significantly reduced conversion rates at 6- to 48-month follow-up compared to control conditions. However, early intervention failed to achieve significantly greater functional improvements because both early intervention and control conditions produced similar positive effects. With regard to the type of intervention, both psychological and pharmacological interventions produced significant effects on conversion rates but not on functional outcome relative to the control conditions. Early intervention in youth samples was generally less effective than in predominantly adult samples. Seven evidence-based recommendations for early intervention in CHR samples have been formulated, although more studies are needed to investigate the specificity of treatment effects and potential age effects in order to tailor interventions to the individual treatment needs and risk status. Overall, age-related specificities and developmental transitions in the early detection and intervention in psychoses should be better accounted for in future research.

Schizotypal traits in adolescents with 22q11.2 deletion syndrome: validity, reliability and risk for psychosis

BACKGROUND

Very little is known about the phenotypic expression of schizotypal traits in individuals with 22q11.2 deletion syndrome (22q11DS). The main purpose was to analyse the factorial structure, internal consistency and temporal stability of schizotypal traits, as well as their associations with prodromal states and clinical psychotic symptoms in adolescents with 22q11DS.

METHOD

The sample comprised 61 adolescents with 22q11DS (mean = 14.95 years, s.d. = 2.13; n = 24 at follow-up). An age-matched comparison group (n = 61, mean = 15.44 years, s.d. = 1.76) was also included. The Schizotypal Personality Questionnaire (SPQ), the Structured Interview for Prodromal Syndromes, the Positive and Negative Syndrome Scale, and the Brief Psychiatric Rating Scale were used.

RESULTS

Adolescents with 22q11DS scored higher than the control group on the interpersonal dimension and suspiciousness subscale of the SPQ. The analysis of the internal structure of the SPQ in the sample of 22q11DS participants yielded a three-component solution (cognitive-perceptual, interpersonal, and disorganized). In addition, internal consistency coefficients ranged between 0.63 and 0.91. The schizotypal traits were highly stable across a 3.6-year interval, and ranged from 0.50 to 0.63. Self-reported schizotypal traits correlated with interview-based ratings of prodromal states and psychotic symptoms.

CONCLUSIONS

These results indicate that the SPQ may be a valid tool to assess schizotypal traits in adolescents with 22q11DS. The identification of a reliable self-report instrument for use in individuals with learning disabilities and at genetic high risk for psychosis could be useful in clinical and research settings. Assessment of schizotypal traits may be used as a distal risk marker and in a close-in strategy in high-risk genetic samples to enhance the possibility of early detection of psychosis.

[Validation study of the French schizotypal personality questionnaire in a sample of adolescents: a confirmatory factor analysis]

AIMS

This article aims to validate the schizotypal personality questionnaire in a sample of French speaking adolescents. Because early schizotypal manifestations are predictive of psychosis-proneness, reliable self-report measures are crucial for early detection of vulnerability to schizophrenia during adolescence. Unlike most existing self-reports, the questionnaire de personnalité schizotypique (SPQ) assesses individual differences in all nine feature of DSM-IV schizotypal personality (i.e. ideas of reference, excessive social anxiety, odd beliefs, unusual perceptual experience, odd behaviour, no close friends, odd speech, constricted affect and suspiciousness). Furthermore, it yields dimensional scores concerning the main schizotypal factors, which represent valuable information for the clinician's case formulation and can be used as a screening instrument in the general population.

METHOD

Our sample consisted of 174 adolescents (98 girls) between 12 and 17 years old. All completed the SPQ 74-item self-report. Participants were recruited in secondary schools in Switzerland, and through the child and adolescent community outpatient psychiatric service (office médico-pédagogique) affiliated to the University of Geneva's Psychiatry Department and to the Canton of Geneva Education Department. A confirmatory factorial analysis was conducted on our sample to test nine competing models of SPQ. The 3-factor model of Raine et al. was compared to concurrent 2, 3, and 4-factor models. Simple structure models of Raine et al. and Stefanis et al. were also tested.

RESULTS

The following observations were highlighted in our results: (1) goodness-of-fit indices are better for structures allowing cross loadings than for simple structures; (2) amongst the simple structures, the best goodness-of-fit index was obtained for the Raine model and (3) the fit between our data and the Raine model is improved by a cross loading for suspiciousness subscale. The latter seems problematic for the global data fitting. This led us to test simple structures models of Siever and Gunderson, Raine et al., and Stefanis et al., based on eight subscales rather than nine. Without suspiciousness subscale, goodness-of-fit indices are enhanced in these three models. The 3-factor model yields the clearest and most reliable results in comparison with other competing models. In summary, the best goodness-of-fit indices were obtained for the 3-factor Raine model. Goodness-of-fit indices could be improved by the exclusion of the suspiciousness scale.

CONCLUSIONS

Consistent with earlier analyses by Raine et al. and Dumas et al., our data confirm the 3-factor model of the SPQ (cognitive-perceptive; interpersonal; disorganized) in a sample of French speaking adolescents. Our analyses confirm that two dimensions are insufficient to explain the structure of schizotypy during adolescence. These results further suggest the stability of a 3-factor structure during lifespan. We note that the inclusion of the suspiciousness subscales engenders statistical issues. Most studies to date have dealt with these issues by performing a cross-loading with this subscale, or by the inclusion of a paranoid factor which is linked with the negative and the cognitive-perceptive factors. We found that the most statistically sound strategy was reached without the inclusion of the suspiciousness subscale. Future studies with larger samples could investigate the SPQ structure at an item-level, which carries the benefit of reduced restrictions on the factorial analysis. In conclusion, the current study shows that the French version SPQ constitutes a reliable self-report questionnaire for the assessment of schizotypal trait expression during adolescence that may assist in the evaluation of psychosis proneness in youths.

[Time processing in the velo-cardio-facial syndrome (22q11) and its link with the caudate nucleus]

INTRODUCTION

Velocardiofacial syndrome (VCFS) is a neurogenetic disorder caused by a microdeletion on chromosome 22q11. Among other cognitive impairments and learning difficulties, affected individuals show difficulties in estimating time intervals (Debbané et al., 2005). Interestingly, neuroimaging studies have found an increased volume of the basal ganglia of people with VCFS (Eliez et al., 2002; Kates et al., 2004; Campbell et al., 2006). Given that the caudate nucleus represents a central component of the cerebral network underlying temporal perception skills, the present report proposes to examine potential relationships between cerebral alteration to the caudate nucleus and time estimation in individuals with VCFS.

METHODS

A group of 30 patients with VCFS and 38 age-matched healthy individuals participated in time perception and time reproduction tasks. In the time perception task, individuals listened to two sequential stimuli and had to choose the longer of both stimuli by pressing a button. In the time reproduction task, subjects listened to a succession of sounds and once this succession had stopped they had to reproduce the same rhythm with their dominant index. Cerebral MRI images were also obtained for each participant. A manual tracing procedure was performed to measure the basal ganglia volume.

RESULTS

Participants with VCFS demonstrated significantly poorer performances during the time perception and time reproduction tasks in comparison to the control participants. Further, increased volume of the caudate nucleus was found in individuals with VCFS. Correlational analyses revealed a significant relationship between the caudate nucleus's volume and the performances obtained in the time perception task for control participants. This correlation was not found for individuals with VCFS.

CONCLUSION

The present results suggest that cerebral alterations to the caudate nucleus in VCFS may alter the temporal perception function it sustains.

Source monitoring for actions in adolescents with 22q11.2 deletion syndrome (22q11DS)

BACKGROUND

Source monitoring consists in identifying the origin of mental events. Recent research suggests that confusions over internally generated mental events may represent a cognitive marker for increased proneness to psychotic symptoms and disorders. We have examined source monitoring for actions in adolescents with the 22q11.2 deletion syndrome (22q11DS), a neurogenetic disease associated with high rates of schizophrenia during adulthood, and expected to observe source monitoring deficits in comparison to IQ-matched and typically developing controls.

METHOD

Eighteen adolescents with 22q11DS, 17 adolescents matched for age and IQ, and also 17 adolescents matched for age participated in this study. Our adapted action monitoring paradigm asked subjects to visualize a series of actions in three different conditions: (1) visualize themselves performing the action; (2) visualize the experimenter performing the action; or (3) simply repeat the action statements without visualization of the action performer.

RESULTS

The adolescents with 22q11DS performed adequately in terms of recognition (hits), but in comparison to both control groups, they committed more source confusions on correctly recognized items. Further examination revealed that the adolescents were more likely to demonstrate confusions between exterior sources in which the self was not involved.

CONCLUSIONS

Source monitoring deficits can be observed in adolescents with 22q11DS, a syndrome putting them at high risk for developing schizophrenia. These deficits are discussed in terms of early cognitive processes associated with genetic risk for schizophrenia.