A reassessment of the higher-order factor structure of the German Schizotypal Personality Questionnaire (SPQ-G) in German-speaking adults.

The Schizotypal Personality Questionnaire (SPQ) is a widely-used self-report instrument for the assessment of schizotypal personality traits. However, the factor structure of scores on English and non-English translations of the SPQ has been a matter of debate. With little previous factorial evaluation of the German version of the SPQ (SPQ-G), we re-assessed the higher-order factor structure of the measure. A total of 2,428 German-speaking adults from Central Europe (CE) and the United Kingdom (UK) completed the SPQ-G. Confirmatory factor analysis - testing proposed 2-, 3-, and 4-factor models of SPQ-G scores - indicated that the 4-factor solution had best fit. Partial measurement invariance across cultural group (CE and UK) and sex was obtained for the 4-factor model. Further analyses showed CE participants had significantly higher scores than UK participants on one schizotypal facet. These results suggest that scores on the SPQ-G are best explained in terms of a higher-order, 4-factor solution in German migrant and non-migrant adults.

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.

Psychometric properties of the Malay Schizotypal Personality Questionnaire: Measurement invariance and latent mean comparisons in Malaysian adults.

INTRODUCTION: The Schizotypal Personality Questionnaire (SPQ) is a widely used self-report measurement instrument for the assessment of schizotypal personality traits. However, the factor structure of the SPQ has been a matter of some debate. As a contribution to this debate, we examined the factor structure of the SPQ in Malaysian adults. METHOD: A total of 382 Malaysian adults completed a Malay translation of the SPQ. Confirmatory factory analysis was used to examine the fit of 3- and 4-factor solutions for the higher-order dimensionality of the SPQ. Ethnic invariance for the best-fitting model was tested at the configural, metric, and scalar levels, and a multivariate analysis of variance was used to examine sex and ethnicity differences in domain scores. RESULTS: The 4-factor model provided a better fit to the data than did the 3-factor model. The 4-factor model also demonstrated partial measurement invariance across ethnic groups. Latent mean comparisons for sex and ethnicity revealed a number of significant differences for both factors, but effect sizes were small. DISCUSSION: The 4-factor structure of the SPQ received confirmatory support and can be used in Malay-speaking populations.

Clinical utility of magnetic resonance imaging in first-episode psychosis.

BackgroundThere is no consensus as to whether magnetic resonance imaging (MRI) should be used as part of the initial clinical evaluation of patients with first-episode psychosis (FEP).Aims(a) To assess the logistical feasibility of routine MRI; (b) to define the clinical significance of radiological abnormalities in patients with FEP.MethodRadiological reports from MRI scans of two FEP samples were reviewed; one comprised 108 patients and 98 healthy controls recruited to a research study and the other comprised 241 patients scanned at initial clinical presentation plus 66 healthy controls.ResultsIn the great majority of patients, MRI was logistically feasible. Radiological abnormalities were reported in 6% of the research sample and in 15% of the clinical sample (odds ratio (OR)=3.1, 95% CI 1.26-7.57, χ2(1) = 6.63, P = 0.01). None of the findings necessitated a change in clinical management.ConclusionsRates of neuroradiological abnormalities in FEP are likely to be underestimated in research samples that often exclude patients with organic abnormalities. However, the majority of findings do not require intervention.

Examination of the factor structure of the Schizotypal Personality Questionnaire among British and Trinidadian adults.

Much debate in schizotypal research has centred on the factor structure of the Schizotypal Personality Questionnaire (SPQ), with research variously showing higher-order dimensionality consisting of two to seven dimensions. In addition, cross-cultural support for the stability of those factors remains limited. Here, we examined the factor structure of the SPQ among British and Trinidadian adults. Participants from a White British subsample (n = 351) resident in the UK and from an African Caribbean subsample (n = 284) resident in Trinidad completed the SPQ. The higher-order factor structure of the SPQ was analysed through confirmatory factor analysis, followed by multiple-group analysis for the model of best fit. Between-group differences for sex and ethnicity were investigated using multivariate analysis of variance in relation to the higher-order domains. The model of best-fit was the four-factor structure, which demonstrated measurement invariance across groups. Additionally, these data had an adequate fit for two alternative models: (a) 3-factor and (b) modified 4-factor model. The British subsample had significantly higher scores across all domains than the Trinidadian group, and men scored significantly higher on the disorganised domain than women. The four-factor structure received confirmatory support and, importantly, support for use with populations varying in ethnicity and culture.

Differential relationship between neurological and cognitive dysfunction in first episode psychosis patients and in healthy individuals.

The minor neurological and cognitive deficits consistently reported in psychoses may reflect the same underlying brain dysfunction. Still, even in healthy individuals minor neurological abnormalities are associated with worse cognitive function. Therefore, establishing which neurological and cognitive deficits are specific to psychosis is essential to inform the pathophysiology of this disorder. We evaluated a large epidemiological sample of patients with first episode psychosis (n=242) and a population-based sample of healthy individuals (n=155), as part of the AESOP study. We examined neurological soft signs using the Neurological Evaluation Scale (Buchanan and Heinrichs, 1989), and generalized and specific cognitive deficits (memory; verbal abilities; attention, concentration and mental speed; executive functions and working memory; language; visual constructual/perceptual abilities). In patients, more neurological signs across all subscales were associated with worse general cognitive function, while in controls this was only present for sensory integration and sequencing signs. Furthermore, in patients, but not in healthy individuals, more sensory integrative signs were associated with deficits in specific cognitive domains, such as memory, verbal abilities, language, visual/perceptual, executive function (p ranging <0.001-0.002); sequencing signs with language, executive function, and attention (p<0.001-0.004); and motor signs with poorer verbal abilities (p=0.001). These findings indicate the presence of specific associations between neurological and cognitive deficits in psychosis that are distinct from those of healthy individuals.

Insight, grey matter and cognitive function in first-onset psychosis.

BACKGROUND: Several studies have suggested that neuropsychological and structural brain deficits are implicated in poor insight. Few insight studies however have combined neurocognitive and structural neuroanatomical measures. AIMS: Focusing on the ability to relabel psychotic symptoms as pathological, we examined insight, brain structure and neurocognition in first-onset psychosis. METHOD: Voxel-based magnetic resonance imaging data were acquired from 82 individuals with psychosis and 91 controls assessed with a brief neuropsychological test battery. Insight was measured using the Schedule for the Assessment of Insight. RESULTS: The principal analysis showed reduced general neuropsychological function was linked to poor symptom relabelling ability. A subsequent between-psychosis group analysis found those with no symptom relabelling ability had significant global and regional grey matter deficits primarily located at the posterior cingulate gyrus and right precuneus/cuneus. CONCLUSIONS: The cingulate gyrus (as part of a midline cortical system) along with right hemisphere regions may be involved in illness and symptom self-appraisal in first-onset psychosis.

Insight, grey matter and cognitive function in first-onset psychosis

BACKGROUND: Several studies have suggested that neuropsychological and structural brain deficits are implicated in poor insight. Few insight studies however have combined neurocognitive and structural neuroanatomical measures. AIMS: Focusing on the ability to relabel psychotic symptoms as pathological, we examined insight, brain structure and neurocognition in first-onset psychosis.METHOD: Voxel-based magnetic resonance imaging data were acquired from 82 individuals with psychosis and 91 controls assessed with a brief neuropsychological test battery. Insight was measured using the Schedule for the Assessment of Insight. RESULTS: The principal analysis showed reduced general neuropsychological function was linked to poor symptom relabelling ability. A subsequent between-psychosis group analysis found those with no symptom relabelling ability had significant global and regional grey matter deficits primarily located at the posterior cingulate gyrus and right precuneus/cuneus. CONCLUSIONS: The cingulate gyrus (as part of a midline cortical system) along with right hemisphere regions may be involved in illness and symptom self-appraisal in first-onset psychosis.

Insight, grey matter and cognitive function in first-onset psychosis.

BACKGROUND: Several studies have suggested that neuropsychological and structural brain deficits are implicated in poor insight. Few insight studies however have combined neurocognitive and structural neuroanatomical measures.AIMS: Focusing on the ability to relabel psychotic symptoms as pathological, we examined insight, brain structure and neurocognition in first-onset psychosis.METHOD: Voxel-based magnetic resonance imaging data were acquired from 82 individuals with psychosis and 91 controls assessed with a brief neuropsychological test battery. Insight was measured using the Schedule for the Assessment of Insight.RESULTS: The principal analysis showed reduced general neuropsychological function was linked to poor symptom relabelling ability. A subsequent between-psychosis group analysis found those with no symptom relabelling ability had significant global and regional grey matter deficits primarily located at the posterior cingulate gyrus and right precuneus/cuneus.CONCLUSIONS: The cingulate gyrus (as part of a midline cortical system) along with right hemisphere regions may be involved in illness and symptom self-appraisal in first-onset psychosis.

Neurological abnormalities and cognitive ability in first-episode psychosis.

BACKGROUND: It remains unclear if the excess of neurological soft signs, or of certain types of neurological soft signs, is common to all psychoses, and whether this excess is simply an epiphenomenon of the lower general cognitive ability present in psychosis. AIMS: To investigate whether an excess of neurological soft signs is independent of diagnosis (schizophrenia v. affective psychosis) and cognitive ability (IQ). METHOD: Evaluation of types of neurological soft signs in a prospective cohort of all individuals presenting with psychoses over 2 years (n=310), and in a control group from the general population (n=239). RESULTS: Primary (P<0.001), motor coordination (P<0.001), and motor sequencing (P<0.001) sign scores were significantly higher in people with any psychosis than in the control group. However, only primary and motor coordination scores remained higher when individuals with psychosis and controls were matched for premorbid and current IQ. CONCLUSIONS: Higher rates of primary and motor coordination signs are not associated with lower cognitive ability, and are specific to the presence of psychosis.

Neurological abnormalities and cognitive ability in first-episode psychosis.

BACKGROUND: It remains unclear if the excess of neurological soft signs, or of certain types of neurological soft signs, is common to all psychoses, and whether this excess is simply an epiphenomenon of the lower general cognitive ability present in psychosis. AIMS: To investigate whether an excess of neurological soft signs is independent of diagnosis (schizophrenia v. affective psychosis) and cognitive ability (IQ). METHOD: Evaluation of types of neurological soft signs in a prospective cohort of all individuals presenting with psychoses over 2 years (n=310), and in a control group from the general population (n=239). RESULTS: Primary (P<0.001), motor coordination (P<0.001), and motor sequencing (P<0.001) sign scores were significantly higher in people with any psychosis than in the control group. However, only primary and motor coordination scores remained higher when individuals with psychosis and controls were matched for premorbid and current IQ. CONCLUSIONS: Higher rates of primary and motor coordination signs are not associated with lower cognitive ability, and are specific to the presence of psychosis.

Sexually dimorphic changes in the amygdala in relation to delusional beliefs in first episode psychosis.

BACKGROUND: Few attempts have been made to examine the relationship between amygdala abnormalities and specific symptoms in psychosis. The present study explored the relationship between amygdala morphology and mood congruent and mood incongruent delusional beliefs. METHODS: Amygdala volumes were measured in 43 patients presenting with delusional beliefs in the context of their first episode of psychosis and 43 healthy volunteers matched for age and gender. RESULTS: Left-greater-than-right-asymmetry of the amygdala varied as a function of gender and mood congruence of delusional beliefs, due to asymmetrical enlargement of the left amygdala in women presenting with predominantly mood incongruent delusions. However, there was no difference in amygdala volumes across groups. CONCLUSIONS: Amygdala abnormalities in women may be associated with aberrant emotional processing that could contribute to the development of mood incongruent delusional beliefs. Sexually dimorphic changes in the amygdala may contribute to differential phenotypic illness expression in men and women.

Grey matter abnormalities in first-episode schizophrenia and affective psychosis.

BACKGROUND: Grey matter and other structural brain abnormalities are consistently reported in first-onset schizophrenia, but less is known about the extent of neuroanatomical changes in first-onset affective psychosis. AIMS: To determine which brain abnormalities are specific to (a) schizophrenia and (b) affective psychosis. METHOD: We obtained dual-echo (proton density/T2-weighted) magnetic resonance images and carried out voxel-based analysis on the images of 73 patients with first-episode psychosis (schizophrenia n=44, affective psychosis n=29) and 58 healthy controls. RESULTS: Both patients with schizophrenia and patients with affective psychosis had enlarged lateral and third ventricle volumes. Regional cortical grey matter reductions (including bilateral anterior cingulate gyrus, left insula and left fusiform gyrus) were evident in affective psychosis but not in schizophrenia, although patients with schizophrenia displayed decreased hippocampal grey matter and increased striatal grey matter at a more liberal statistical threshold. CONCLUSIONS: Both schizophrenia and affective psychosis are associated with volumetric abnormalities at the onset of frank psychosis, with some of these evident in common brain areas.

Duration of untreated psychosis and neuropsychological function in first episode psychosis.

PURPOSE: We investigated whether duration of untreated psychosis (DUP) prior to first presentation was associated with cognitive function in first episode psychosis (FEP) subjects. We predicted that longer DUP would be associated with greater neurocognitive impairment. METHOD: 180 subjects with schizophrenia (and 93 subjects with Other Psychoses) performed a neurocognitive battery assessing IQ, verbal learning, working memory, visual learning and speed of processing. DUP was defined as the number of days between first onset of psychotic symptoms and first contact with psychiatric services. RESULTS: Longer DUP was associated with impaired performance in verbal IQ (p=0.04), verbal learning (p=0.02), and verbal working memory (p=0.04) in FEP subjects with schizophrenia. These associations remained significant for verbal IQ when scores were corrected for age, gender, educational level and ethnicity. CONCLUSIONS: Longer DUP is associated with poorer neurocognitive ability in schizophrenia subjects at time of first presentation. Since this was a cross-sectional study we can not tell whether longer DUP was a cause or a consequence of the poorer performance.

Insight in individuals with an At Risk Mental State.

PURPOSE: On average, people with an At Risk Mental State (ARMS) for psychosis are more willing to seek and accept clinical help than patients with psychotic disorders, suggesting that insight in this group is relatively less impaired. We compared the level and quality of insight in the ARMS and in first episode psychosis. MATERIALS AND METHODS: Insight about illness was assessed in subjects with an ARMS and in patients with first episode psychosis (FEP) who were and were not help-seeking, using the Schedule for Assessment of Insight (SAI-E). RESULTS: Insight was impaired in ARMS subjects, but there was considerable variability in the insight displayed between subjects. Compared to FEP subjects, ARMS subjects showed greater insight, particularly with respect to Symptom Relabelling. ARMS subjects were more likely to interpret anomalous experiences as symptoms of illness, and to perceive themselves as needing treatment. CONCLUSIONS: Insight in people at high risk for psychosis is impaired, despite the fact that they are help-seeking. Insight varies between subjects, highlighting the need to comprehensively assess all aspects of insight in those with an ARMS. ARMS subjects are impaired in their ability to appraise anomalous experiences as symptoms of illness, but much less impaired than FEP subjects. This is consistent with cognitive models that propose that the way symptoms are appraised determines whether the individual develops a psychotic illness.

Grey matter abnormalities in first-episode schizophrenia and affective psychosis.

BACKGROUND: Grey matter and other structural brain abnormalities are consistently reported in first-onset schizophrenia, but less is known about the extent of neuroanatomical changes in first-onset affective psychosis. AIMS: To determine which brain abnormalities are specific to (a) schizophrenia and (b) affective psychosis. METHOD: We obtained dual-echo (proton density/T2-weighted) magnetic resonance images and carried out voxel-based analysis on the images of 73 patients with first-episode psychosis (schizophrenia n=44, affective psychosis n=29) and 58 healthy controls. RESULTS: Both patients with schizophrenia and patients with affective psychosis had enlarged lateral and third ventricle volumes. Regional cortical grey matter reductions (including bilateral anterior cingulate gyrus, left insula and left fusiform gyrus) were evident in affective psychosis but not in schizophrenia, although patients with schizophrenia displayed decreased hippocampal grey matter and increased striatal grey matter at a more liberal statistical threshold. CONCLUSIONS: Both schizophrenia and affective psychosis are associated with volumetric abnormalities at the onset of frank psychosis, with some of these evident in common brain areas.

Insight in psychosis and neuropsychological function: meta-analysis.

BACKGROUND: One factor contributing to impaired awareness of illness (poor insight) in psychotic disorders may be neurocognitive deficits. METHOD: A systematic review and meta-analysis were conducted after data extraction. Following an overall analysis, in which measures of different cognitive domains were taken together, more fine-grained analyses investigated whether there was a specific relation with frontal executive functioning, and whether this was influenced by diagnosis or the insight scales used. RESULTS: There was a significant mean correlation between insight ratings and neurocognitive performance (mean weighted r=0.17, 95% CI 0.13-0.21, z=8.3, P<0.0001), based on 35 studies with a total of 2354 individuals. Further analyses revealed that the effect of general intellectual impairment was smaller than the specific association with executive function. This was only the case for psychosis in general, and not in an analysis limited to schizophrenia, where all cognitive domains were associated with impaired insight to a similar degree. CONCLUSIONS: Neuropsychological dysfunction, specifically impairment of set-shifting and error monitoring, contributes to poor insight in psychosis. Specific relations with different dimensions of insight and the putative role of metacognitive functions require further study.

The structural brain correlates of neurological soft signs in healthy individuals.

It has yet to be established whether neurological soft signs (NSS), which include poor motor coordination, sensory perceptual difficulties and difficulties in sequencing of complex motor tasks, result from specific or diffuse brain structural abnormalities. Studying the neuroanatomical basis of NSS in healthy individuals may help to identify which brain areas are specifically associated with these signs, while excluding the potential confounding effects of psychiatric and neurological disorders. We investigated the relationship between brain structure and NSS in 43 healthy individuals, using the Neurological Evaluation Scale for neurological assessment, and high resolution MRI and voxel-based methods of image analysis to investigate brain structure. Higher rates of NSS were associated with a reduction of inferior frontal gyrus, middle and superior temporal gyrus, and anterior cingulate gyrus. It is of note that in a previous study of patients with psychosis we found that an excess of NSS was associated with a reduction of similar cortical areas. Therefore, we suggest that these cortical brain structural changes represent a common neuroanatomical substrate of NSS, across healthy individuals and patients with psychosis.

Increased pituitary volume in antipsychotic-free and antipsychotic-treated patients of the Æsop First-Onset Psychosis Study

Subjects at their first psychotic episode show an enlarged volume of the pituitary gland, but whether this is due to hypothalamic–pituitary–adrenal (HPA) axis hyperactivity, or to stimulation of the prolactin-secreting cells by antipsychotic treatment, is unclear. We measured pituitary volume, using 1.5-mm, coronal, 1.5 T, high-resolution MRI images, in 78 patients at the first psychotic episode and 78age- and gender-matched healthy controls. In all, 18 patients were antipsychotic-free (12 of these were antipsychotic-naý¨ve), 26 werereceiving atypical antipsychotics, and 33 were receiving typical antipsychotics. As hypothesized, patients had a larger pituitary volume than controls (+22percent , p=0.001). When divided by antipsychotic treatment, and compared to controls, the pituitary volume was 15 percent larger in antipsychotic-free patients (p¼0.028), 17 percent larger in patients receiving atypicals (p¼0.01), and 30 percent larger in patients receiving typicals (p=0.001). Patients receiving typicals not only had the largest pituitary volume compared to controls but also showed a trend for a larger pituitary volume compared to the other patients grouped together (11 percent, p¼0.08). When divided by diagnosis, and compared to controls, the pituitary volume was 24 percent larger in patients with schizophrenia/schizophreniform disorder (n¼40, p=0.001), 19 percent larger in depressed patients (n¼13, p¼0.022), 16 percent larger in bipolar patients (n¼16, p¼0.037), and 12 percent larger in those with other psychoses (n¼9, p¼0.2). In conclusion, the first-episode of a psychotic disorder is associated with a larger pituitary independently of the presenceof antipsychotic treatment, and this could be due to activation of the HPA axis. Typical antipsychotics exert an additional enlarging effecton pituitary volume, likely to be related to activation of prolactin-secreting cells...