Reliability and normative data of the Perceptual Aberration Scale in an Italian juvenile general population sample

Complex Bodily Hallucinatory Experiences Scale (CBHES): Development, structure and psychometric properties

OBJECTIVES

Complex bodily hallucinations are not rare in psychiatric, neurological and toxicological conditions and may also be reported even in the total absence of any medical condition. Despite this, they are usually not clinically assessed independently from (and in comparison to) hallucinations in other modalities. The objective of this study was to develop a short scale assessing complex bodily hallucinations.

METHODS

Based on previous research and clinical reports, we present a new short scale for the assessment of four themes of such hallucinations, i.e., delusional parasitosis, the feeling of presence, autoscopic phenomena, and body distortions. The scale was completed by 623 participants from the general population.

RESULTS

Complex bodily hallucinations are frequent, with 96.6% of the sample reporting at least one. A Confirmatory Factor Analysis showed that the data best fit a hierarchical model in which the four independent themes are linked to a higher-order factor that we tentatively identifed as bodily self-consciousness. Each one of the four themes was reported in isolation in less than 5% of the sample, but combinations of themes were more frequent. The scale has good internal consistency, a good 3-month test-retest reliability, and good convergent validity. Furthermore, the scale has a good balance between specificity and sensitivity when the 90th percentile of the total score is used as a classification criterion.

CONCLUSION

The short scale developed has good psychometric properties and can be used both in clinical and research settings.

Exploring the effects of family and life events on genetic and environmental architecture of schizotypal and hypomanic dimensions: Insights from a twin study

BACKGROUND

Strategies of prevention for psychiatric disorders need a deep understanding of the aetiological factors involved in the psychopathological processes. Our twin study aims at disentangling the contributions of genes and environment to schizotypal and hypomanic dimensions, considering the role of stressful life events (LEs) and the quality of family relationships.

METHODS

The Magical Ideation Scale (MIS) and Perceptual Aberration Scale (PAS) were used to assess positive schizotypy, while Hypomanic Personality Scale (HPS) and its sub-scales were used to investigate proneness to affective disorders. 268 twins (54.5 % female; aged 18.0 ± 6.68) were included. Participants filled out a questionnaire on LEs and their parents provided an evaluation of intra-family relationship (Relationship Quality Index, RQI). Classic univariate twin models for quantitative traits were fitted for scales, and the effects of covariates (LEs and RQI) were assessed.

RESULTS

For MIS, HPS and its sub-scales, significant common and unique environmental effects were detected, with genetic factors affecting only HPS Social Vitality sub-scale. Unique environment was the only source of variance of PAS score. The number of recent LEs influenced MIS and PAS models, while RQI score affected MIS model.

LIMITATIONS

The main limitation of the study is the small sample size, which reduces statistical power and may potentially lead to an underestimation of heritability. Additionally, the cross-sectional design limits the possibility to draw causal considerations.

CONCLUSIONS

Findings provide preliminary evidence for a significant environmental role in modulating states of vulnerability. Moreover, the expression of positive schizotypy resulted influenced by recent stressors and intra-family relationships.

Examining measures of schizotypy for gender and racial bias using item response theory and differential item functioning

Schizotypy involves schizophrenia-like traits and symptoms, with the Wisconsin Schizotypy Scales (WSS) being frequently used in previous research. There is some evidence that schizophrenia-spectrum symptom levels, including when using the WSS, might vary both by gender and by race and ethnicity. However, previous research has rarely examined to what extent the WSS show gender and racial bias. Further, this has not been previously examined for the Cognitive Slippage Scale, a measure of disorganized schizotypy. In this study, we examined biases for a subset of items from the WSS in a large sample of undergraduate students (n = 21,829). Using item response theory to test for levels of differential item functioning (DIF), we found some evidence of problematic DIF for all scales, including for negative, positive, and disorganized schizotypy scales. There was evidence of problematic DIF especially by gender and for Black and Multiracial participants. Overall, the current results suggest that gender and/or racial bias on these scales should be an important consideration in using these scales and our results could have implications for assessment of schizophrenia-spectrum symptoms.

Brief rapport: Perceptual aberration in patients at ultra-high risk for psychosis

BACKGROUND

Ultra-high risk (UHR) is considered a forerunner of psychosis, but most UHR individuals do not later convert, yet remain symptomatic, disabled and help-seeking. Thus, there is an increased recognition of the UHR phenotype as a syndrome in itself, rather than merely a risk syndrome. It is therefore essential to investigate outcomes other than transition to psychosis. For this purpose, perceptual aberration appears to be a distinct, as well as a stable and less state-specific vulnerability indicator. We aimed to investigate perceptual aberration and associations with functional, neuro and social cognitive risk factors in an UHR sample.

METHOD

One hundred and twenty UHR and 64 healthy controls were compared on levels of perceptual aberration using the perceptual aberration scale. We further investigated cross-sectional associations between perceptual aberration and CAARMS (as a measure of subthreshold psychotic symptoms) and functional, neuro and social cognitive risk factors within the UHR using Spearmans ρ.

RESULTS

Perceptual aberration was significantly higher in UHR than in healthy controls and was associated with social functioning, executive functioning, and emotion recognition.

CONCLUSION

Our findings are consistent with a view of perceptual aberration as a stable vulnerability indicator that varies little with clinical state.

Aberrant Salience Inventory: A meta-analysis to investigate its psychometric properties and identify screening cutoff scores

INTRODUCTION

The Aberrant Salience Inventory (ASI) is a useful tool to measure salience abnormalities among the general population. There is strong clinical and scientific evidence that salience alteration is linked to psychosis. To the present day, no meta-analysis evaluating ASI's psychometric properties and screening potential has been published.

MATERIALS AND METHODS

PubMed, Google Scholar, Scopus, and Embase were searched using terms including "psychosis," "schizophrenia," and "Aberrant Salience Inventory." Observational and experimental studies employing ASI on populations of non-psychotic controls and patients with psychosis were included. ASI scores and other demographic measures (age, gender, ethnicity) were extracted as outcomes. Individual patients' data (IPD) were collected. Exploratory factor analysis (EFA) was performed on the IPD.

RESULTS

Eight articles were finally included in the meta-analysis. ASI scores differ significantly between psychotic and non-psychotic populations; a novel three-factor model is proposed regarding subscales structure. Theoretical positive predictive values (PPVs) and negative predictive values (NPVs) were calculated and presented together with different cutoff points depending on preselected specific populations of interest.

DISCUSSION

PPV and NPV values reached levels adequate for ASI to be considered a viable screening tool for psychosis. The factor analysis highlights the presence of a novel subscale that was named "Unveiling experiences." Implications regarding the meaning of the new factor structure are discussed, as well as ASI's potential as a screening tool.

Transition Between Sensitive Delusion of Reference and Mood Disorder: A Case Report

The Sensitive Delusion of Reference is a clinical entity described by Ernst Kretschmer and never integrated into mainstream nosographic systems. It represents the possibility of developing psychosis starting from a personality characterized by sensitivity, scrupulousness, and fear of judgment of others. The presentation of the following clinical case highlights how the overlap between this clinical entity and mood disorders leads to characteristic psychopathology, which has not been sufficiently detailed. In particular, the delusions, which always starts from the idea of reference and the shame in the face of the judgment of others, takes on characteristics of guilt during the depressive phases and persecutory themes during the activation phases. This clinical observation, which obviously needs to be confirmed on a larger scale, encourages a renewed interest in the concept of Kretschmer's Sensitive Delusion of Reference and creates the possibility of intersecting multiple psychopathological levels, for a more complete perspective on the individual case.

Case Report: The Association Between Chromosomal Anomalies and Cluster A Personality Disorders: The Case of Two Siblings With 16p11.2 Deletion and a Review of the Literature

Although several studies have shown the correlation between chromosomal rearrangements and the risk of developing psychotic disorders, such as schizophrenia, little attention has been given to identifying the genetic basis of pre-disposing personality so far. In this regard, a limited but significant number of studies seem to indicate an association between chromosomal anomalies and cluster A personality disorders (CAPD). Starting from the clinical description of two brothers affected by familial 16p11 deletion syndrome (OMIM #611913), both sharing cluster A and C personality traits, the aim of the present study is to critically review the literature regarding the correlation between chromosomal rearrangements and CAPD. A bibliographic search on PubMed has been conducted, and eight studies were finally included in our review. Most of the studies highlight the presence of schizotypal personality disorder in the 22q11.2 deletion syndrome, whose evolutionary course toward psychotic pictures is well-known. One study also identified a paranoid personality disorder in a patient with a deletion on chromosome 7q21.3. No studies have so far identified the presence of paranoid personality disorder in 16p11 deletion, as in the case of the two siblings we report, while its association with psychosis and autism is already known. Although further epidemiologic studies on broader populations are indicated, our observations might pave the way for the definition of new diagnostic subgroups of CAPD and psychotic disorders, in order to implement the clinical management of such complex conditions.

The mental simulation of state/psychological verbs in the adolescent brain: An fMRI study

This fMRI study investigated mental simulation of state/psychological and action verbs during adolescence. Sixteen healthy subjects silently read verbs describing a motor scene or not (STIMULUS: motor, state/psychological verbs) and they were explicitly asked to imagine the situation or they performed letter detection preventing them from using simulation (TASK: imagery vs. letter detection). A significant task by stimuli interaction showed that imagery of state/psychological verbs, as compared to action stimuli (controlled by the letter detection) selectively increased activation in the right supramarginal gyrus/rolandic operculum and in the right insula, and decreased activation in the right intraparietal sulcus. We compared these data to those from a group of older participants (Tomasino et al. 2014a). Activation in the left supramarginal gyrus decreased for the latter group (as compared to the present group) for imagery of state/psychological verbs. By contrast, activation in the right superior frontal gyrus decreased for the former group (as compared to the older group) for imagery of state/psychological verbs.

Normative data of the Magical Ideation Scale from childhood to adulthood in an Italian cohort

The assessment of schizotypy allows to identify people at risk to develop psychosis. For this purpose, psychometric tools have been developed, such as the Magical Ideation Scale (MIS). This scale investigates attenuated forms of thought transmission experiences, thought withdrawal and aberrant beliefs, related to positive schizotypy. This study aims at providing an Italian version of the MIS and its normative data in the general population from childhood to adulthood, being the first study evaluating subjects under 17year-old. The Italian MIS version was translated by three independent operators and administered to 1378 non-clinical participants, stratified into four age groups (i.e., 8-13, 14-17, 18-24 and 25-34). The unidimensionality of the scale was supported, and its internal consistency was satisfactory (i.e., ordinal Cronbach's αs ranging from 0.86 to 0.90 in different age groups), as well as test-retest reliability (i.e., 1-month ICC of 0.82 in a retested sub-sample). Normative data for the age groups were provided. Specific gender and age-related differences in MIS score were found, i.e. females scored higher than males in the 25-34 age group, which in general, as a group, scored lower than all the other age groups. This study provided evidence of reliability for the Italian version of the MIS in childhood and adolescence, for the first time, as well as in adulthood, showing specific gender and age effects in the early adult cohort.