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Background: The study of hallucination-like experiences (HLEs) in non-clinical populations is increasingly used to corroborate etiological models of psychosis. This method capitalizes on the absence of confounding factors that typically affect the study of hallucinations in clinical subjects., Aim: To estimate the prevalence of HLEs in young adults; validate the mutidimensionality and explore the correlates of latent HLEs clusters., Methods: Cross-sectional survey design. The extended 16-item Launay-Slade Hallucination Scale (LSHS-E) and the 12-item General Health Questionnaire (GHQ-12) were administered to 649 Italian college students (males: 47%). Confirmatory factorial analysis was used to test multidimensionality of the LSHS-E. Hierarchical nested, progressively constrained models were used to assess configural, metric and scalar invariance of the LSHS-E. Latent class analysis was used to test the existence of different profiles of responding across the identified hallucination-proneness dimensions., Results: Factor analysis showed that the four-factor model had the best fit. Factors were invariant across demographic variables and levels of psychological distress. Three latent classes were found: a large class with no HLEs (70% of participants), a multisensory HLEs class (18.8%), and a high hallucination-proneness class (11%). Among those reporting high levels of HLEs, approximately half reported scores indicative of considerable psychological distress., Conclusions: Although HLEs have a relatively high prevalence in the general population, the majority of those experiences happen in isolation and are not associated to psychological distress. Approximately half of those individuals experiencing high levels of HLEs report significant psychological distress. This may be indicative of general risk for mental health conditions rather than specific risk for psychosis., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The underlying structures of clinical caseness and need of care in prodromal (i.e., at-risk) and early phases of schizophrenia remain poorly characterized in their essential psycho-behavioral coherence. To identify the schizophrenia proneness-related subtypes within a population of young help-seekers referred to a dedicated, community-based early detection program (Programma 2000). A sample of consecutive referrals (n = 168) for suspected psychosis or first-episode schizophrenia spectrum psychosis received a detailed clinical assessment, including the early recognition inventory for the retrospective assessment of the onset of schizophrenia checklist. We used exploratory factor analysis (EFA) to determine the underlying dimensional structure and latent class analysis (LCA) to identify putative vulnerability subtypes. EFA identified four factors: dysphoria (irritability tension), paranoid autocentrism, introversive withdrawal, and disturbed subjective experience. LCA distinguished three classes, interpretable as carrying different degrees of "proneness to schizophrenia psychosis," which best captured the underlying continuum of clinical severity. The validity of the three classes was supported by distinct patterns of association with major clinical variables (i.e., diagnostic staging at referral). Vulnerability to schizophrenia psychosis in young help-seekers may manifest in three major clinical prototypes, presenting common levels of dysphoria and social withdrawal but different degrees of paranoid autocentrism and disturbed subjective experience. Overall, the results provide the empirical background to dissect shared features of clinical caseness from more schizophrenia-specific vulnerability components. This is of value for the refinement of the clinical staging model as well as for the pragmatic implementation of multiple-gate screening programs.

Objective: Studies in the general population report that unusual subjective experiences are relatively common. Such experiences have been conceptualized either as extreme personality traits or as vulnerability markers for psychosis, and often grouped under the expression "schizotypal experiences". This study investigates the heterogeneity of schizotypal traits using factor and latent class analysis., Methods: One thousand and thirty-two adolescents were recruited for this study. Schizotypal experiences were assessed with the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE); psychological distress was assessed with the General Health Questionnaire (GHQ). Confirmatory Factorial Analysis (CFA) and Latent Class Analysis (LCA) were performed on the O-LIFE and on the association with the GHQ and demographic variables., Results: CFA replicated the original 4-factor structure of the O-LIFE. Three latent classes (LC) of schizotypal features were identified: participants in LC1 (26% of the total sample) showed minimal level of item endorsement; LC2 accounted for 52% of the sample and showed overall higher item endorsement compared to LC1, especially for disorganization and positive signs of schizotypy, but not for negative affective items. LC3 (22%) showed an overall higher level of item endorsement across schizotypal dimensions, and positive association with psychological distress and family history of psychosis., Discussion: Different latent class of schizotypal features can be empirically defined in adolescent community samples. The most extreme class is defined not only by a profile of higher positive replies to the items, but also by anhedonia, high psychological distress, and family history of psychosis. These findings can inform prevention research in schizophrenia., (Copyright © 2012 Elsevier Masson SAS. All rights reserved.)

Background and Purpose: A large number of subjective experiences and beliefs with some degree of affinity with psychotic symptoms can be found in the general population. However, the appraisal of these psychotic-like experiences in terms of associated distress, raised preoccupation, and the conviction with which the experience is held can be more discriminative in distinguishing people in need for care from those who simply hold unusual or uncommon beliefs because of cultural reasons., Method: In this study, 81 patients with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosis of schizophrenia or an affective disorder with psychotic features were compared on the Peters et al Delusions Inventory (PDI) to 210 people from the same local area, who had never received a formal diagnosis of a mental disorder., Results: Patients scored higher than controls on the PDI total score and on its distress, preoccupation, and conviction subscales. A stepwise logistic regression model showed PDI-preoccupation (odds ratio, 2.46; 95% confidence interval, 1.52-3.98) and, marginally, PDI-distress (odds ratio = 1.58; 95% confidence interval, 0.93-2.58) adding discriminative power to PDI total score in distinguishing patients from controls., Conclusions: The evaluation of the severity of delusion-like experiences and beliefs is important in discriminating patients diagnosed with psychosis from people who are not in need of care., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Despite evidence from case series, the comorbidity of eating disorders with psychosis is less investigated than their comorbidity with anxiety and mood disorders. We investigated the occurrence of symptoms of psychosis in 112 female patients diagnosed with DSM-IV eating disorders (anorexia nervosa=61, bulimia nervosa=51) and 631 high school girls in the same health district as the patients: the items of the SCL-90R symptom dimensions "paranoid ideation" and "psychoticism" were specifically examined. No case of co-morbid schizophrenia was observed among patients. Compared with controls, the patients with anorexia nervosa were more likely to endorse the item "Never feeling close to another person"; the patients with bulimia nervosa were more likely to endorse the item "Feeling others are to blame for your troubles". Both groups of patients were more likely than controls to endorse the item "Idea that something is wrong with your mind". The students who were identified by the EAT and the BITE as being "at risk" for eating disorders were more likely to assign their body a causative role in their problems. Symptoms of psychosis can be observed in patients with eating disorders, but these could be better explained within the psychopathology of the disorders rather than by assuming a link with schizophrenia., (2009 Elsevier Ltd. All rights reserved.)

Latent class analysis (LCA) has emerged as the best suitable statistical tool to identify separate dimensions (latent classes) when analyzing dichotomous data; its objective is to categorize people into classes using the observed items and to identify those items that best distinguish between classes. LCA was applied to the Peters et al. delusions inventory, an inventory in a dichotomous format (Yes/No) aimed at investigating proneness to delusion in the general population. The study involved 82 patients diagnosed with a psychotic disorder and 210 well-matched healthy controls from the community. Four classes were identified in the sample: a normative one, and 3 classes traceable to the 3 major dimensions of psychosis, i.e., paranoia, grandiosity/hypomania, and the schizophrenia-like profile. The coherent multidimensional structure of the model emerging from LCA of Peters et al. delusions inventory suggests that single clusters of symptoms may be indicative of specific diagnostic categories within the spectrum of psychoses, allowing a more subtle determination of their boundaries and correlates.