A cross-national investigation of psychosis-like experiences in five European countries included in the E-CLECTIC study: Psychometric challenges in studying their measurement.

BACKGROUND: Psychotic-like experiences (PLEs) are subtle, subclinical perturbations of perceptions and thoughts and are common in the general population. Their characterisation and unidimensionality are still debated. METHODS: This study was conducted by the Electronic-halluCinations-Like Experiences Cross-culTural International Consortium (E-CLECTIC) and aimed at measuring the Community Assessment of Psychic Experiences (CAPE) factorial structure across five European countries (Belgium; Czech Republic, Germany; Greece, and Spain) and testing the adequacy of the unidimensional polytomous Rasch model of the tool via Partial Credit Model (PCM) of the CAPE to detect people with a high risk for developing psychosis. RESULTS: The sample included 1461 participants from the general population. The factorial analysis confirmed the best fit for the bifactor implementation of the three-factor model, including the positive, negative and depressive dimensions and a general factor. Moreover, the unidimensional polytomous Rasch analysis confirmed that CAPE responses reflected one underlying psychosis proneness. CONCLUSIONS: The study proved that the CAPE measures a single latent dimension of psychosis-proneness. The CAPE might help locate and estimate psychosis risk and can be used as a screening tool in primary care settings/education settings.

Eliciting false auditory perceptions using speech frequencies and semantic priming: a signal detection approach.

INTRODUCTION: Individuals experiencing auditory hallucinations (AH) tend to perceive voices when exposed to random noise. However, the factors driving this tendency remain unclear. The present study examined the interaction of a top-down (expectations) and bottom-up (type of noise) process to better understand the mechanisms that underlie AH. METHODS: Fifty-two healthy individuals (29 with high proneness and 23 with low proneness to AH) completed a signal detection task, in which they listened to pre-recorded sentences. The last word was either masked by noise or only noise was presented without the word. Two types of noise existed (speech-related versus speech-unrelated frequencies) and words were characterised by either high or low levels of semantic expectation. RESULTS: Participants with high proneness to AH showed a more liberal decision bias (i.e., they were more likely to report having heard a word) and poorer discrimination ability as compared to participants with low proneness to AH - but only when the word was masked by speech-related noises and the level of expectation was high. Further, the more liberal decision bias correlated negatively with the tendency to experience AH. CONCLUSION: This novel paradigm demonstrated an interaction between top-down (level of expectation) and bottom-up (type of noise) processes, supporting current theoretical models of AH.

Using 360° immersive videos to assess paranoia in a non-clinical population.

Introduction: For the past two decades, virtual reality (VR) has proven to be an innovative approach for the assessment of state paranoia. However, the use of VR remains costly, and avatars are still far from realistic in terms of facial and bodily expressions. The present study aimed to test the validity of three 360° immersive videos (360IVs) as an accessible and realistic alternative for the assessment of non-clinical state paranoia.Method: Three 360IVs were created (a Lift, a Library and a Bar) and included actors behaving naturally. One hundred and fifty healthy students were assessed in terms of their proneness towards trait paranoia, were then exposed to one of the three 360IVs, and finally completed measures of state paranoia, sense of presence and cybersickness.Results: Results revealed the presence of various interpretations about the actor's attitudes in the three 360IVs. Also, paranoid thoughts were predicted by proneness towards trait paranoia in two out of the three 360IVs. Furthermore, moderate levels of sense of presence and low levels of cybersickness were observed for each 360IV.Conclusion: The present study provides evidence in favour of the use of 360IVs as a new accessible, realistic, and standardised tool to assess state paranoia in non-clinical samples.

Mapping psychotic-like experiences: Results from an online survey.

Suggestions have been made that psychotic-like experiences (PLEs), such as hallucinatory and delusional experiences, exist on a continuum from healthy individuals to patients with a diagnosis of schizophrenia. We used the screening questions of the Questionnaire for Psychotic Experiences (QPE), an interview that captures the presence and phenomenology of various psychotic experiences separately, to assess PLEs in Norway. Based on data from an online survey in a sample of more than 1,400 participants, we demonstrated that the QPE screening questions show satisfactory psychometric properties. Participants with mental disorders reported more frequent lifetime and current hallucinatory experiences than participants without mental disorders. Childhood experiences were rather low and ranged from 0.7% to 5.2%. We further replicated findings that young age, illegal drug use, lower level of education, and having parents with a mental disorder are associated with higher endorsement rates of PLEs. Finally, a binomial regression revealed that the mere presence of PLEs does not discriminate between individuals with and without a mental disorder. Taken together, the findings of the present study support existing models that both hallucinations and delusions exist on a structural and phenomenological continuum. Moreover, we demonstrated that the QPE screening questions can be used by themselves as a complementary tool to the full QPE interview.

Psychometric investigation of the French version of the Aberrant Salience Inventory (ASI): differentiating patients with psychosis, patients with other psychiatric diagnoses and non-clinical participants.

During the prodromal phase of psychosis, individuals may experience an aberrant attribution of salience to irrelevant stimuli. The concept of aberrant salience has been hypothesized to be a central mechanism in the emergence and maintenance of psychosis. The 29-item Aberrant Salience Inventory (ASI) was designed to measure five aspects of aberrant salience. The aim of this study was to investigate the psychometric properties of the French version of the ASI comparing patients with psychosis, patients with other diagnosis and healthy, non-clinical participants. The French-language ASI was adapted using the back-translation procedure. Two hundred and eighty-two participants issued from the general population and 150 psychiatric patients were evaluated. Internal validity was assessed using a two-parameter logistic item response model. Reliability was estimated using a test-retest procedure. Convergent validity was estimated using correlations between the ASI scores and several other scales. Sensitivity was evaluated by comparing the scores of participants with a diagnosis of psychosis, patients with other diagnoses and the general population. The best model distinguished three factors: Enhanced Interpretation and Emotionality, Sharpening of Senses and Heightened Cognition. Reliability and convergent validity estimates were good in both groups. The Sharpening of Senses factor was able to discriminate between patients and the general population. Only the Heightened Cognition factor was able to discriminate patients with psychosis from the other psychiatric patients. The ASI is a valid and reliable tool to study not only the aberrant salience phenomenon in patients with psychosis, but also with other diagnoses and within the general population.

Personal resilience factors protect against distressing auditory hallucinations: A study comparing psychotic patients with auditory hallucinations, non-patients with auditory hallucinations, and healthy controls.

Although studies have identified several risk factors for the development of psychotic disorders, potential protective factors - such as resilience - have rarely been examined. Studies suggest that the negative beliefs people hold about their Auditory Hallucinations (AH) may be an indicator of a need for care. However, the reason why certain people do not develop negative beliefs is unclear but may be related to resilience. The present study aimed to examine the role of resilience in AH by comparing psychotic patients with AH, non-patients with AH, and healthy controls without AH. Another aim was to explore whether resilience is related to the beliefs people hold about their AH. Results revealed that patients with AH and non-patients with AH had similarly weak interpersonal resilience factors compared to healthy controls without AH. In contrast, patients with AH showed weak personal factors of resilience compared to both non-patients with AH and healthy controls without AH. Patients with AH had more negative and fewer positive beliefs about their AH than non-patients with AH. Finally, the personal factors of resilience were related to the beliefs about AH. These results showed that personal factors of resilience are decisive variables influencing the need for care in people experiencing AH and thus represent an important treatment target.

Testing a model of auditory hallucinations: the role of negative emotions and cognitive resources.

Introduction: Models of auditory hallucinations (AH) state that AH arise through an interaction between negative emotions and limited available cognitive resources. However, this hypothesis has never been directly tested. Methods: A two-by-two factorial design was used to examine the effect of emotions (neutral VS negative) and available cognitive resources (high VS low) on the elicitation of false alarms in an auditory signal detection paradigm. One hundred and seventy four healthy participants were assigned to one of the four experimental conditions. While participants were listening to white noise, their emotional state was manipulated using affective pictures and the level of available cognitive resources was manipulated using a visual N-back task. Results: Results revealed significant interaction effects between emotions and cognitive resources on the number of false alarms. In particular, participants with fewer available cognitive resources and at the same time who were in a negative emotional state, tended to hear significantly more false alarms. In addition, the degree of certitude was significantly correlated with a higher degree of hallucination proneness. Conclusions: Such results are in agreement with models of AH and they provide new data for the understanding of the emotional and cognitive mechanisms that underpin AH.

An epidemiological study on the prevalence of hallucinations in a general-population sample: Effects of age and sensory modality.

Epidemiological studies have repeatedly shown that a significant minority of the general population have experienced hallucinations, however, a potential effect of age on the prevalence of hallucinations in the general population has never been previously examined in a specific study. The aim of the present study was thus to examine the effects of age and sensory modality on hallucination prevalence in a general population sample. A large, randomly selected and representative sample of the Norwegian population completed measures assessing different hallucination modalities (auditory, visual, olfactory, and tactile) and types (sensed presence and hypnagogic/hypnopompic hallucinations). Three age groups were identified and compared: young (19-30 years), middle (31-60) and old (61-96). There was a significant main-effect of age for all hallucination modalities and types, whereby hallucination prevalence significantly decreased with age. We also found that anxiety partially mediated the effect of age on hallucinations whilst depression was a partial suppressor. Concerning the co-occurrence of hallucination modalities, there was very little co-occurrence of auditory and visual hallucinations in all three age groups. In summary, a main-effect of age for hallucination prevalence was observed. Furthermore, individuals reported a more diverse variety of hallucination modalities compared to what is commonly reported in clinical populations.

Potential Applications of Digital Technology in Assessment, Treatment, and Self-help for Hallucinations.

The field of digital mental health is rapidly expanding with digital tools being used in assessment, intervention, and supporting self-help. The application of digital mental health to hallucinations is, however, at a very early stage. This report from a working group of the International Consortium on Hallucinations Research considers particular synergies between the phenomenon of hallucinations and digital tools that are being developed. Highlighted uses include monitoring and managing intermittently occurring hallucinations in daily life; therapeutic applications of audio and video media including virtual and augmented reality; targeting verbal aspects of hallucinations; and using avatars to represent hallucinatory voices. Although there is a well-established Internet-based peer support network, digital resources for hallucinations have yet to be implemented in routine practice. Implementation may benefit from identifying how to market resources to the broad range of populations who experience hallucinations and identifying sustainable funding models. It is envisaged that digital tools will contribute to improved self-management and service provision for people experiencing hallucinations.

A Cross-National Investigation of Hallucination-Like Experiences in 10 Countries: The E-CLECTIC Study.

Hallucination-like experiences (HLEs) are typically defined as sensory perceptions in the absence of external stimuli. Multidimensional tools, able to assess different facets of HLEs, are helpful for a better characterization of hallucination proneness and to investigate the cross-national variation in the frequencies of HLEs. The current study set out to establish the validity, factor structure, and measurement invariance of the Launay-Slade Hallucinations Scale-Extended (LSHS-E), a tool to assess HLEs. A total of 4419 respondents from 10 countries were enrolled. Network analyses between the LSHS-E and the 3 dimensions of the Community Assessment of Psychic Experiences (CAPE) were performed to assess convergent and divergent validity of the LSHS-E. Confirmatory factor analysis was used to test its measurement invariance. The best fit was a 4-factor model, which proved invariant by country and clinical status, indicating cross-national stability of the hallucination-proneness construct. Among the different components of hallucination-proneness, auditory-visual HLEs had the strongest association with the positive dimension of the CAPE, compared with the depression and negative dimensions. Participants who reported a diagnosis of a mental disorder scored higher on the 4 LSHS-E factors. Small effect size differences by country were found in the scores of the 4 LSHS-E factors even after taking into account the role of socio-demographic and clinical variables. Due to its good psychometric properties, the LSHS-E is a strong candidate tool for large investigations of HLEs.

No sex difference in an everyday multitasking paradigm.

According to popular beliefs and anecdotes, females best males when handling multiple tasks at the same time. However, there is relatively little empirical evidence as to whether there truly is a sex difference in multitasking and the few available studies yield inconsistent findings. We present data from a paradigm that was specifically designed to test multitasking abilities in an everyday scenario, the computerized meeting preparation task (CMPT), which requires participants to prepare a room for a meeting and handling various tasks and distractors in the process. Eighty-two males and 66 females with a wide age range (18-60 years) and a wide educational background completed the CMPT. Results revealed that none of the multitasking measures (accuracy, total time, total distance covered by the avatar, a prospective memory score, and a distractor management score) showed any sex differences. All effect sizes were d ≤ 0.18 and thus not even considered "small" by conventional standards. The findings are in line with other studies that found no or only small gender differences in everyday multitasking abilities. However, there is still too little data available to conclude if, and in which multitasking paradigms, gender differences arise.

Source flexibility in schizophrenia: specificity and role in auditory hallucinations.

INTRODUCTION: One important aspect of human cognition relies on the ability to bias attention towards stimulus-independent and stimulus-oriented thoughts and to switch between these states - or source flexibility. This mechanism has received very little attention in the literature, and in particular in schizophrenia. Moreover, there is good reason to believe that this mechanism could also be implicated in hallucinations, but this hypothesis has never been examined. Thus, the aim of the present study was, for the first time in the literature, to explore source flexibility abilities in schizophrenia and their potential relations with auditory hallucinations. METHODS: Forty persons diagnosed with schizophrenia and 26 healthy controls were evaluated with tasks assessing source flexibility, cognitive flexibility and processing speed. Patients were also assessed with a measure of hallucinations and delusions. RESULTS: Results revealed that persons diagnosed with schizophrenia presented a poorer performance than healthy controls for source flexibility. Moreover, results demonstrated that source flexibility performance could not be explained by a more general impairment of processing speed or buy difficulties in cognitive flexibility. Finally, source flexibility was found to be related to hallucinations. CONCLUSIONS: Source flexibility plays an important role in schizophrenia and in particular is a cognitive mechanism involved in hallucinations.

Attribution of intentions and context processing in psychometric schizotypy.

INTRODUCTION: Impairment in Theory of mind (TOM) has frequently been associated with schizophrenia and with schizotypy. Studies have found that a tendency to over-attribute intentions and special meaning to events and to people is related to positive psychotic symptoms. Further, it has been suggested that this intentionality bias may be due to a broader deficit in context processing (CP). The aim of the present study was thus to investigate the relationship between positive schizotypy and both over-attribution of intentions and contextual processing. METHODS: One-hundred and nineteen healthy individuals completed the Schizotypal Personality Questionnaire and were assessed with tasks measuring contextual treatment and ToM. RESULTS: Results revealed that positive schizotypy was significantly related to an over-attribution of intentions on the ToM task and with a faster processing of implicit context. Partial correlational analyses indicated that the association between the attribution of intentions and positive schizotypy was not explained by a deficit of CP. In contrast, stepwise multiple regression analyses showed that both an over-attribution of intentions and a faster processing of implicit context significantly predicted positive schizotypy. CONCLUSIONS: These results show that an over-attribution of intention is independent from a broader deficit in context information processing and that they both possibly contribute to the development and maintenance of positive psychotic symptoms.

A direct examination of the cognitive underpinnings of multitasking abilities: A first study examining schizophrenia.

Many real world activities are complex and require multitasking abilities. However, the nature of these abilities remains poorly understood, and in particular in schizophrenia. The aim of the present study was to provide a better understanding of such abilities with the help of a newly developed computerized tool, the Computerized Meeting Preparation Task (CMPT). Fifty-seven individuals with schizophrenia and 39 healthy controls completed the CMPT and an extensive cognitive battery. Patients were also evaluated with a series of clinical measures. During the CMPT, participants are asked to prepare a room for a meeting while, at the same time, dealing with interruptions, solving problems, and remembering prospective memory instructions. The CMPT was found to significantly differentiate patients and healthy controls for several variables. Results also showed that multitasking abilities were related to a large array of cognitive functions and, in particular, to those associated to executive functioning. These relations were not explained by the presence of a general cognitive impairment. Finally, a double dissociation between multitasking abilities and performance on standard cognitive tests was observed. Altogether, these results underline the importance of evaluating multitasking abilities in schizophrenia as it allows detecting cognitive difficulties that cannot be identified by standard cognitive tests.

Subtyping attenuated psychotic symptoms: A cluster analytic approach.

OBJECTIVE: The aim of the present study is to examine the heterogeneity of attenuated psychotic symptoms (PS) and related personality factors using a cluster analytic approach. METHOD: A large sample of participants from the general population was evaluated in terms of attenuated symptomatology (psychotic and affective) and two personality factors: encoding style and impulsivity traits. RESULTS: Cluster analysis emphasized the existence of five independent clusters: High Psychosis, High Positive, High Negative, High Impulsive-Low Psychosis, and Low Psychosis. Cluster comparisons demonstrated that the personality factors and PS are differentially involved in the clusters. CONCLUSIONS: The present study demonstrated that reliable and relatively distinct clusters of individuals from the general population can be identified based on established PS and related personality factors. The fact that a variety of profiles was observed contributes to a better understanding of the nature of the heterogeneity characterizing PS and has clear theoretical and clinical implications.

The Network Structure of Schizotypal Personality Traits.

Elucidating schizotypal traits is important if we are to understand the various manifestations of psychosis spectrum liability and to reliably identify individuals at high risk for psychosis. The present study examined the network structures of (1) 9 schizotypal personality domains and (2) 74 individual schizotypal items, and (3) explored whether networks differed across gender and culture (North America vs China). The study was conducted in a sample of 27001 participants from 12 countries and 21 sites (M age = 22.12; SD = 6.28; 37.5% males). The Schizotypal Personality Questionnaire (SPQ) was used to assess 74 self-report items aggregated in 9 domains. We used network models to estimate conditional dependence relations among variables. In the domain-level network, schizotypal traits were strongly interconnected. Predictability (explained variance of each node) ranged from 31% (odd/magical beliefs) to 55% (constricted affect), with a mean of 43.7%. In the item-level network, variables showed relations both within and across domains, although within-domain associations were generally stronger. The average predictability of SPQ items was 27.8%. The network structures of men and women were similar (r = .74), node centrality was similar across networks (r = .90), as was connectivity (195.59 and 199.70, respectively). North American and Chinese participants networks showed lower similarity in terms of structure (r = 0.44), node centrality (r = 0.56), and connectivity (180.35 and 153.97, respectively). In sum, the present article points to the value of conceptualizing schizotypal personality as a complex system of interacting cognitive, emotional, and affective characteristics.

Comparisons of schizotypal traits across 12 countries: Results from the International Consortium for Schizotypy Research.

BACKGROUND: Schizotypal traits are expressions of underlying vulnerability to psychotic disorders which have a potential impact on mental health status, neurocognition, quality of life, and daily functioning. To date, little research has examined epidemiologic landscape of schizotypal traits at the cross-national level. Our aim was to study the expression of schizotypal traits by sex, age, and country in a combined sample gathered from 12 countries. METHODS: A total of 27,001 participants completed the Schizotypal Personality Questionnaire (SPQ). The mean age of participants was 22.12 (SD=6.28); 37.5% (n=10,126) were males. RESULTS: Schizotypal traits varied according to sex, age, and country. Females scored higher than males in the positive dimension, whereas males scored higher in the disorganization dimension. By age, a significant decrease in the positive schizotypal traits was observed. Epidemiological expression of schizotypal traits varied by country. Moreover, several interactions by sex, age, and country were found. CONCLUSIONS: This pattern is similar to those found in patients with psychosis and psychotic-like experiences. These findings provide new insights and the opportunity to explore the phenotypic expression of schizotypal traits at cross-national level.

Do adverse life events at first onset of auditory verbal hallucinations influence subsequent voice characteristics? Results from an epidemiological study.

Understanding what happens at first onset of auditory verbal hallucinations (AVHs) is extremely important on a clinical and theoretical level. Previous studies have only focused on age with regard to first onset of AVHs. In the current epidemiological study, we examined a number of aspects relating to first onset of AVHs, such as the role of adverse life events at first onset of AVHs on symptom severity and general mental health. For this purpose, we compared participants who reported adverse life events at first onset of AHVs (adverse-trigger group; N = 76) to those that did not report any specific events at first onset of AVHs (no-adverse-trigger group; N = 59) on a large array of variables. Results showed that AVHs in the adverse-trigger group were experienced as more emotional compared to the no-adverse-trigger group. In addition, the adverse-trigger group more often reported hallucinations in other (non-auditory) sensory modalities (e.g. visual) compared to the no-adverse-trigger group. Furthermore, the adverse-trigger group reported poorer general mental health, reported having contact with mental health professionals more often, and also reported more frequently taking medication for psychological problems in general. The implications of these findings are discussed.