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.

Clinical determinants of involuntary psychiatric hospitalization: A clinical profile approach.

OBJECTIVES: The study examines the clinical determinants of involuntary psychiatric hospitalization. Specifically, it investigates whether distinct clinical profiles of hospitalized patients can be discerned, what other characteristics they are linked with, and which profiles predict involuntary admission. METHODS: In this cross-sectional multicentre population study, data were collected for 1067 consecutive admissions in all public psychiatric clinics of Thessaloniki, Greece, during 12 months. Through Latent Class Analysis distinct patient clinical profiles were established based on Health of the Nation Outcome Scales ratings. The profiles were then correlated with sociodemographic, other clinical, and treatment-related factors as covariates and admission status as a distal outcome. RESULTS: Three profiles emerged. The "Disorganized Psychotic Symptoms" profile, combining positive psychotic symptomatology and disorganization, included mainly men, with previous involuntary hospitalizations and poor contact with mental health services and adherence to medication, indicating a deteriorating condition and chronic course. Τhe "Active Psychotic Symptoms" profile included younger persons with positive psychotic symptomatology in the context of normal functioning. The "Depressive Symptoms" profile, characterized by depressed mood coupled with nonaccidental self-injury, included mainly older women in regular contact with mental health professionals and treatment. The first two profiles were associated with involuntary admission and the third with voluntary admission. CONCLUSIONS: Identifying patient profiles allows the examination of the combined effect of clinical, sociodemographic, and treatment-related characteristics as risk factors for involuntary hospitalization, moving beyond the variable-centered approach mainly adopted to date. The identification of two profiles associated with involuntary admission necessitates the development of interventions tailored to chronic patients and younger persons suffering from psychosis respectively.

Short-term reliability of retrospective childhood trauma reports in schizophrenia spectrum psychosis.

Childhood trauma (CT) refers to severe early life adversities, especially experiences of parental abuse and neglect. Patients with schizophrenia spectrum psychosis (SSP) report higher CT rates than the general population. As CT assessment in SSP samples has been mainly conducted retrospectively through adult recollections of childhood adverse events, reservations about the reliability and validity of these reports have arisen. We sought to explore the short-term reliability of retrospective CT reports in sixty-three patients with SSP, by assessing the concurrent validity and test-retest reliability of the data. Two CT self-report measures, the Childhood Experience of Care and Abuse Questionnaire (CECA.Q) and the Parental Bonding Instrument (PBI) were employed for this task. High concurrent validity was detected between CECA.Q antipathy scales and PBI care and overprotection scales; and between CECA.Q neglect scales and PBI care scales. High test-retest reliability was confirmed for all CECA.Q and PBI scales. Our findings indicate that retrospective CT self-report measures are a reliable means of assessing early life adversities in SSP. However, further provisions should be taken to increase the reliability of retrospective reports, especially corroboration of the events through other sources and removal of latent confounders, such as psychopathology, memory fallacies and social desirability biases.

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.

ABCB1 and CYP2D6 polymorphisms and treatment response of psychotic patients in a naturalistic setting.

OBJECTIVES: The aim of our study was to examine the association between ABCB1 polymorphisms G2677T/A (rs2032582) and C3435T (rs1045642) and common CYP2D6 variants, with the response to antipsychotic treatment of psychotic patients, in a naturalistic setting, in Greece. METHODS: One hundred patients suffering from schizophrenia and other psychotic disorders were included in the study. Dosages were normalized to chlorpromazine equivalents. Response following 1 month of treatment was assessed as either a continuous variable, using the distribution of the corrected Positive and Negative Syndrome Scale percent change, or as a dichotomous variable defined as the number of patients scoring ≥30% from the corrected baseline Positive and Negative Syndrome Scale score. Genotyping was achieved with established polymerase chain reaction-restriction fragment length polymorphism methods. RESULTS: With response treated as a continuous variable, the homozygous recessive rs2032582 genotypes (TT) who were simultaneously carriers of a loss-of-function CYP2D6 allele (*4 or *5) responded significantly worse than the rest of the patients. Comparison of genotype frequencies revealed a statistically significant association of the above combination. No significant association between chlorpromazine equivalents and the tested genotypes was detected. CONCLUSION: We have detected a possible interaction between ABCB1 and CYP2D6 in affecting response of psychotic patients to drug treatment, in a naturalistic setting.