Tim Bastiaens

The Construct Validity of the Dutch Personality Inventory for DSM-5 Personality Disorders (PID-5) in a Clinical Sample:

The factor structure and the convergent validity of the Personality Inventory for DSM-5 (PID-5), a self-report questionnaire designed to measure personality pathology as advocated in the fifth edition, Section III of Diagnostic and Statistical Manual of Mental Disorders (DSM-5), are already demonstrated in general population samples, but need replication in clinical samples. In 240 Flemish inpatients, we examined the factor structure of the PID-5 by means of exploratory structural equation modeling. Additionally, we investigated differences in PID-5 higher order domain scores according to gender, age and educational level, and explored convergent and discriminant validity by relating the PID-5 with the Dimensional Assessment of Personality Pathology—Basic Questionnaire and by comparing PID-5 scores of inpatients with and without a DSM-IV categorical personality disorder diagnosis. Our results confirmed the original five-factor structure of the PID-5. The reliability and the convergent and discriminant validity of the PID-5 proved to be adequate. Implications for future research are discussed.

The Cognitive Biases Questionnaire for Psychosis (CBQ-P) and the Davos Assessment of Cognitive Biases (DACOBS): validation in a Flemish sample of psychotic patients and healthy controls.

OBJECTIVE A large body of research has demonstrated the importance of cognitive biases in the development and maintenance of psychosis. Self-report scales for routine clinical practice have been developed only recently. Two new instruments on cognitive biases are evaluated: the Cognitive Biases Questionnaire for Psychosis and the Davos Assessment of Cognitive Biases Scale. METHODS In a Flemish sample of 98 patients diagnosed with schizophrenia and 152 healthy controls, we investigated (1) the factor structure, (2) the reliability (internal consistency), (3) the discriminative power and (4) the convergent validity of the Dutch CBQ-P and the DACOBS. RESULTS Using Confirmatory Factor Analysis, a 1-factor solution provided the best fit for the CBQ-P, and a 3-factor solution for the DACOBS. The CBQ-P Total Scale and the three scales of the DACOBS showed good internal consistencies. The CBQ-P Total Scale and all three DACOBS subscales were able to differentiate between healthy controls and patients diagnosed with schizophrenia, when controlling for age and years of education. The CBQ-P and DACOBS scales showed moderate correlations, confirming the convergent validity of both scales. CONCLUSIONS The CPQ-P and DACOBS appear to be psychometrical sound instruments to assess general thinking bias in psychosis within a Flemish population. Implications for future research are discussed.

DSM-5 section III personality traits and section II personality disorders in a Flemish community sample.

The Personality Inventory for DSM-5 (PID-5; Krueger et al., 2012) is a dimensional self-report questionnaire designed to measure personality pathology according to the criterion B of the DSM-5 Section III personality model. In the current issue of DSM, this dimensional Section III personality model co-exists with the Section II categorical personality model derived from DSM-IV-TR. Therefore, investigation of the inter-relatedness of both models across populations and languages is warranted. In this study, we first examined the factor structure and reliability of the PID-5 in a Flemish community sample (N=509) by means of exploratory structural equation modeling and alpha coefficients. Next, we investigated the predictive ability of section III personality traits in relation to section II personality disorders through correlations and stepwise regression analyses. Results revealed a five factor solution for the PID-5, with adequate reliability of the facet scales. The variance in Section II personality disorders could be predicted by their theoretically comprising Section III personality traits, but additional Section III personality traits augmented this prediction. Based on current results, we discuss the Section II personality disorder conceptualization and the Section III personality disorder operationalization.

The Relationship between the Personality Inventory for the DSM-5 (PID-5) and the Psychotic Disorder in a clinical sample

Recent studies have successfully investigated the validity of the DSM-5 Alternative Model for Personality Disorders. In a final sample of 174 psychiatric patients, the present study examined the relationship between the Personality Inventory for the DSM-5 (PID-5) and syndromal psychosis. Results showed that patients diagnosed with versus without a psychotic disorder significantly differed on all PID-5 domains except Antagonism. Discriminant function analysis indicated that lower Detachment, lower Negative Affect, lower Disinhibition, and higher Psychoticism best discriminated patients with a psychotic disorder from patients with other psychiatric conditions. Subsequent stepwise discriminant analysis on all facet scales of the contributing PID-5 domains revealed that higher Unusual Beliefs, lower Depressivity, and lower Distractibility contributed the most to this differentiation. PID-5 Psychoticism scores showed moderate correlations with current psychotic symptoms and were not influenced by dose of antipsychotic medication. Our results support the ability of the PID-5 to discriminate between patients with and without psychotic disorder.