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.