Cognitive biases are associated with clinical and functional variables in psychosis: A comparison across schizophrenia, early psychosis and healthy individuals

Cognitive biases in first-episode psychosis with and without attention-deficit/hyperactivity disorder

Introduction

Psychotic disorders such schizophrenia and attention-deficit/hyperactivity disorder (ADHD) are neurodevelopmental disorders with social cognitive deficits. Specifically, biased interpretation of social information can result in interpersonal difficulties. Cognitive biases are prevalent in psychosis, but no previous study has investigated whether the type and severity of cognitive biases differ between subjects experiencing first-episode psychosis (FEP) with (FEP-ADHD⁺) and without ADHD (FEP-ADHD^-).

Methods

A total of 121 FEP outpatients at the Early Intervention Service of Reus were screened for childhood ADHD through the Diagnostic Interview for ADHD (DIVA). Cognitive biases were assessed by the Cognitive Biases Questionnaire for Psychosis (CBQp). CBQp scores of FEPs groups were compared with those of healthy controls (HCs) with an analysis of covariance. Spearman correlation analysis explored associations between CBQp scores and psychopathology.

Results

Thirty-one FEPs met the criteria for childhood ADHD and reported significantly more cognitive bias [median (interquartile range): 47 (38-56)] than FEP-ADHD^- [42 (37-48)] and HCs [38 (35.5-43)]. CBQp scores did not differ between FEP-ADHD-and HCs when adjusted for age and sex. After controlling for clinical differences, Intentionalising (F = 20.97; p < 0.001) and Emotional Reasoning biases (F = 4.17; p = 0.04) were more strongly associated with FEP-ADHD⁺ than FEP-ADHD^-. Cognitive biases were significantly correlated with positive psychotic symptoms in both groups but only with depressive symptoms in FEP-ADHD^- (r = 0.258; p = 0.03) and with poor functioning in FEP-ADHD⁺ (r = -0.504; p = 0.003).

Conclusion

Cognitive bias severity increased from HCs to FEP-ADHD-patients to FEP-ADHD⁺ patients. FEP-ADHD⁺ patients may be a particularly vulnerable group in which metacognitive targeted interventions are needed.

Self-reported cognitive biases in psychosis: Validation of the Davos Assessment of Cognitive Biases Scale (DACOBS) in a Spanish sample of psychotic patients and healthy controls

Cognitive biases have been demonstrated to be important in developing and maintaining psychosis. However, self-report measures for everyday clinical practice have been developed only recently. We aimed to study one of these instruments for assessing cognitive biases: the Davos Assessment of Cognitive Biases Scale (DACOBS). In a Spanish sample of 84 patients diagnosed with schizophrenia-spectrum disorders and 152 healthy controls, we examined a) the factor structure using Confirmatory Factor Analysis (CFA) to test the original one-, three- and seven-factor solutions, b) the reliability (Cronbach's alpha), c) the discriminative power (Multivariate Analysis of Covariance - MANCOVA) and d) the relationships of cognitive biases with positive psychotic-like experiences (PPLEs) in healthy individuals and with psychotic symptoms in schizophrenia-spectrum patients. The CFA revealed that the seven-factor solution achieved the best fit. The DACOBS overall scale (Cronbach's alpha = .92) and subscales obtained good internal consistencies. MANCOVA, controlling for age and education, demonstrated that all subscales differentiated between healthy controls and psychotic patients (Wilks' Lambda = 0.87; F_{7, 226} = 4.70; p < .000; partial eta squared = 0.13). In addition, the DACOBS showed high correlations with PPLEs (controls) and moderate correlations with positive and general symptoms (patients), demonstrating its predictive validity. Concluding, the DACOBS proved to be a psychometrically suitable instrument for assessing cognitive biases in psychosis and adequately differentiated between patients and healthy individuals within the Spanish population. Norm scores are provided.