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

Objective: We investigated the presence of cognitive biases in people with a recent-onset psychosis (ROP), schizophrenia and healthy adolescents and explored potential associations between these biases and psychopathology.

Methods: Three groups were studied: schizophrenia (N=63), ROP (N=43) and healthy adolescents (N=45). Cognitive biases were assessed with the Cognitive Biases Questionnaire for Psychosis (CBQ). Positive, negative and depressive symptoms were assessed with the PANSS and Calgary Depression Scale (ROP; schizophrenia) and with the CAPE-42 (healthy adolescents). Cannabis use was registered. The association between CBQ and psychopathology scales was tested with multiple linear regression analyses.

Results: People with schizophrenia reported more cognitive biases (46.1±9.0) than ROP (40±5.9), without statistically significant differences when compared to healthy adolescents (43.7±7.3). Cognitive biases were significantly associated with positive symptoms in both healthy adolescents (Standardized β=0.365, p=0.018) and people with psychotic disorders (β=0.258, p=0.011). Cognitive biases were significantly associated with depressive symptoms in healthy adolescents (β=0.359, p=0.019) but in patients with psychotic disorders a significant interaction between schizophrenia diagnosis and CBQ was found (β=1.804, p=0.011), which suggests that the pattern differs between ROP and schizophrenia groups (positive association only found in the schizophrenia group). Concerning CBQ domains, jumping to conclusions was associated with positive and depressive symptoms in people with schizophrenia and with cannabis use in ROP individuals. Dichotomous thinking was associated with positive and depressive symptoms in all groups.

Conclusions: Cognitive biases contribute to the expression of positive and depressive symptoms in both people with psychotic disorders and healthy individuals.