Specificity of jumping to conclusions and attributional biases: a comparison between patients with schizophrenia, depression, and anorexia nervosa.

INTRODUCTION: The knowledge of the specificity of cognitive biases in psychiatric disorders is important in order to develop disorder-specific cognitive models and therapies. This cross-sectional study aimed to investigate the specificity of jumping to conclusions (JTC) and attributional biases (AB) for patients with schizophrenia.
METHODS: Twenty patients with paranoid schizophrenia were compared with patients with depression (n=20) and with anorexia nervosa (n=15) and nonclinical controls (n=55). All participants were administered a modified version of the beads task (JTC), a revised German version of the Internal, Personal, and Situational Attributions Questionnaire (AB), and several symptom and neurocognitive measures.
RESULTS: The proportion of patients with JTC bias in the schizophrenia group was, at the descriptive level, higher than in the depression and the anorexia groups. Regarding AB, the schizophrenia group showed a significantly stronger externalising but not personalising bias than the clinical control groups. Neither JTC nor attributional biases were significantly associated with delusions in general or persecutory delusion.
CONCLUSIONS: We found evidence for the specificity of an externalising bias for paranoid schizophrenia. Concerning JTC bias the evidence was less clear. Whether the modification of those biases through psychological interventions would have an effect on psychopathology should be investigated in the context of clinical trials.