The relationship between jumping to conclusions and neuropsychological functioning in schizophrenia

Jumping to conclusions (JTC) is defined as a tendency to make decisions based on insufficient information. JTC has been reported in patients with psychosis, but the mechanisms of this cognitive bias remain unknown. The main aim of our study was to investigate the relationship between JTC and neuropsychological functioning in schizophrenia. A total of 85 schizophrenia patients were assessed with neuropsychological tests, including executive functions, verbal memory, working memory, processing speed and attention. JTC was assessed with the Fish Task (probability 80:20 and 60:40) and a self-report scale (The Davos Assessment of Cognitive Biases Scale, DACOBS). Symptom severity was assessed with the Positive and Negative Syndrome Scale (PANSS). The relationship between JTC and neuropsychological functioning was investigated with correlation and regression analyses. The regression analyses model, when controlling for duration of illness, age and symptoms, showed that verbal memory and working memory were specifically related to JTC measured by Fish Task 60:40. JTC measured using Fish Task 60:40 was correlated only with severity of symptoms of disorganization (PANSS). The results from the present study suggest that the relationship between decision making during the reasoning task and neuropsychological functioning is modulated by task demands.