Stress is a bad advisor. Stress primes poor decision making in deluded psychotic patients.

Stress is implicated in the onset of psychosis but the complex links between stress and psychotic breakdown are yet poorly understood. For the present study, we examined whether two prominent cognitive biases in psychosis, jumping to conclusions and distorted attribution, in conjunction with neuropsychological deficits play a role in this process. Thirty participants with schizophrenia and acute delusional symptoms were compared with 29 healthy controls across three conditions involving a noise stressor, a social stressor or no stressor. Under each condition participants had to perform parallel versions of cognitive bias tasks and neuropsychological tests including a probabilistic reasoning task (jumping to conclusions), the revised Internal, Personal and Situational Attributions Questionnaire (IPSAQ-R; attributional style), and the Corsi block-tapping task (nonverbal memory). Stress, particularly noise, aggravated performance differences of patients relative to controls on memory. Participants with psychosis demonstrated an escalated jumping to conclusion bias under stress. At a medium effect size, patients made more monocausal attributions, which increased under social stress. The present study is partially in line with prior studies. It suggests that stress negatively affects cognition in psychosis more than in controls, which is presumably insufficiently realized by patients and thus not held in check by greater response hesitance. Raising patients' awareness about these response tendencies and encouraging them to be more cautious in their judgments under conditions of increased stress may prove beneficial for improving positive symptoms.