Do Antipsychotics Improve Reasoning Biases? A Review

Objective: To explore how reasoning biases in schizophrenic patients respond to treatment. Patients with schizophrenia, especially those with delusions, show not only cognitive deficits but also “reasoning biases,” namely, “jumping to conclusions,” reduced belief flexibility, an externalizing attributional style, and an impaired “theory of mind.” Methods: This is a systematic review of 17 longitudinal and cross-sectional studies. Results: “Jumping to conclusions” and reduced “belief flexibility” are most closely related to the severity of delusions, whereas “theory of mind” is better related to negative symptoms and “attributional style” to overall psychopathology. Antipsychotic treatment leads to an improvement in belief flexibility and theory of mind, with the suggestion that “belief flexibility” may be mediating the treatment response. On the other hand, the “jumping to conclusions” bias is likely a stable “trait” factor, which does not change with treatment, although it may moderate the outcome of response. The findings above are offered with the caveat that most of the available studies are small, often uncontrolled, few are longitudinal, that the measurement of some of the reasoning measures varies across studies, and that their relationship to the more established “cognitive” deficits remains unclear. Conclusions: The fact that these reasoning biases could be moderators and mediators of treatment outcome provides a greater impetus to study them systematically. IPSAQ = Internal, Personal and Situational Attributions Questionnaire; JTC = jumping to conclusions; PANSS = Positive and Negative Syndrome Scale; PIT = Pragmatic Inference Task; ToM = theory of mind.