Attributional style in schizophrenia: an investigation in outpatients with and without persecutory delusions

The attributional style of outpatients with schizophrenia with and without persecutory delusions was investigated. Thirty individuals with schizophrenia were divided into persecutory-deluded and non-persecutory-deluded groups based on a score of 5 or higher on the suspiciousness item from the Expanded Brief Psychiatric Rating Scale (BPRS-E). The two resulting groups, and a nonclinical control group, were administered a battery of attributional measures, and their attributional responses were coded by both the subjects themselves and a pair of independent raters. The results showed evidence of a self-serving bias for subjects with persecutory delusions; however, this bias was not unique to those with persecutory delusions, and it disappeared when independent raters evaluated subjects' causal statements on a reliable measure of attributional style. Subjects with persecutory delusions tended to show a stronger bias toward blaming others rather than situations for negative outcomes, and there was a linear association between persecutory ideation and a self-serving attributional style. Finally, there were significant discrepancies between the attributional ratings of the persecutory-deluded subjects and those of independent judges. Implications for future research are discussed.