Persecutory delusions and attributional style.
Seventeen psychotic patients with persecutory delusions were matched against depressed and normal controls and assessed for magical ideation, locus of control and attributional style. The deluded and depressed patients were found to make global and stable attributions when compared to the normal subjects. However, the deluded patients, in contrast with both control groups, made excessively external attributions for negative events and internal attributions for positive events. Highly significant differences were observed between the deluded group and the two control groups on magical ideation and on the 'powerful others' subscale of the locus of control questionnaire. Both psychiatric groups differed from the normal control group on 'chance' locus of control and a significant difference was observed between the persecuted and normal subjects on the 'internality' subscale of the questionnaire. The implications of these findings for the understanding and treatment of paranoid delusions are discussed.