Personalizing and externalizing biases in deluded and depressed patients: are attributional biases a stable and specific characteristic of delusions?

OBJECTIVES The purpose of this study was to explore whether explicit and implicit attributional styles of delusional patients were associated to their clinical state, and whether attributions biases are specific to delusional psychopathology or also appear in other disorders (i.e. depression). DESIGN AND METHODS A cross-sectional design was used. The sample consisted of 136 participants (40 acute deluded participants, 25 remitted deluded participants, 35 depressed patients and 36 normal controls). The Internal, Personal and Situational Attributions Questionnaire (IPSAQ) and the Pragmatic Inferential Test (PIT) were used to assess explicit and implicit attributional style, respectively. RESULTS All participants, with the exception of the depressed patients group, showed an externalizing bias (EB) for negative events. Although both acute and remitted deluded patients showed a similar overall pattern of explicit attributions, the personalizing bias (PB) was significantly greater in the acute group. The magnitude of this bias, which was also found in the depressed patients, was significantly related to the patient's degree of severity, as assessed by the total BPRS score (r=.45, p<.001). The results on the implicit attributions were more equivocal, perhaps due the low reliability of the PIT. CONCLUSIONS Attributional biases seem to be a stable characteristic of delusions. Yet, the PB might be a rather unspecific characteristic that varies with the degree of the severity of psychopathology. The implications of these findings for understanding the role of attributional biases in depression and delusion formation are discussed.