Personal Beliefs about Illness Questionnaire-Revised (PBIQ-R): Spanish adaptation in a clinical sample with psychotic disorders.

Background: The way people with psychosis psychologically adapt and manage the diagnosis of such a mental disorder has been considered a key factor that contributes to the emergence and aggravation of emotional problems. These beliefs about illness can be very important due to their possible association with stigma and its implications in terms of loss of roles and social status. Given the importance of these personal beliefs about the specific diagnosis of psychosis, the Personal Beliefs about Illness Questionnaire (PBIQ) and PBIQ-R have been developed.

Aims: The present study aims to explore the psychometric characteristics of the Spanish version of the PBIQ-R in a sample of patients with a diagnosis of psychosis-related disorders.

Method: Participants were 155 patients (54.8% male) of the Public Health Service in Andalusia (Spain). Those who consented to participate filled in the PBIQ-R, the Social Comparison Scale, and the PHQ-9 and GAD-7 to measure emotional symptoms.

Results: All dimensions showed adequate internal consistency values: Cronbach's alpha extends between .81 and .88; and McDonald's omega ranges between .87 and .92. The temporal reliability for an interval of 3-4 weeks was high. The correlations between the PBIQ-R dimensions and the other variables included in the study were significant and in the expected direction. The factor analysis of the principal components of the PBIQ-R dimensions revealed a single factor in each of the dimensions that explained 64-74%.

Conclusions: The results support the reliability and validity of the Spanish version of the PBIQ-R.