Personal beliefs about illness questionnaire-revised (PBIQ-R): reliability and validation in a first episode sample.

OBJECTIVE: To further develop the Personal Beliefs about Illness Questionnaire (PBIQ), which reflects current constructs of social rank theory in relation to people experiencing psychosis.
METHOD: Drawing on extensive clinical and research experience and after consultation with other mental health professionals and service users, 17 new items were added to 12 from the original 16 PBIQ questions. These made up five theoretical constructs (entrapment, loss, social marginalization, shame, and control). A total of 150 people who had just experienced a first episode of psychosis completed the newly devised PBIQ-R. To test the validity of its five subscales, a small sub-sample (N= 66) for whom follow-up data was available also completed measures of depression, insight, and other social rank appraisals.
RESULTS: All five subscales of the PBIQ-R were found to be reliable, valid, and sensitive to change.
CONCLUSIONS: Although the PBIQ-R was not designed to produce an overall 'personal beliefs about illness' score, its five subscales provide a rapid and valid method to assess and measure common psychological reactions to a first episode of psychosis. It will have relevance for use in older, multiple episode samples although further validation may be needed. ©2012 The British Psychological Society.