Good psychometric properties of the Birchwood Insight Scale for patients with bipolar disorder
Poster B16, Tuesday, October 9, 11:30 am - 1:00 pm, Essex Ballroom
Camilla Bakkalia Büchmann1, Geir Pedersen1, Sofie Ragnhild Aminoff1,2, Jannicke Fjæra Laskemoen1, Ingrid Melle1,2, Trine Vik Lagerberg2; 1University of Oslo, 2Oslo University Hospital
Birchwood Insight Scale (BIS) is a self-report questionnaire assessing patients’ awareness of illness, the ability to re-label unusual mental events as pathological and perceived need for treatment. Several studies have demonstrated its validity in patients with non-affective psychotic disorders, but validation studies in bipolar disorder (BD), where insight also could be compromised, is lacking. The aim of this study was to provide knowledge of the psychometric properties of BIS in a large BD sample. Secondary we aimed to investigate the concordance between BIS and single items assessing insight in the YMRS-C and the PANSS. We studied BIS in 998 participants, including a BD sample (BDI n = 282; BDII n = 138) and a reference sample comprising schizophrenia spectrum disorders (SCZ n = 577). We performed confirmatory factor analysis to examine the factorial structure of BIS in all three diagnostic groups. Bivariate correlational analysis was applied to examine the relationship between the different insight measures. Confirmatory factor analyses indicated a reasonable model fit to the original three-factor subscale structure of BIS in the BDI and BDII samples, in addition to the SCZ sample. The BIS full scale score and its subscales correlated signiﬁcantly with both the PANSS G12 and YMRS item 11 in both BDI and SCZ. In BDII, however, the BIS correlated poorly for all scales. Our study supports the use of BIS in BD populations. The study also demonstrates that patients’ self-reports of insight correspond to clinician-based single item ratings of insight in BDI and SCZ.
Topic Area: Mood Disorders