The WBI-AB4 scale included question A and four
items quoted from WHO-CIDI 3.0. The scoring algorithm calculated
the number of symptom items scored “yes” (ranging from
0 to 9). The diagnostic criteria for bipolar type I or II according to
the ICD-10 do not include the duration of symptoms and severity
K. Imamura et al. / Journal of Affective Disorders 178 (2015) 32–38 33
of impairment. For the above reason, the present study did not use
the items of the duration of symptoms (the last item in the
question A) and severity of impairment (question C)