Abstract
The functioning of a Finnish modification of the 13-item Beck Depression Inventory (R-BDI) in measuring the mood of an adolescent population was studied in a large population sample of 14- to 16-year-old adolescents (n =17,643) who participated in the 1997 School Health Study. Adolescents were well able to answer the items of the R-BDI. Dropout due to incomplete scale response was 6.7%. Of the individual items, girls had omitted 2.5%-3.7%, and boys 4.1%-4.9%. Factor analyses yielded a two-factor solution for both sexes. The factors were psychologically meaningful. The internal consistency of the scale was good. Cronbach's alpha was 0.84 for girls and 0.87 for boys. In the R-BDI the original 13-item BDI is supplemented with a positive-mood scale. The positive-mood scale appeared functional and meaningful in factor analysis and reliability test.