The BDI®-II is a tool designed to measure depression intensity in psychiatrically diagnosed patients. It may be helpful in detecting depressive episodes in accordance with diagnostic criteria used and in monitoring the patient's condition. It may also be applied in a research context.   

Reliability

Very high internal consistency – the Cronbach alpha  for the standardization sample was .91 (.93 in the case of depressive persons). High stability of examination scores – differences between the first and second administration were non-significant and the Pearson correlation between the test and retest was .86.

Validity

Two-factor structure of the inventory was found out (similar to the original version), although the factors themselves were different from those obtained in the American standardization study. The BDI®-II scores differentiate psychiatric patients diagnosed with depression from other psychiatric patients without depression diagnosis and those suffering from neurological damages and Huntington disease. The BDI®-II is a senstitive tool to detect changes in mood levels resulting from therapeutic intervention or development of a disease.

The BDI®-II should be used as a screening measure – it serves a purpose of preliminary assessment of the intensity of symptoms under examination. However, no definitive diagnosis of depression should be made based solely on its results.

Norms

The standardization sample included 574 non-patients aged 20–79. Examinations were carried out by 32 psychologists in all the 16 Polish voivodeships (administrative districts). Six age groups were taken into account while making the sample: 20–29, 30–39, 40–49, 50–59, 60–69 and 70–79 years, as well as socio-demographics such as gender, education level and place of residence.

Among the socio-demographics under control in the standardization sample age, education level and place of residence gave significant effects. In terms of age, the 70–79 group scored significantly higher than the other groups. In terms of education level, persons with at least high school edcuation scored significantly lower. In terms of place of residence big cities inhabitants had also scored significantly lower.     

The BDI®-II norms are defined on the two standard scales: s-ten and centile.

The test is also available as an online examination on the Epsilon Platform and as an option for entering and calculating scores from the paper-and-pencil version on the Epsilon Platform.