Beck Depression Inventory

The Beck Depression Inventory (BDI, BDI-II), created by Dr. Aaron T. Beck, is a 21-question multiple choice survey that is one of the most widely used instruments for measuring the severity of depression. The questionnaire is composed of items relating to depression symptoms such as hopelessness and irritability, cognitions such as guilt or feelings of being punished, as well as physical symptoms such as fatigue, weight loss, and lack of interest in sex. There are two versions of the BDI -- the original BDI, first published in 1961 and later revised in 1971; and the BDI-II, a revision of the BDI that was published in 1996.

BDI
The original BDI, first published in 1961 and later revised in 1971, consists of 21 questions about how the subject was feeling in the last week. Each set of four possible answer choices range in increasing intensity. When the test is scored, a value of 0 to 3 is assigned for each answer and then the total score is compared to a key to determine the depression's severity. The standard cut-offs are as follows: 0-9 indicates that a person is not depressed, 10-18 indicates mild-moderate depression, 19-29 indicates moderate-severe depression and 30-63 signifies indicates severe depression. Higher total scores indicate more severe depressive symptoms.

BDI-II
The BDI-II was a 1996 revision of the BDI, created to fall in line with the updated DSM-IV criteria for depression. Items involving changes in body image, somatic preoccupation, and work difficulty were replaced. Also, sleep loss and appetite loss items were revised to assess both increases and decreases in sleep and appetite. Finally, participants are asked to rate how they have been feeling for the past two weeks, as opposed to the past week as in the original BDI.

Like the BDI, the BDI-II also contains 21 questions, each answer being scored on a scale value of 0 to 3. The cutoffs used differ from the original: 0-13 - minimal depression; 14-19 - mild depression; 20-28 -moderate depression; and 29-63 - severe depression. Higher total scores indicate more severe depressive symptoms. Internal consistency is good, with a Cronbach's alpha coefficient of around 0.85 (e.g. Ambrosini et al. 1991).

Limitations of the BDI
In participants with concomitant physical illness, it has been suggested (e.g. Moore et al. 1998) that its reliance on physical symptoms such as fatigue might artificially inflate scores due to symptoms of the illness, rather than of depression. Because of this, researchers and clinicians who work with medically ill populations might consider using the Center for Epidemiologic Studies - Depression Scale (CES-D) or the Hospital Anxiety and Depression Scale (HADS) as alternative measures.