Purpose: Designed to measure presence of depression.
Population: Adolescents and adults.
Score: Produces single score indicating intensity of the depressive episode.
Time: Not reported.
Author: Aaron T. Beck.
Publisher: Center for Cognitive Therapy.
Description: The Beck Depression Inventory (BDI) is a 21-item test presented in multiple choice format which purports to measure presence and degree of depression in adolescents and adults. Each of the 21-items of the BDI attempts to assess a specific symptom or attitude "which appear(s) to be specific to depressed patients, and which are consistent with descriptions of the depression contained in the psychiatric literature." Although the author, Aaron T. Beck, is associated with the development of the cognitive theory of depression, the Beck Depression Inventory was designed to assess depression independent of any particular theoretical bias.
Scoring: Each of the inventory items corresponds to a specific category of depressive symptom and/or attitude. Each category purports to describe a specific behavioral manifestation of depression and consists of a graded series of four self-evaluative statements. The statements are rank ordered and weighted to reflect the range of severity of the symptom from neutral to maximum severity. Numerical Values of zero, one, two, or three are assigned each statement to indicate degree of severity. Beck admits that there is no arbitrary cutoff score and the specific cutoff depends on the characteristics of the patients used and the purpose for which the inventory is given.
Reliability: Test-retest reliability has been studied in the case of 38 patients who were given the BDI on two occasions. It was discovered that the changes in BDI scores tended to parallel changes in the clinical reading of the depth of depression, indicating a consistent relationship between BDI scores and the patientís clinical state. The reliability figures here were above .90. Internal consistency studies demonstrated a correlation coefficient of .86 for the test items, and the Spearman-Brown correlation for the reliability of the BDI yielded a coefficient of .93.
Validity: In assessing the validity of the BDI, the readily apparent face validity of the BDI must be addressed. The BDI looks as though it is assessing depression. While this may be quite advantageous, it may make it easy for a subject to distort the results of the test. Content validity would seem to be quite high since the BDI appears to evaluate well a wide variety of symptoms and attitudes associated with depression. One study addressing concurrent validity demonstrated a correlation of .77 between the inventory and psychiatric rating using university students as subjects. Beck reports similar studies in which coefficients of .65 and .67 were obtained in comparing results of the BDI with psychiatric ratings of patients.
Norms: Normative sample included 226 psychiatric in- and out-patients.
Suggested Uses: The BDI is recommended in research and clinical settings.