The Beck Depression Inventory - Second Edition (BDI-II; Beck, Steer & Brown, 1996) constitutes a culmination of 35 years of psychometric data and clinical experience with the BDI and BDI-IA to provide an instument for measuring the severity of depression in those aged 13 and above. The inventory's author, Aaron T. Beck, has been a key figure in the development of psychological theories for depressive mood disorders, surmising that a clients thought processes are causative factors in depression (Beck, 1967, 1987). Negative schemata, coupled with cognitive biases or distortions, maintain what Beck referred to as the negative triad: negative interpretations and views of the self, the world and the future. Despite Beck's theoretical investigations of depression, the original BDI was based on the descriptive statements regarding symptoms reported by depressed psychiatric patients and more infrequently by nondepressed psychiatric patients (Beck, Ward, Mendelson, Mock & Erbaugh, 1961). These verbal descriptions were not chosen to reflect any particular theory of depression. In 1971, Beck and his associates at the Philadelphia Center for Cognitive Therapy at the University of Pennsylvania began to develop what would become the amended version of the original BDI. The BDI-IA (copyrighted 1978, published 1979) involved the rewording of some items and an elimination of what were perceived to be double negatives. The number of optional responses were also limited to four, including the null (0) option. The second edition was developed in order to more accurately reflect criteria in the Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition (DSM-IV; 1994) for the diagnosis of depressive disorders. The BDI-II therefore presents a substantial revision of the original BDI's content, which was criticised due to its apparent lack of satisfactory applicability to the nine criteria set out for depression in the DSM-III (Moran & Lambert, 1983; Vredenburg, Krames and Flett, 1985). The appearance of the DSM-III-R (1987) and DSM-IV (1994) only underscored the need for an updated version of the BDI which would be more effectively applied in clinical practice. As a result, the BDI-II has less of an apparent focus on the somatic components of depression, as witnessed in outpatients. Symptoms such as Body Image Change, Weight Loss and Somatic Preoccupation were dropped in favour of symptoms which were not only more useful in assessing the severity of depression, but were in accordance with DSM-IV criteria for assessment, such as Agitation, Worthlessness, Concentration Difficulty and Loss of Energy. It was also felt that the dropped somatic items, as well as Work Difficulty, may have contributed to the generation of false positives as many people may experience fluctuations within these symptoms from time to time within the course of their lives but were not necessarily depressed (Steer & Beck, 1985). However, the choice not to include these items does not mean somatic symptoms are no longer addressed in the BDI-II, just to a lesser degree. The BDI-II now consists of the following 21 items: (1) Sadness, (2) Pessimism, (3) Past Failure, (4) Loss of Pleasure, (5) Guilty Feelings, (6) Punishment, (7) Self-Dislike, (8) Self-Criticalness, (9) Suicidal Thoughts or Wishes, (10) Crying, (11) Agitation, (12) Loss of Interest, (13) Indecisiveness, (14) Worthlessness, (15) Loss of Energy, (16) Changes in Sleeping Pattern, (17) Irritability, (18) Changes in Appetite, (19) Concentration Difficulty, (20) Tiredness or Fatigue, and (21) Loss of Interest in Sex.

Measures of the BDI-II's reliability and validity were obtained from a sample of 500 outpatients from various suburban and urban locations, as well as a comparitive sample of 120 first year psychology students from the University of New Brunswick in Fredericton, Canada. Results of both these reliability and validity measures are reported in the BDI-II Manual and prove to be most encouraging. An analysis of internal consistency for the outpatients revealed a coefficient alpha of .92, and for the college students .93, both coefficients being higher than those obtained for the BDI-IA. Similarly the test-retest reliability correlation of .93 (p<.001) and item-option characteristic curves also reveal an impressive overall reliability for the BDI-II.

Due to the development of the BDI-II in accordance with depressive symptoms listed in the DSM-IV, the inventory's content validity is therefore especially pertinent to the diagnosis of depressive disorders within clinical practice. It is therefore encouraging to find that the original BDI had high convergent validity with psychiatric ratings for the severity of depression amongst clientele (Beck et al., 1961; Bumberry, Oliver & McClure, 1978). Tests of concurrent validity have also consistently provided promising results, particularly in practical settings such as outpatient facilities (Ambrosini, Metz, Bianchi, Rabinovich & Undie, 1991).

Finally, while the BDI-II has an elementary degree of face validity, most likely due to the methods involved in its development, the relative simplicity and overt nature of the test constitutes its greatest weakness - the generation of false positives and/or the potential for insincere responses/item choices. Further redevelopment of the BDI may do well to address the fixed-order of statement presentation and provide a more randomized inventory to prevent overendorsement of extreme options (Dahlstrom, Brooks and Peterson, 1990) and effects such as the one identified by Hatzenbuehler, Parpal and Mathews (1983) in which repeated subsequent administration yielded lower scores. While the latter effect may be indicating practise or memory effects, the inventory's simplicity lends creedence to the supposition that initial scores may well be too high and that clients are more 'honest' in further attempts.

Since the development of the original BDI by Beck et al. (1961) the instrument has been one of the most popular assessment tools for not only detecting the possibility of depression but gauging its severity amongst those who have previously been diagnosed (Archer, Maruish, Imhof & Piotrowski, 1991; Piotrowski & Keller, 1992; Piotrowski, Sherry & Keller, 1985). One of the strengths which would lead to the popularity of the BDI-II (and its predecessors) is the relative ease of administration and scoring. The items can either take the form of a self-report inventory or be read aloud by an examiner, a feature which would be beneficial in circumstances in which the respondent could not read or write. The inventory takes only 5 to 10 minutes to complete, comparable to the BDI-IA (Ball, Archer & Imhof, 1994), as the client endorses one statement for each of the 21 items. The BDI-II Manual also states an interesting point in reporting that those with severe depression or obsessional disorders will often take longer to complete the test.

The BDI-II's main competition for the detection and assessment of depression would appear to be the Center for Epidemiologic Studies Depression Scale (CES-D), IPAT Depression Scale (Personality Assessment Inventory), Hamilton Rating Scale for Depression (RHRSD - Revised), Depression Anxiety Stress Scales (DASS), Multiscore Depression Inventory and the Zung Depression Scale. While the BDI appears to perform better as a screening instrument than tests such as the CES-D (Roberts, Lewinsohn & Seeley, 1991), the recommendation seems to be that no instrument be used on its own as a determinant for diagnosis. This conclusion is particularly significant when dealing with tests which have a tendency to generate a number of false positives. (Roberts et al., 1991). While the suspected presence of depression, particularly suicidal thoughts or wishes, warrants further attention and careful monitoring of the client in question, this attention would be more wisely invested towards further investigation before a final diagnosis is made. Even the BDI-II Manual acknowledges that attention be given to the "overall pattern of depressive symptoms" so as to address each patients individual and "distinctive depressive syndrome" (Beck, Steer & Brown, 1996).

It should also be noted that the BDI-II is a significantly sensitive instrument, having different cut scores than those of its predecessors for identifying the clients position in a range of four groups. While attempting to avoid false negatives, it works to the detriment of the inventory in providing a greater chance that nondepressed individuals may be falsely diagnosed. While Beck et al. (1996) suggests in the Manual that the range be altered as required to address sensitivity for research purposes, it would seem logical (if not ethical!) that this need to scrutinize the instruments sensitivity ould also be evident within the clinical setting. The justification for altering the range seems to be in order to prevent the possibility that those who are clinically depressed may 'slip through the cracks' and their condition not be given an accurate indication of severity. However, it would appear that the BDI is prone to errors in the opposite direction, generating false positives rather than false negatives, and that an increase in the instruments sensitivity would actually jeopardize BDI-II assessment. A false or excesively severe diagnosis of depression could also have significant effects not only upon a clients course of treatment, but upon lifestyle.

Research using the BDI-II specifically is at this point in time noticeably sparse, although it seems that the instrument will capitalise on the original BDI's (and BDI-IA's) popularity in respect to its application within clinical settings and research. While research pertinent to the latest version of the inventory will undoubtedly appear in later years, at this stage it seems that despite the changes to the original that constitute the BDI-II, it still remains one of the most efficient instruments available to the modern psychologist.

References

Ambrosini, P. J., Metz, C., Bianchi, M. D., Rabinovich, H., & Undie, A. (1991). Concurrent validity and psychometric properties of the Beck Depression Inventory in outpatient adolescents. Journal of the American Academy of Child and Adolescent Psychiatry, 30 (1), 51-57.
Archer, R. P., Maruish, M., Imhof, E. A., & Piotrowski, C. (1991). Psychological test usage with adolescent clients: 1990 survey findings. Professional Psychology, Research and Practice, 22 (3), 247-252.
Ball, J. D., Archer, R. P., & Imhof, E. A. (1994). Time requirements of psychological testing: A survey of practitioners. Journal of Personality Assessment, 63 (2), 239-249.
Beck, A. T. (1967). Depression: Clinical, experimental and theoretical aspects. New York: Harper & Row.
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Bumberry, W., Oliver, J. M., & McClure, J. N. (1978). Validation of the Beck Depression Inventory in a university population using psychiatric estimate as criterion. Journal of Consulting and Clinical Psychology, 46, 150-155.
Dahlstrom, W. G., Brooks, J. D., & Peterson, C. D. (1990). The Beck Depression Inventory: Item order and the impact of response sets. Journal of Personality Assessment, 55 (1&2), 224-233.
Hatzenbuehler, L. C., Parpal, M., & Mathews, L. (1983). Classifying college students as depressed or nondepressed using the Beck Depression Inventory: An empirical analysis. Journal of Consulting and Clinical Psychology, 51, 360-366.
Piotrowski, C., & Keller, J. W. (1992). Psychological testing in applied settings: A literature review from 1982-1992. Journal of Training & Practice in Professional Psychology, 6 (2), 74-82.
Piotrowski, C., Sherry, D., & Keller, J. W. (1985). Psychodiagnostic test usage: A survey of the Society for Personality Assessment. Journal of Personality Assessment, 49, 115-119.
Roberts, R. E., Lewinsohn, P. M., & Seeley, J. R. (1991). Screening for adolescent depression: a comparison of depression scales. Journal of the American Academy of Child and Adolescent Psychiatry, 30 (1), 58-59.
Steer, R. A., & Beck, A. T. (1985). Modifying the Beck Depression Inventory: A reply to Vredenburg, Krames, and Flett. Psychological Reports, 57, 625-626.