DSM-IV Criteria for Diagnosis of Depression

A. Five (of more) of the following symptoms have been present during the same 2-week period and represent a change from previous functioning; at least one of the symptoms is either depressed mood (1) or loss of interest or pleasure (2).

Note: Do not include symptoms that are clearly due to a general medical condition; or mood-incongruent delusions or hallucinations.

1. Depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feels sad or empty) or observation made by others (e.g., appears tearful). Note: In children and adolescents, can be irritable mood.

2. Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day (as indicated by either subjective account or observation made by others).

3. Significant weight loss when not dieting or weight gain (e.g., a change of more than 5% of body weight in a month), or decrease or increase in appetite nearly every day. Note: In children, consider failure to make expected weight gains.

4. Insomnia or hypersomnia nearly every day.

5. Psychomotor agitation or retardation nearly every day (observable by others, not merely subjective feelings of restlessness or being slowed down).

6. Fatigue or loss of energy nearly every day.

7. Feelings of worthlessness or excessive or inappropriate guilt (which may be delusional) nearly every day (not merely self-reproach or guilt about being sick).

8. Diminished ability to think or concentrate, or indecisiveness, nearly every day (either by subjective account or as observed by others).

9. Recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide.

B. The symptoms do not meet criteria for a Mixed Episode.

C. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.

D. The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition (e.g., hypothyroidism).

E. The symptoms are not better accounted for by Bereavement, i.e., after the loss of a loved one, the symptoms persist for longer than 2 months or are characterized by marked functional impairment, morbid preoccupation with worthlessness, suicidal ideation, psychotic symptoms, or psychomotor retardation.

Source: American Psychiatric Association (1994).

 

The Beck Depression Inventory (BDI a.k.a. "the Beck")

Sample item:

(Circle the number):

0 I do not feel sad.

1 I feel sad.

2 I am sad all the time and I can’t snap out of it.

3 I am so sad or unhappy that I can’t stand it.

Purpose

To assess the severity of depression in psychiatrically diagnosed adolescents and adults. Although the Beck was not designed to screen normals, it has been used extensively to do so.

Use

Interpretation only by professionals with appropriate clinical training and experience.

Administration and Scoring

Group or individual testing OK. May be administered orally (not like aspirin).

Scoring guidelines. Sum the ratings to each of the 21 items. Scores can range from 0 to 63. Item 19 is not scored if the person is trying to lose weight.

Interpretation

Score ranges are used to estimate the severity of depression. Specific item content (hopelessness and suicide) are also examined to assess risk and severity.

Psychometric Characteristics & Evaluation

Scale Development

The items in the first Beck were based on clinicians’ ideas of what depressed patients mentioned as symptoms plus symptoms frequently given by depressed patients but not non-depressed patients. Specific content is shown in the validity section.

Reliability

Six different samples were used to examine the scale characteristics and develop norms for interpreting scores. Item statistics for two of the samples are shown in Table 1.

 

 

Table 1. Item results for two groups of Beck respondents

 

Major Depressive

Disorder

Alcoholic

Item

Mean

SD

rtot

Mean

SD

rtot

Sadness

1.42

.85

.57

.60

.88

.63

Pessimism

1.30

.76

.54

.53

.90

.68

Failure

1.24

.91

.53

.91

1.01

.68

Dissatisfaction

1.55

.1

.59

.90

.886

.54

Guilt

1.12

.89

.41

.70

.86

.56

Punishment

.84

1.12

.35

.92

1.17

.51

Self-dislike

1.40

.78

.36

.75

.74

.60

Self-accusations

1.40

.78

.36

.73

.82

.51

Suicidal ideas

.83

.63

.48

.23

.58

.54

Crying

1.03

.95

.45

.71

1.08

.37

Irritability

1.07

.71

.43

.97

.98

.37

Social Withdrawal

1.12

.83

.56

.50

.74

.56

Indecisiveness

1.49

.89

.55

.70

.97

.69

Body image change

1.05

.92

.38

.50

.86

.57

Work difficulty

1.51

.71

.56

.74

.90

.57

Insomnia

1.10

.94

.29

.29

.98

.50

Fatigability

1.32

.83

.54

.69

.76

.35

Loss of Appetite

.65

.83

.37

.48

.74

.50

Weight Loss

.3

.72

.06

.33

.79

.38

Somatic Preoccupation

.60

.71

.32

.66

.76

.47

Loss of Libido

1.20

1.05

.49

.35

.75

.49

Total Score

23.56

9.24

 

13.88

10.60

 

Alpha

   

.86

   

.90

Major points to notice about Table 1:

1. Nearly all items have good corrected item total correlations.

2. The major depressive group scores higher than the depressed alcoholics.

3. The internal consistency is high for both groups.

Such results are consistent with other studies. One reported a meta-analysis of nine psychiatric samples, alpha = .86. Another reported a meta-analysis of .81 for 15 nonpsychiatric samples. The internal consistency, one estimate of reliability, of the Beck is good. Test-retest reliability is lower, as it should be (why?). For psychiatric samples, test retest estimates vary from .48 to .86. For nonpsychiatric samples, .60 to .90. Longer time frames are associated with lower estimates (why?).

Validity

Content Validity

Good original content match with definition of depression. No longer matches DSM exactly. Beck doesn’t ask about appetite gain or too much sleep, nor does it assess psychomotor agitation. The appetite and sleep items were left out intentionally because it was believed that most normals experience these things too often to be useful as indicators of depression.

Construct Validity

Convergent & Discriminant Validity. Correlations of the Beck with Hopelessness Scale (HS) and the Hamilton Psychiatric Rating Scale for Depression (HPSD) are shown in Table 2 (we expect to see large correlations). Also shown are correlations of the Beck with Sex and Age (where we expect to see small correlations).

Table 2. Correlations between the Beck and other Variables

Sample

HS

HPSD

Sex

Age

Mixed Diagnostic

(N=248)

.60

.66

.11

-.13

Major Depression (single ep) (N=113)

.38

.40

.04

-.09

Major Depression (recurrent) (N=168)

.68

.56

.06

-.01

Dysthymic Disorder (N=99)

.65

.56

.05

.03

Alcoholic

(N=105)

.76

.87

.16

-.07

Heroin-addicted

(N=211)

.46

.69

.17

-.11

Points to notice about Table 2. The correlations with the Beck and the HS and HPSD are large, although not so large as to indicate equivalence (assuming the HS and HPSD are as reliable as the Beck). This indicates reasonable convergence. The Beck does not appear correlated with Sex and Age, thus showing some evidence for discrminant validity. Stronger evidence for discriminant validity would be to show modest correlations with anxiety, neuroticism, or other clinical scales. Such evidence is not in the manual, and is likely to prove a problem for the Beck. The manual states that the Beck was not designed to discriminate among patients with different psychiatric diagnoses. I suspect it does not necessarily do a good job of this, and that means a real problem with using the Beck to screen people for depression. That is, a high score might mean something other than depression.

Known Groups. Several studies have shown that the Beck can discriminate psychiatric patients from normals.

Factor Analysis. Several different factor analysis techniques have been used to analyze the intercorrelations among the Beck items. The number and nature of the resulting factors depends upon the sample (patients, etc.) and type of factor analysis. According to the manual, the Beck can be characterized either by one global factor corresponding to depression, or to three highly correlated factors comprised of content concerning cognitive-affective problems, performance problems, and somatic complaints.