Screening Tests for Depression

The estimated prevalence of depressive disorders is 13–22% in primary care clinics but is only recognized in approximately 50% of cases. ^{[1, 2]} The US Preventative Services Task Force (USPSTF) recommendations were updated in 2016. The USPSTF published a level B recommendation for screening for depression in the general adult population (18 years and older), including older patients and pregnant and postpartum women. Screening should be implemented with adequate systems in place to ensure accurate diagnosis, effective treatment, and appropriate follow-up. ^[3]

Use of patient-administered screening tools has increased as a quick and reliable option in the first step of depression assessment or as a treatment monitor. ^[4] An initial screen must be followed by a clinical interview to make the diagnosis of depression. The Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for major depression are reviewed below. ^[5]

Diagnostic criteria for major depressive disorder (DSM-5)

At least 5 of the following symptoms have been present during the same 2-week period, represent a change from previous functioning, and include either depressed mood or loss of interest or pleasure.

• Depressed mood

• Marked diminished interest or pleasure

• Significant weight loss or weight gain

• Insomnia or hypersomnia

• Psychomotor agitation or retardation

• Fatigue or loss of energy

• Feelings of worthlessness or excessive guilt

• Diminished ability to concentrate

• Recurrent thoughts of death or suicidal ideation

A 2002 literature review found that median sensitivity across 16 instruments, including the BDI, CES-D, SDS, and GDS, for major depression was 85%, ranging from 50% to 97%, while median specificity was 74%, ranging from 51% to 98%. ^[6] The more common screening tools will be reviewed in this topic, including the following:

• Hamilton Depression Rating Scale (HDRS)

• Beck Depression Inventory (BDI)

• Patient Health Questionnaire (PHQ)

• Major Depression Inventory (MDI)

• Center for Epidemiologic Studies Depression Scale (CES-D)

• Zung Self-Rating Depression Scale (SDS)

• Geriatric Depression Scale (GDS)

• Cornell Scale for Depression in Dementia (CSDD)

The Hamilton Depression Rating Scale is the most widely used interview scale, developed in 1960 to measure severity of depression in an inpatient population. Since then, many versions have been adapted, including structured interview guides, self-report forms, and computerized versions.

In the original clinician-administered scale, the first 17 items are tallied for the total score, while items 18–21 are used to further qualify the depression. The scale takes 20–30 minutes to administer. Scores of 0–7 are considered normal, and scores greater than or equal to 20 indicate moderately severe depression. Each item either is scored on a 5-point scale, representing absent, mild, moderate, or severe symptoms, or on a 3-point scale, representing absent, slight or doubtful, and clearly present symptoms. The HDRS contains a relatively large number of somatic symptoms and relatively few cognitive or affective symptoms. ^{[7, 8, 9]} The 21 items it assesses are as follows:

• Depressed mood

• Feelings of guilt

• Thoughts of suicide

• Insomnia

• Work and activities

• Psychomotor retardation

• Psychomotor agitation

• Psychic anxiety

• Somatic anxiety

• Gastrointestinal symptoms

• General somatic symptoms

• Genital symptoms

• Hypochondriasis

• Loss of insight

• Loss of weight

• Diurnal variation

• Depersonalization and derealization

• Paranoid symptoms

• Obsessional and compulsive symptoms

See the image below.

Hamilton Depression Rating Scale. (PDF)

The Beck Depression Inventory (BDI) is the most widely used self-rating scale, developed in 1961 by Aaron Beck based on symptoms he observed to be common among depressed patients.

The BDI consists of 21 items of emotional, behavioral, and somatic symptoms that takes 5–10 minutes to administer. The items are scored from 0 to 3 and measure mood, pessimism, sense of failure, lack of satisfaction, guilty feelings, sense of punishment, self hate, self accusations, self-punitive wishes, crying spells, irritability, social withdrawal, indecisiveness, body image, work inhibition, sleep disturbance, fatigability, loss of appetite, weight loss, somatic preoccupation, and loss of libido.

Scores of 10-18 indicate mild depression, 19–29 indicate moderate depression, and greater than 30 indicate severe depression. ^[10] Other versions have been developed, including the Beck Depression Inventory II (BDI-II), a revision of the BDI in 1996 in response to the fourth edition of the DSM, and the Beck Depression Inventory for Primary Care (BDI-PC). The BDI-II is scored in the same manner as the BDI, but the cutoffs differ slightly. The BDI-PC is a screening 7-item scale for primary care outpatients, with a cut-off of 4 points for major depression. One study found a 97% sensitivity and 99% specificity rate for identifying patients with major depression. ^[11] (The BDI is copyright protected and cannot be reproduced here. It can be purchased from Psychcorp.com.)

The Patient Health Questionnaire is a self-administered tool of 2 (PHQ2) or 9 (PHQ9) items. A meta-analysis found sensitivity to be 80% and specificity of 92%. The PHQ2 is a screening tool for depression that assesses the frequency of depressed mood and anhedonia over the past 2 weeks, scoring each as 0 ("not at all") to 3 ("nearly every day").

A PHQ-2 score of greater than 3 had a sensitivity of 83% and a specificity of 92% for major depression. ^{[5, 12]} The PHQ 9 establishes the clinical diagnosis of depression and can additionally be used over time to track the severity of symptoms over time. The cut point of the PHQ9 is equal or greater than 10, which has a sensitivity of 88% and a specificity of 88% for major depression. PHQ-9 scores of 5, 10, 15, and 20 are representative of mild, moderate, moderately severe, and severe depression, respectively (see the image below). ^{[4, 6]}

Patient Health Questionnaire (PHQ-9). (PDF)

The Major Depression Inventory (MDI) is a self-rating scale used for the diagnosis or measurement of depression, according to both DSM-IV major depression and ICD-10 moderate to severe depression criteria. The symptoms should have been present nearly every day during the past 2 weeks. In both the DSM-IV and ICD-10, the items of depressed mood and lack of interest are considered as the core symptoms of depression.

For the diagnosis of major depression, either item 1 or 2 should be among the 5 of 9 items present. Items 4 and 5 are combined, with only the highest answer category is considered and a total number of items of nine. As a diagnostic tool, the 10 items are dichotomized for the presence (1) or absence (0) of each symptom. As a measuring tool, the items are given a value (0-5) and summed up to a theoretical score of 0 to 50. The cutoff score is 26 for the diagnosis of major (moderate to severe) depression. The sensitivity of the MDI algorithms is between 86% and 92%, while the specificity is between 82% and 86% (see the image below). ^[13]

Major Depression Inventory. (PDF)

The Center for Epidemiologic Studies Depression (CES-D) scale was published in 1977 as a screening tool for depression in the general population. The CES-D is often used in studies examining the well-being of participants in large-scale population surveys. The self-administered screening scale consists of 20 items, 16 negatively worded and 4 positively worded. The instrument measures affective and somatic aspects of depression. ^{[9, 14]} Each question receives a score ranging from 0 to 3, and the possible range of scores is from 0 to 60, with higher scores indicating the presence of greater symptomatology. The CES-D was revised to reflect current DSM-IV diagnostic criteria for depression, the CESD-R (see the image below). ^[15]

Center for Epidemiologic Studies Depression Scale. (PDF)

The Zung Self-Rated Depression Scale (SDS), originally called the Self-Rating Depression Scale, is a 20-item self-administered test published in 1965 with the goal of developing a quick and inclusive self-administered tool. Half of the 20 items are positively worded and half are negatively worded. This scale has been used in clinical research to monitor treatment or as a screening tool in general practice. The SDS has a key for scoring, with scores ranging from 1 to 4. Scores greater than 50 indicate mild depression, greater than 60 indicate moderate depression, and greater than 70 indicate severe depression (see the image below). ^{[9, 16]}

Zung Self-Rated Depression Scale. (PDF)

The Geriatric Depression Scale (GDS) was specifically developed for use in geriatric populations, originally as a 30-item scale. It was modified a 15-item scale, which has been widely used. The GDS was later reduced to 5 items, so as to be better received by elderly patients. The questions elicit only “yes” or “no” responses, making comprehension easier compared with multiple-choice answers.

The 5-item scale has a sensitivity of 94%, specificity of 81%, and demonstrated a significant agreement in the clinical diagnosis of depression with the 15-item scale. The 5-item scale is scored by 1 point for a “no” answer on the first question or a “yes” answer for the remaining questions. A score of greater than or equal to 2 is a positive screen for depression (see the images below). ^[17]

Geriatric Depression Scale. (PDF)

Geriatric Depression Scale-Short. (PDF)

The Cornell Scale for Depression in Dementia (CSDD) is designed for use in elderly patients with underlying cognitive deficits. Because this patient population may give unreliable answers, the CSDD additionally uses information from a patient informant, someone who knows and has frequent contact with the patient, and can include family members or care staff.

The CSDD takes approximately 20 minutes to administer. The CSDD is a 19-item scale, with scores of 0 for absent, 1 for mild or intermittent, and 2 for severe symptoms. A total score of 10 indicate probable major depression and greater than 18 indicate definite major depression. However, a recent study found a score of 6 or more has a sensitivity of 93% and specificity of 97%. The same questions are asked of both the patient and the informant and include mood-related signs of anxiety, sadness, lack of reactivity to pleasant events, and irritability; behavioral disturbance including psychomotor agitation and retardation, physical complaints, acute loss of interest; physical signs such as appetite loss, weight loss, and lack of energy; cyclic functions including diurnal variations and sleep difficulties; and ideation disturbance including suicide, self-deprecation, pessimism, and mood congruent delusions (see the image below). ^{[18, 19, 20]}

Cornell Scale for Depression in Dementia. (PDF)

Depression is a major public health issue, causing significant suffering and disability in the United States and worldwide. Most potential patients are first seen in primary care settings where depth mental status evaluation is not routine. The use of depression screening instruments can be a simple, efficient method to provide such screening in a sensitive and specific manner.

The Beck Depression Inventory, Patient Health Questionnaire, Major Depression Inventory, and Zung Self-Rating Depression Scale are all self-administered and highly suitable for primary care settings. These scales, as well as the clinician-administered CES-D, Hamilton Depression Rating Scale, Geriatric Depression Scale, and Cornell Scale for Depression in Dementia have been widely validated.