Beck Depression Inventory (BDI-II)

The Beck Depression Inventory is a 21-item self-report questionnaire that measures the severity of depressive symptoms over the preceding two weeks. Each item is scored from 0 to 3, giving a total from 0 to 63. The most recent version is the second edition.

It measures severity rather than diagnosis, and it is used in both clinical and research settings to track symptoms over time.

Usage. It is used in specialist mental health services, psychology services, and to monitor response to treatment.

Indications. Assessment of depression severity, monitoring of response, and clinical research.

Preparation and technique. The patient completes the inventory in private, and the clinician reviews the responses, particularly the question on suicidal thoughts.

Contraindications and precautions. Reliability is limited in people with limited literacy or cognitive impairment. Medical illness and its treatment can inflate somatic items.

Interpretation.

• Scores of 0 to 13 indicate minimal depression.
• Scores of 14 to 19 indicate mild depression.
• Scores of 20 to 28 indicate moderate depression.
• Scores of 29 to 63 indicate severe depression.

Causes of a raised score. Depressive disorder, bipolar disorder, medical illness, medication effects, and substance use.

Critical values and findings needing immediate action.

• A positive response to the suicide question, indicating thoughts of suicide, requires a same day risk assessment by a clinician.
• A severe score with functional collapse or psychotic features requires urgent specialist review.

Limitations and artefacts. The inventory measures symptoms and is not a diagnostic tool. Somatic items overlap with medical illness, which can overstate severity. Reading level and cultural expression of mood affect responses.

Follow up tests. A structured clinical interview to confirm the diagnosis, thyroid function tests, and full blood count where a medical cause is possible.

Special groups. Older adults may under report symptoms, and the inventory is used with a geriatric depression measure where available. Adolescents may need an adapted interpretation.