BDI-II (Beck Depression Inventory-II)

By Team TherapyRoute

The Beck Depression Inventory-II (BDI-II) is a self-report questionnaire that measures how severe a person's depression symptoms are. Self-report means the person answers about themselves, rather than being rated by an observer. The questions cover the past two weeks. A person completes it, and a qualified professional uses the result.^[1]

It measures severity. It is not a diagnosis, and it is not a self-test. The inventory is given and interpreted by a clinician, so this page explains it rather than offering it.

The inventory includes a question about thoughts of death. If you are feeling unsafe, please read this first.

Where the BDI-II comes from

The BDI-II did not start out under that name. It came out of the original Beck Depression Inventory, which Aaron Beck and colleagues developed.^[1]

Two revisions followed. The first, in 1978, produced the BDI-IA. The second, in 1996, produced the BDI-II.

The 1996 wording was matched to the DSM-IV description of a major depressive episode. The DSM-IV was a widely used diagnostic manual at that time, and the rewording made the inventory match the definition clinicians were then using. The Beck Depression Inventory has been used in more than 7,000 studies.^[1]

What it measures

The BDI-II has 21 items. They cover the main symptoms of depression, both psychological and physical (bodily). Each item is rated on a four-point scale, from 0 to 3.^[1][2]

The items also group into two underlying dimensions. Researchers who study the structure of the inventory call them cognitive-affective and somatic-vegetative.^[1]

• Cognitive-affective: the thinking and feeling side, covering mood and thoughts.
• Somatic-vegetative: the bodily side, covering symptoms such as sleep, appetite and energy.^[1]

The individual items are not listed on this page. Reproducing them would undermine the integrity of a professional clinical tool.

How it is scored and what the ranges mean

Scoring is simple arithmetic. The clinician adds up the ratings from every item, and that gives one total score for depression severity.^[1]

A higher total means more severe symptoms. Clinicians read the total against broad severity bands, which run from minimal symptoms at the low end up to severe symptoms at the high end.

The numeric scoring key is not published on this page. Cutoff scores are the boundaries between one band and the next, and the exact figures vary by setting and population. A clinician applies the cutoff that fits your situation.^[1]

A number on its own is not a diagnosis. It is one piece of information among several.

What your score does and does not tell you

You may have been given a number by a clinician. The score reflects how severe your symptoms have been recently. That is all it does. It is the starting point for a conversation, not the end of one.^[1]

A score does not, by itself, mean you have depression. Only a clinician can tell you what it means. They read it alongside everything else they know about you, and alongside what you tell them directly.

How clinicians use it

A clinician often gives the BDI-II at the start of treatment. That first score is the baseline. It is a fixed point that later scores can be measured against, which is how change over time becomes visible. The inventory may be repeated later to see whether symptoms have improved.

Because it can pick up change, the BDI-II is common in therapy research. In one trial of internet-based cognitive behavioural therapy, the BDI was measured before, during, and after treatment to track change. Cognitive therapy for depression is effective, in some cases equal or superior to medication alone.^[1][2][3]

Repeat testing is routine practice. It tracks the course of treatment rather than signalling that anything has gone wrong.

How well it works

The BDI-II is one of the most widely used measures of depression. A large review pooled 118 studies of the instrument. People tend to answer its items consistently.^[1]

Internal consistency describes how far the separate items measure the same thing. For the BDI-II it is reported at around 0.9. Scores are fairly stable when the inventory is repeated over short periods, and they agree well with other measures of depression.^[1]

In research, the inventory is checked against a separate diagnostic standard. It shows good sensitivity and good specificity for detecting depression. Sensitivity is how often it picks up people who do have depression; specificity is how often it correctly rules out those who do not. It identifies depression reasonably accurately.^[1]

What it cannot do

The BDI-II depends on honest self-report. Someone may over-report or under-report how they feel, whether deliberately or without realising it. And it only reflects the past two weeks, so a difficult fortnight can raise a score.^[1]

Some bodily symptoms can also come from physical illness rather than depression, and the inventory cannot tell the difference. It has been used across different languages and settings. Even so, the right cutoff still varies by setting.^[1]

The BDI-II is not designed to be used on its own. It is never the whole assessment. A clinician combines it with everything else the assessment shows.

Online 'BDI-II' tests, and getting a proper assessment

Free 'BDI-II' tests are widely available online. Many are unofficial copies, and some have been altered. A score from one of these is not a clinical assessment, and it should not be treated as one.

A valid BDI-II is given and interpreted by a qualified professional. Completing it asks you to read each statement and weigh it against your own experience, which takes a degree of reading ability and concentration. Whether it suits a particular person is a professional's judgement. That includes deciding whether it fits a younger person.

Depression is common. Effective support is available, and you can find the right therapist through TherapyRoute.

This article is for general information and is not a substitute for professional assessment or care. If this is affecting your life, consider reaching out to a qualified mental health professional.

References

1. [1] Wang, Y.-P., & Gorenstein, C. (2013). Psychometric properties of the Beck Depression Inventory-II: a comprehensive review. Revista Brasileira de Psiquiatria, 35(4), 416-431. doi.org/10.1590/1516-4446-2012-1048.
2. [2] National Center for Biotechnology Information. Internet-based cognitive behavioural therapy trial using the BDI-II as an outcome measure. pmc.ncbi.nlm.nih.gov/articles/PMC6096244.
3. [3] Kaplan & Sadock's Comprehensive Textbook of Psychiatry (10th ed., 2017). Wolters Kluwer.