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PHQ-9 questionnaire

Screens depressive episodes and measures symptoms over the last 2 weeks. A screening instrument, not a diagnosis.

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Check the population, units and version. The result shows the formula or classification; it does not make an automatic treatment decision.

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Method · Limits of application

PHQ-9/Kroenke 2001: 9 items 0–3, total 0–27; original cutoff 10 versus Brazilian Santos 2013≥9; item 9 alert

Screening and symptom severity over the past two weeks; it does not replace a diagnostic interview. Distinguish the original ≥10 cutoff from the ≥9 cutoff studied in the adult Pelotas population. Published sensitivity and specificity values do not automatically validate other populations or translations.

Required fields: 0/9 completed

Complete all required fields. Optional fields are marked.

Over the last 2 weeks, how often have you been bothered by… 1. Little interest or pleasure in doing things required

2. Feeling down, depressed or without hope required

3. Trouble falling or staying asleep, or sleeping more than usual required

4. Feeling tired or having little energy required

5. Poor appetite or overeating required

6. Feeling bad about yourself — or feeling you are a failure or have let yourself or your family down required

7. Trouble concentrating on things such as reading the newspaper or watching television required

8. Moving or speaking so slowly that other people could notice? Or the opposite — being so agitated or restless that you move around much more than usual required

9. Thinking about hurting yourself in some way or that you would be better off dead required

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Conditions of use

Check the population, units, inclusion and exclusion criteria, and version in the original source. A result alone does not establish a diagnosis, discharge decision or prescription.

Documented parameters

Over the last 2 weeks, how often have you been bothered by… 1. Little interest or pleasure in doing things
2. Feeling down, depressed or without hope
3. Trouble falling or staying asleep, or sleeping more than usual
4. Feeling tired or having little energy
5. Poor appetite or overeating
6. Feeling bad about yourself — or feeling you are a failure or have let yourself or your family down
7. Trouble concentrating on things such as reading the newspaper or watching television
8. Moving or speaking so slowly that other people could notice? Or the opposite — being so agitated or restless that you move around much more than usual
9. Thinking about hurting yourself in some way or that you would be better off dead

5/5 reference cases checked. Numerical tests are not clinical validation.

Sources and documentation

Documented formula

Transcribed from the source or a recorded revision; this is not a clinical recommendation.

Each item scores 0 (not at all) – 3 (nearly every day). Total: 0 – 27.

Usual cutoff: ≥ 10 (sensitivity and specificity 88% for major depression in the original study). In the Brazilian general population (Santos 2013), ≥ 9: sensitivity 77.5%; specificity 86.7%.

Any response other than “not at all” on item 9 requires suicide-risk assessment regardless of total.

References

Identifier: phq-9

Original clinical content: Brazilian Portuguese.

Method version

PHQ-9/Kroenke 2001: 9 items 0–3, total 0–27; original cutoff 10 versus Brazilian Santos 2013≥9; item 9 alert

phq-9@native-2026-10-05+32327993073d

Source for the active edition

The bibliographic edition identifies the source. By itself, it proves neither full conformity of the formula nor clinical approval.

Synthetic cases checked (5)

Synthetic cases for checking the implementation, with no patient data.

Case 1

reference-001

Inputs

Over the last 2 weeks, how often have you been bothered by…1. Little interest or pleasure in doing things: Never
2. Feeling down, depressed or without hope: Never
3. Trouble falling or staying asleep, or sleeping more than usual: Never
4. Feeling tired or having little energy: Never
5. Poor appetite or overeating: Never
6. Feeling bad about yourself — or feeling you are a failure or have let yourself or your family down: Never
7. Trouble concentrating on things such as reading the newspaper or watching television: Never
8. Moving or speaking so slowly that other people could notice? Or the opposite — being so agitated or restless that you move around much more than usual: Never
9. Thinking about hurting yourself in some way or that you would be better off dead: Never

{
  "q1": "0",
  "q2": "0",
  "q3": "0",
  "q4": "0",
  "q5": "0",
  "q6": "0",
  "q7": "0",
  "q8": "0",
  "q9": "0"
}

Expected result

{
  "score": 0,
  "item9": 0
}

Actual result

{
  "score": 0,
  "item9": 0
}

Case 2

reference-002

Inputs

Over the last 2 weeks, how often have you been bothered by…1. Little interest or pleasure in doing things: More than half the days
2. Feeling down, depressed or without hope: Never
3. Trouble falling or staying asleep, or sleeping more than usual: Several days
4. Feeling tired or having little energy: Several days
5. Poor appetite or overeating: Several days
6. Feeling bad about yourself — or feeling you are a failure or have let yourself or your family down: Never
7. Trouble concentrating on things such as reading the newspaper or watching television: Never
8. Moving or speaking so slowly that other people could notice? Or the opposite — being so agitated or restless that you move around much more than usual: Never
9. Thinking about hurting yourself in some way or that you would be better off dead: Never

{
  "q1": "2",
  "q2": "0",
  "q3": "1",
  "q4": "1",
  "q5": "1",
  "q6": "0",
  "q7": "0",
  "q8": "0",
  "q9": "0"
}

Expected result

{
  "score": 5
}

Actual result

{
  "score": 5,
  "item9": 0
}

Case 3

reference-003

Inputs

Over the last 2 weeks, how often have you been bothered by…1. Little interest or pleasure in doing things: More than half the days
2. Feeling down, depressed or without hope: More than half the days
3. Trouble falling or staying asleep, or sleeping more than usual: More than half the days
4. Feeling tired or having little energy: More than half the days
5. Poor appetite or overeating: Several days
6. Feeling bad about yourself — or feeling you are a failure or have let yourself or your family down: Several days
7. Trouble concentrating on things such as reading the newspaper or watching television: Never
8. Moving or speaking so slowly that other people could notice? Or the opposite — being so agitated or restless that you move around much more than usual: Never
9. Thinking about hurting yourself in some way or that you would be better off dead: Never

{
  "q1": "2",
  "q2": "2",
  "q3": "2",
  "q4": "2",
  "q5": "1",
  "q6": "1",
  "q7": "0",
  "q8": "0",
  "q9": "0"
}

Expected result

{
  "score": 10
}

Actual result

{
  "score": 10,
  "item9": 0
}

Case 4

reference-004

Inputs

Over the last 2 weeks, how often have you been bothered by…1. Little interest or pleasure in doing things: Nearly every day
2. Feeling down, depressed or without hope: Nearly every day
3. Trouble falling or staying asleep, or sleeping more than usual: Nearly every day
4. Feeling tired or having little energy: Nearly every day
5. Poor appetite or overeating: Nearly every day
6. Feeling bad about yourself — or feeling you are a failure or have let yourself or your family down: Nearly every day
7. Trouble concentrating on things such as reading the newspaper or watching television: Nearly every day
8. Moving or speaking so slowly that other people could notice? Or the opposite — being so agitated or restless that you move around much more than usual: Nearly every day
9. Thinking about hurting yourself in some way or that you would be better off dead: Never

{
  "q1": "3",
  "q2": "3",
  "q3": "3",
  "q4": "3",
  "q5": "3",
  "q6": "3",
  "q7": "3",
  "q8": "3",
  "q9": "0"
}

Expected result

{
  "score": 24,
  "item9": 0
}

Actual result

{
  "score": 24,
  "item9": 0
}

Case 5

reference-005

Inputs

Over the last 2 weeks, how often have you been bothered by…1. Little interest or pleasure in doing things: Several days
2. Feeling down, depressed or without hope: Several days
3. Trouble falling or staying asleep, or sleeping more than usual: Never
4. Feeling tired or having little energy: Several days
5. Poor appetite or overeating: Never
6. Feeling bad about yourself — or feeling you are a failure or have let yourself or your family down: Never
7. Trouble concentrating on things such as reading the newspaper or watching television: Never
8. Moving or speaking so slowly that other people could notice? Or the opposite — being so agitated or restless that you move around much more than usual: Never
9. Thinking about hurting yourself in some way or that you would be better off dead: Several days

{
  "q1": "1",
  "q2": "1",
  "q3": "0",
  "q4": "1",
  "q5": "0",
  "q6": "0",
  "q7": "0",
  "q8": "0",
  "q9": "1"
}

Expected result

{
  "score": 4,
  "item9": 1
}

Actual result

{
  "score": 4,
  "item9": 1
}

Code and reproducibility

This tool’s code on GitHub

Download code and tests

Sources, version and reproduction instructions

README

Local installation

Code license: Apache-2.0

Guidelines and conditions

This repository’s license applies to the code. Third-party instruments, questionnaires, data and models remain subject to their owners’ conditions.

The code tests are technical checks. Clinical approval and professional translation review are recorded separately.

Relationship with cancer research

General context — relationship to be defined

A resource for general clinical contexts. This edition does not assign a specific oncological relationship; selecting it for a study requires a justified question, population and purpose.