Is the result a diagnosis?

No. The PHQ-9 shows how strongly depressive symptoms have affected the patient recently. Only a doctor or psychotherapist can diagnose depression after a full assessment.

What happens if the patient answers question 9 with anything other than “Not at all”?

Question 9 asks about thoughts of death or self-harm. If the patient has had such thoughts, we show where to find immediate help. Please take these thoughts seriously and make sure the patient talks to someone – a crisis line, a doctor or a person they trust.

Why is the last question not counted?

The final question asks how much the symptoms affect the patient's work, home life and relationships. It is not part of the score, but it helps show how much the symptoms are affecting their everyday life.

Can alcohol or drugs affect the result?

Yes. Substance use and withdrawal can both cause or worsen symptoms like low mood, sleep problems and tiredness. If this applies to the patient, note it when the result is discussed with a professional.

Can it be filled in more than once?

Yes. The PHQ-9 is well suited to repeating every few weeks, so you can see whether the patient's symptoms are getting better or worse.

Are the responses stored?

No. The responses are processed only in your browser and are not sent or saved anywhere.

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PHQ-9

Patient Health Questionnaire-9

A short questionnaire that measures how strongly symptoms of depression have affected the patient over the last two weeks.

Category: Depression
Who fills it in: Self-report
Items: 9
Recall period: Last 2 weeks

On this page

Administer the scale

0 of 9 completed

Record the patient's response to every item. Entries stay in your browser and are never sent anywhere.

Over the last 2 weeks, how often have you been bothered by any of the following problems?

1. Little interest or pleasure in doing things
Little interest or pleasure in doing things
Not at allSeveral daysMore than half the daysNearly every day

Question 1 of 9

What it measures

The PHQ-9 measures how severe depressive symptoms are. Each of the nine questions is scored from 0 to 3, giving a total between 0 and 27. A final question asks how much the problems affect the patient's daily life; it is not counted in the score.

When to use it

Use the PHQ-9 when a patient has been feeling low or without energy, or has lost interest in things they usually enjoy. It is also useful when the patient drinks or uses drugs, since substances are often used to cope with low mood and can make it worse. Because it responds well to change, you can repeat it over time, for example during treatment.

Origin

The PHQ-9 was developed by Dr. Robert L. Spitzer, Dr. Janet B.W. Williams, Dr. Kurt Kroenke and colleagues, with an educational grant from Pfizer Inc. It is the depression module of the Patient Health Questionnaire (PHQ), a self-report version of an earlier diagnostic tool (PRIME-MD) developed in the 1990s for use in primary care. The PHQ-9 validation study was published in 2001.

Validation

The Patient Health Questionnaire was developed and validated in two large studies with 6,000 patients in general practice and gynaecology clinics. The PHQ-9 has since become one of the most thoroughly studied depression questionnaires. Research has also confirmed that it is sensitive to change, which makes it suitable for monitoring treatment. The German version (PHQ-D) has been validated in German-speaking samples.

Limitations

The PHQ-9 is a screening questionnaire, not a diagnosis. A diagnosis of depression requires a clinical assessment, which also rules out other explanations: normal grief after a loss, a history of manic episodes (as in bipolar disorder), and physical illness, medication, alcohol or drugs as the cause of the symptoms. The last point is particularly relevant for people who use substances, since intoxication and withdrawal can both cause depressive symptoms. The questionnaire only covers the last two weeks and relies on self-report. A positive answer to question 9, about thoughts of death or self-harm, always needs a personal conversation with a professional – the questionnaire alone cannot assess this risk.

Frequently asked questions

Is the result a diagnosis?: No. The PHQ-9 shows how strongly depressive symptoms have affected the patient recently. Only a doctor or psychotherapist can diagnose depression after a full assessment.
What happens if the patient answers question 9 with anything other than “Not at all”?: Question 9 asks about thoughts of death or self-harm. If the patient has had such thoughts, we show where to find immediate help. Please take these thoughts seriously and make sure the patient talks to someone – a crisis line, a doctor or a person they trust.
Why is the last question not counted?: The final question asks how much the symptoms affect the patient's work, home life and relationships. It is not part of the score, but it helps show how much the symptoms are affecting their everyday life.
Can alcohol or drugs affect the result?: Yes. Substance use and withdrawal can both cause or worsen symptoms like low mood, sleep problems and tiredness. If this applies to the patient, note it when the result is discussed with a professional.
Can it be filled in more than once?: Yes. The PHQ-9 is well suited to repeating every few weeks, so you can see whether the patient's symptoms are getting better or worse.
Are the responses stored?: No. The responses are processed only in your browser and are not sent or saved anywhere.

References

Kroenke K, Spitzer RL, Williams JBW. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16:606-613.
Spitzer RL, Kroenke K, Williams JBW, for the Patient Health Questionnaire Primary Care Study Group. Validation and utility of a self-report version of PRIME-MD: the PHQ Primary Care Study. JAMA. 1999;282:1737-1744.
Kroenke K, Spitzer RL. The PHQ-9: a new depression diagnostic and severity measure. Psychiatric Annals. 2002;32:509-521.
Löwe B, Unützer J, Callahan CM, Perkins AJ, Kroenke K. Monitoring depression treatment outcomes with the Patient Health Questionnaire-9. Med Care. 2004;42:1194-1201.
Gräfe K, Zipfel S, Herzog W, Löwe B. Screening psychischer Störungen mit dem „Gesundheitsfragebogen für Patienten (PHQ-D)“. Diagnostica. 2004;50(4):171-181.
Kroenke K, Spitzer RL, Williams JBW, Löwe B. The Patient Health Questionnaire somatic, anxiety, and depressive symptom scales: a systematic review. Gen Hosp Psychiatry. 2010;32:345-359.
Instructions for Patient Health Questionnaire (PHQ) and GAD-7 Measures. Instruction manual, www.phqscreeners.com.

Licence & attribution

Developed by Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke and colleagues, with an educational grant from Pfizer Inc. No permission required to reproduce, translate, display or distribute.

Public domain.