9 Questions to Ask When Screening for Depression

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Have you experienced any depressive symptoms over the past two weeks? Do you think you could be suffering from clinical depression?

If so, you might want to consider filling out a brief Patient Health Questionnaire called the PHQ-9. This nine-item questionnaire is a well-validated first step when screening for depression. However, PHQ-9 scores are not a diagnosis.

Note: Before going into more detail about the PHQ-9, there is an important disclaimer. Screening yourself for depression is not a substitute for speaking with your doctor about specific depressive symptoms or seeking professional help. Your PHQ-9 score is just one facet of a much more detailed criteria-based diagnosis of a possible major depressive disorder (MDD).

What Is the PHQ-9?

The Patient Health Questionnaire (PHQ) is a self-reported version of a much more detailed clinician-administered screening tool called Primary Care Evaluation of Mental Disorders (PRIME-MD).

The PHQ-9 is a truncated version of the Patient Health Questionnaire that scores nine criteria for depressive disorders on a "0" (not at all) to "3" (nearly every day) scale.

In 1999, Robert Spitzer and Janet Williams of Columbia University and Kurt Kroenke of Indiana University conducted a primary care study that tested the validity and utility of the PHQ compared to PRIME-MD. "Our study (Spitzer, Kroenke, Williams, 1999) suggests that the PHQ has diagnostic validity comparable to the original clinician-administered PRIME-MD, and is more efficient to use," the authors concluded.

In 2001, Kurt Kroenke and his colleagues at Columbia conducted a follow-up study (Kroenke, Spitzer, Williams, 2001) that focused specifically on the validity of the PHQ-9. The authors sum up their findings: "In addition to making criteria-based diagnoses of depressive disorders, the PHQ-9 is also a reliable and valid measure of depression severity. These characteristics, plus its brevity, make the PHQ-9 a useful clinical and research tool."

There is an interactive online version of the Patient Health Questionnaire-9 that is designed to assist clinicians in making an initial diagnosis of depression, quantify depressive symptoms, and monitor depression severity. This online version of the PHQ-9 calculates scores automatically and gives recommendations for next steps. A PDF of the PHQ-9 is available here.

The initial prompt for the PHQ-9: "How often have you been bothered by the following over the past two weeks?" (Responses to the nine items below are answered on 0-3 scale; 0 = Not at All, 1 = Several Days, 2 = More Than Half the Days, 3 = Nearly Every Day.)

1. Little interest or pleasure in doing things
2. Feeling down, depressed, or hopeless
3. Trouble falling or staying asleep, or sleeping too much
4. Feeling tired or having little energy
5. Poor appetite or overeating
6. Feeling bad about yourself or that 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 have noticed. Or the opposite being so fidgety or restless that you have been moving around a lot more than usual
9. Thoughts that you would be better off dead or thoughts of hurting yourself

If someone reports being bothered by any items on the PHQ-9, there's a tenth question designed to assess possible impairment from depressive symptoms: "How difficult have these problems made it [for you] to do work, take care of things at home, or get along with other people?" (Response options: 1. Not at all, 2. Somewhat difficult, 3. Very difficult, 4. Extremely difficult.) Responses to this tenth question are not directly factored into someone's final PHQ-9 score.

Last year, researchers from McGill University published the findings of a meta-analysis (Levis, Benedetti, and Thombs, 2019) on the "accuracy of the Patient Health Questionnaire-9 (PHQ-9) for screening to detect major depression." This meta-analysis of 58 different studies was published in the journal Psychotherapy and Psychosomatics.

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Based on their meta-analysis, Brooke Levis, Andrea Benedetti, and Brett Thombs conclude that the PHQ-9 appears to be a useful screening tool for detecting major depression.

That said, there is another caveat: This meta-analysis also found that when the PHQ-9 is used in a primary care setting, only about 50 percent of patients who initially screen positive for depression on this 9-item questionnaire receive a final diagnosis of major depressive disorder.

Conclusions: The PHQ-9 is a well-validated screening tool for depression that can offer a "ballpark estimate" of depression severity. Although this self-reported questionnaire is a valuable tool, it also has significant limitations. For anyone who is clinically depressed or impaired by depressive symptoms, please reach out to a mental health professional or speak to your primary care physician about your depressive symptoms. Or contact the Suicide Prevention Lifeline (1-800-273-8255).

Other Resources: The U.S. Department of Health and Human Services operates a free, confidential, 24/7, 365-days-a-year treatment referral and information service for individuals and families facing mental health issues or substance abuse disorders. The government's Substance Abuse and Mental Health Services Administration (SAMHSA) national helpline number: 1-800-662-4357.

Lifeline Chat is a service of the National Suicide Prevention Lifeline that is available online anytime, day or night. Their telephone hotline (1-800-273-8255) also "provides 24/7, free and confidential support for people in distress, prevention and crisis resources for you or your loved ones, and best practices for professionals."