PHQ-2 Depression Screening Calculator
The PHQ-2 is a validated two-question depression screen used worldwide by clinicians. It asks how often, over the past two weeks, you have been bothered by low interest or pleasure and by depressed mood. Each answer is scored 0-3, giving a total of 0-6. A score of 3 or higher is a positive screen and warrants a full PHQ-9 assessment. This calculator scores both questions instantly, shows the positive predictive value and likelihood ratio for your score, and explains what the result means and what to do next.
What is the PHQ-2?
The Patient Health Questionnaire-2 (PHQ-2) is a two-item depression screening tool derived from the longer PHQ-9. It was validated by Kroenke, Spitzer, and Williams in a landmark 2003 study of approximately 6000 primary care patients. The two questions capture the two cardinal features that DSM criteria require for a diagnosis of major depressive disorder: depressed mood and anhedonia (loss of interest or pleasure). By limiting the screen to just two items, the PHQ-2 can be completed in under a minute, making it practical for busy clinical settings such as general practice, emergency departments, and maternal health checkups. The PHQ-2 does not diagnose depression; it identifies people who are likely to benefit from a fuller assessment.
How scoring and interpretation work
Each question is answered on a four-point frequency scale: Not at all (0), Several days (1), More than half the days (2), or Nearly every day (3). The two scores are summed for a total ranging from 0 to 6. A total of 3 or more is a positive screen. At a score of 3, the original validation data show a major depressive disorder positive predictive value of about 38% and a likelihood ratio of 2.9. The values rise steeply with score: a perfect score of 6 carries a MDD PPV of about 79% and a likelihood ratio of 48. A negative result does not rule out depression entirely, but it substantially lowers the probability in unselected populations. Clinical guidelines recommend following a positive PHQ-2 with the full nine-item PHQ-9, which measures severity across all DSM symptom domains and includes a suicidality question the PHQ-2 omits.
Cutoff choice and diagnostic accuracy
The standard cutoff of 3 was selected in the original validation study as the optimal balance between sensitivity and specificity. At a cutoff of 3, the PHQ-2 achieves roughly 83% sensitivity and 92% specificity against a structured diagnostic interview, meaning it catches most true depression cases while keeping false positives low. Lowering the cutoff to 2 raises sensitivity (potentially above 95%) but also increases false positives; raising it to 4 improves specificity but risks missing genuine cases. Most clinical guidelines use the cutoff of 3. Some high-sensitivity contexts, such as perinatal mental health screening, use 2. In any setting, a positive screen should be confirmed by clinical assessment rather than taken alone as a diagnosis.
When and how to use the PHQ-2 in practice
The PHQ-2 is most useful as a rapid first-pass filter before the more detailed PHQ-9. Clinicians commonly administer it at the start of a consultation or on an intake form. A positive result triggers the PHQ-9, a brief mental health interview, and consideration of risk factors such as prior episodes, family history, psychosocial stressors, and medical comorbidities. The PHQ-2 is validated for adults; its accuracy in children and adolescents is less established and dedicated pediatric tools such as the PHQ-A are preferred for those groups. The tool was originally validated in English; validated translations exist for many languages, and clinicians should use culturally adapted versions where available.
PHQ-2 Score Interpretation (Kroenke et al., 2003)
| PHQ-2 Score | Screen Result | MDD PPV | MDD LR | Any Depressive Disorder PPV | Any Depressive Disorder LR |
|---|---|---|---|---|---|
| 0 | Negative | N/A | N/A | N/A | N/A |
| 1 | Negative | 15.4% | 0.3 | 36.9% | 0.6 |
| 2 | Negative | 21.1% | 0.6 | 48.3% | 1.3 |
| 3 | Positive | 38.4% | 2.9 | 75.0% | 5.4 |
| 4 | Positive | 45.4% | 5.5 | 81.2% | 15.7 |
| 5 | Positive | 56.4% | 10.3 | 84.6% | 17.9 |
| 6 | Positive | 78.6% | 48.2 | 92.9% | 58.1 |
Positive predictive values and likelihood ratios from the original validation study (N = 6000). PPV = probability of disorder at that score. LR = likelihood ratio. MDD = major depressive disorder.
Frequently asked questions
What does a PHQ-2 score of 3 or more mean?
A score of 3 or more is a positive screen. It does not diagnose depression, but it indicates that you are likely experiencing significant depressive symptoms and should be evaluated further, ideally with the full PHQ-9 and a conversation with a healthcare provider. At a score of 3, the validation data show roughly a 38% chance of major depressive disorder and a 75% chance of any depressive disorder.
Is the PHQ-2 a diagnosis of depression?
No. The PHQ-2 is a screening tool, not a diagnostic test. A positive screen means further assessment is warranted. A formal diagnosis of depression requires a full clinical evaluation that considers symptom duration, functional impairment, medical causes (such as hypothyroidism), medication side effects, and ruling out other psychiatric conditions.
What happens after a positive PHQ-2 screen?
A positive PHQ-2 should lead to administration of the full PHQ-9, which rates all nine DSM depression symptom domains and classifies severity as minimal, mild, moderate, moderately severe, or severe. If the PHQ-9 also indicates significant symptoms, a clinician will discuss treatment options including psychotherapy, medication, lifestyle changes, and referral to a mental health specialist.
Can I use the PHQ-2 on its own to decide on treatment?
No. Treatment decisions should never be based on the PHQ-2 alone. The two-question screen is designed to open a clinical conversation, not to close one. A thorough assessment by a qualified healthcare professional is needed before starting or changing treatment.
How is the PHQ-2 different from the PHQ-9?
The PHQ-2 contains the first two items of the PHQ-9 and is used as a rapid filter. The PHQ-9 covers all nine DSM major depressive episode criteria, provides a severity score (0-27), includes a suicidality question, and is suitable for monitoring treatment response. The PHQ-2 is faster (under one minute) but provides less clinical detail. A positive PHQ-2 should be followed by the full PHQ-9.
What is the difference between PPV and likelihood ratio in the score table?
The positive predictive value (PPV) is the probability that a person with that score actually has the disorder, assuming a typical primary care population where about 10% of patients have major depression. The likelihood ratio (LR) tells you how many times more likely a positive test result is in someone with the disease compared to someone without it, and can be applied to any pre-test probability using Bayes rule. Higher scores produce both higher PPVs and higher LRs, meaning the result is more informative.