The PHQ-9 measures depression symptoms. The GAD-7 measures anxiety symptoms. Both cover the past two weeks and use 0-to-3 responses, but their totals have different ranges and must stay separate. Use one for a focused question or both when both symptom groups need review.
Neither questionnaire provides a diagnosis or treatment plan.
The main differences
| Feature | PHQ-9 | GAD-7 |
|---|---|---|
| Main focus | Depression symptoms | Anxiety symptoms |
| Scored items | 9 | 7 |
| Timeframe | Past 2 weeks | Past 2 weeks |
| Response values | 0 to 3 | 0 to 3 |
| Total range | 0 to 27 | 0 to 21 |
| Descriptive bands | 5 | 4 |
| Direct safety item | Yes, item 9 | No |
| Optional functional item | Stored outside the total | Stored outside the total |
The similar format makes the pair easy to administer together. It does not make the scores equivalent. A PHQ-9 total of 12 and a GAD-7 total of 12 describe different questions on different ranges.
What the PHQ-9 measures
The PHQ-9 covers nine areas used in depression assessment. They include mood, interest, sleep, energy, appetite, self-worth, concentration, movement, and thoughts of death or self-harm. The total summarizes how often those symptoms were reported.
Item 9 needs its own review. Any answer above zero calls for a direct safety conversation, whatever the total or band. The PHQ-9 is not a complete suicide risk assessment, and the GAD-7 has no item that can replace one.
If you need help now. In the US, Call 988 or text 988. Call 911 if you are in immediate danger. Outside the US, contact your local emergency number or find support in your country.
For a result-focused explanation, read what your PHQ-9 score means.
What the GAD-7 measures
The GAD-7 covers worry, difficulty controlling worry, tension, trouble relaxing, restlessness, irritability, and fear. The total describes reported anxiety symptom frequency. It cannot identify the cause or confirm a specific anxiety disorder.
The questionnaire has no direct suicide or self-harm item. Safety still needs separate review whenever the person's answers, history, or current situation raise concern.
For the scoring details, read what your GAD-7 score means.
Read each score on its own scale
The original PHQ-9 adult validation study supports these five bands:
| PHQ-9 score | Description |
|---|---|
| 0-4 | None or minimal |
| 5-9 | Mild |
| 10-14 | Moderate |
| 15-19 | Moderately severe |
| 20-27 | Severe |
The original GAD-7 adult primary-care study supports these four bands:
| GAD-7 score | Description |
|---|---|
| 0-4 | Minimal |
| 5-9 | Mild |
| 10-14 | Moderate |
| 15-21 | Severe |
Both moderate bands begin at 10. That shared boundary does not combine the constructs or make their performance identical across populations. The labels describe symptom frequency. They do not prescribe care.
When one questionnaire may fit
Use the PHQ-9 when depression symptoms are the focused question or when its direct safety item belongs in the workflow. Use the GAD-7 when anxiety and worry are the focused question.
One questionnaire may be enough for a narrow follow-up. Yet a low score cannot rule out concerns the form does not ask about. Panic, trauma reactions, grief, mania, substance effects, and physical illness may require different questions or a broader assessment.
The DASS-21 comparison explains another option when separate depression, anxiety, and stress domains are useful.
When both may help
Using both can show whether depression symptoms, anxiety symptoms, or both were reported. Keep the two totals beside each other with clear labels. Do not add them, average them, or use the higher number as the more important condition.
If both totals are elevated, the result supports review of both symptom patterns. It does not establish two diagnoses. If one total is higher, inspect the answers and daily impact rather than treating the numeric gap as a diagnosis or treatment priority.
If both are low, listen to the concern that prompted screening. Short questionnaires leave things out.
For a step-by-step workflow, see how to score the PHQ-9 and GAD-7 together.
Functional impact remains separate
Survey Doctor offers an optional functional-difficulty question after any scored item on that questionnaire is above zero. The selected answer is stored separately. It never changes the PHQ-9 or GAD-7 total.
An all-zero native result does not show that question. A record without functional data means the answer was not collected. Ask about work, home responsibilities, relationships, and other daily activities because equal totals can accompany very different levels of difficulty.
Native, manual, and imported results differ
A native Survey Doctor result requires every scored item. It can preserve the answer pattern, PHQ-9 item 9 status, and any optional functional response.
Manual entry accepts one whole-number total within the questionnaire's native range. A manual total cannot prove which items were endorsed, whether every item was answered, whether PHQ-9 item 9 was positive, or whether the functional question was shown.
Some imported historical summaries lack enough evidence to confirm the form, completion, or scoring method. Survey Doctor displays saved numeric scores in reports. Displaying those numbers does not make them equivalent to current native results.
Check the original record before applying either questionnaire's bands or comparing it with a new result. A number within the expected range cannot establish which questions were answered or how the total was calculated.
Comparing results over time
Keep a separate history for each questionnaire. Compare complete results from the same form under similar conditions, then review the answers and functional context.
There is no universal point change, percentage change, remission threshold, or retest interval that applies to both scales in every setting. A band crossing can reflect a one-point move. An unchanged total can hide important changes among symptoms.
The bottom line
The PHQ-9 is a nine-item depression measure with a 0-to-27 total and a direct safety item. The GAD-7 is a seven-item anxiety measure with a 0-to-21 total and no direct safety item.
Use the questionnaire that matches the question. Use both when both symptom groups need review, but score and interpret them separately.