# Depression Screening

> Use when screening for depression symptoms (low mood, anhedonia, fatigue, sleep changes, appetite changes), assessing severity for treatment planning, tracking treatment response, or patient has positive PHQ-9 Item 9 (suicidal ideation). Provides PHQ-9 (comprehensive) and PHQ-2 (brief) assessments.

- Skill: `majiayu000/depression-screening` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add majiayu000/depression-screening`
- Raw SKILL.md: https://api.skillmd.com/api/skills/majiayu000/depression-screening/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: majiayu000 (https://skillmd.com/u/majiayu000)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/majiayu000/depression-screening

---


# Depression Screening

## Description

This skill helps administer and interpret validated depression screening instruments. The PHQ-2 serves as a brief initial screener, while the PHQ-9 provides comprehensive assessment of depression severity aligned with DSM criteria.

**Clinical Context:** These tools help quantify depression symptoms, track treatment response, and support clinical decision-making. They are support tools that supplement, not replace, comprehensive clinical evaluation.

## Quick Reference

### Assessment Comparison

| Assessment | Items | Time | Purpose | Cutoff | When to Use |
|------------|-------|------|---------|--------|-------------|
| **PHQ-2** | 2 | <1 min | Brief screening | ≥3 → Full PHQ-9 | Time-limited settings, universal screening |
| **PHQ-9** | 9 | 2-3 min | Severity assessment | ≥10 = Moderate+ | Comprehensive assessment, treatment monitoring |

**For detailed comparison:** See [references/screening-comparison.md](references/screening-comparison.md)

### PHQ-9 Severity Levels

| Score | Severity | First-Line Treatment | Follow-up |
|-------|----------|---------------------|-----------|
| 0-4 | Minimal | Monitor, psychoeducation | Annual or as needed |
| 5-9 | Mild | Behavioral interventions | 2-4 weeks |
| 10-14 | Moderate | Therapy or medication | 2-4 weeks |
| 15-19 | Moderately Severe | Combination therapy, specialty referral | 1-2 weeks |
| 20-27 | Severe | Specialty referral, higher level of care | Weekly+ |

**For detailed severity interpretations:** See [references/severity-levels.md](references/severity-levels.md)

**For treatment recommendations:** See [references/clinical-decision-trees.md](references/clinical-decision-trees.md)

## ⚠️ CRITICAL SAFETY WARNING

### PHQ-9 Item 9: Suicidal Ideation

**Item 9:** "Thoughts that you would be better off dead or of hurting yourself in some way"

**ANY score > 0 on Item 9 requires IMMEDIATE action:**
1. **Stop** and address immediately - do not wait until end of assessment
2. **Assess** safety fully (ideation, plan, intent, means, protective factors)
3. **Intervene** based on risk level (safety plan, crisis resources, emergency evaluation)
4. **Document** thoroughly

#### Item 9 Response Protocol

```dot
digraph item9_protocol {
    rankdir=TB;
    node [shape=box, style=rounded];

    item9 [label="PHQ-9 Item 9\nscore > 0", shape=ellipse, style="filled", fillcolor=orange];
    stop [label="STOP\nAssessment", style="filled", fillcolor=red, fontcolor=white];
    assess [label="Assess Safety:\n• Active ideation?\n• Plan/intent?\n• Means access?\n• Protective factors?", style="filled", fillcolor=yellow];
    risk_level [label="Risk Level?", shape=diamond];
    low [label="Low Risk:\n• Safety plan\n• Follow-up\n• Resources", style="filled", fillcolor=lightgreen];
    moderate [label="Moderate Risk:\n• Safety plan\n• Crisis contacts\n• Urgent referral\n• Reduce means", style="filled", fillcolor=yellow];
    high [label="High Risk:\n• Do not leave alone\n• Emergency eval\n• 988/911\n• Family notification", style="filled", fillcolor=red, fontcolor=white];
    document [label="Document\nThoroughly", style="filled", fillcolor=lightblue];

    item9 -> stop;
    stop -> assess;
    assess -> risk_level;
    risk_level -> low [label="Low"];
    risk_level -> moderate [label="Moderate"];
    risk_level -> high [label="High/\nImminent"];
    low -> document;
    moderate -> document;
    high -> document;
}
```

**See detailed protocol:** [references/item-9-safety-protocol.md](references/item-9-safety-protocol.md)

**Crisis Resources:**
- **988 Suicide & Crisis Lifeline** (call or text)
- **Crisis Text Line:** Text HOME to 741741
- **Emergency:** 911

**Universal crisis protocols:** [../../docs/references/crisis-protocols.md](../../docs/references/crisis-protocols.md)

## Interactive Administration (Optional)

Use this mode when the clinician says "start" or "administer" the PHQ-2/PHQ-9.

1. Confirm readiness and explain the past 2 weeks time frame plus the 0-3 response scale.
2. Ask one item at a time (verbatim from the asset file) and wait for a response before continuing.
3. Accept numeric or verbal responses; if unclear or out of range, ask for clarification.
4. Record each response and keep a running total.
5. **Item 9 safety rule:** If Item 9 > 0, STOP and follow the Item 9 safety protocol before continuing.
6. After the final item, calculate the total score, interpret severity, and provide next-step guidance.
7. Offer a brief documentation summary if requested.

## Assessment Tools

### PHQ-9 (Patient Health Questionnaire-9)

**Complete assessment with items, scoring, and documentation:**
→ [assets/phq-9.md](assets/phq-9.md)

**Key Facts:**
- **9 items**, 0-3 scale each, total score 0-27
- **Cutoff ≥10:** 88% sensitivity/specificity for major depression
- **Item 9:** Screens for suicidal ideation - requires immediate follow-up if positive
- **Treatment response:** 5-point decrease = response, 10-point = clinically significant
- **Validated** for screening, diagnosis support, and treatment monitoring

### PHQ-2 (Patient Health Questionnaire-2)

**Complete assessment with items, scoring, and documentation:**
→ [assets/phq-2.md](assets/phq-2.md)

**Key Facts:**
- **2 items** (first 2 from PHQ-9), 0-3 scale each, total score 0-6
- **Cutoff ≥3:** Positive screen → administer full PHQ-9
- **Use for:** Rapid screening, universal screening in time-limited settings
- **Does NOT:** Assess severity or include suicidal ideation screening

**When to use PHQ-2 vs PHQ-9:** See [references/screening-comparison.md](references/screening-comparison.md)

## Clinical Workflow

### 1. Choose Assessment

```dot
digraph assessment_selection {
    rankdir=LR;
    node [shape=box, style=rounded];

    start [label="Patient\nPresentation", shape=ellipse];
    time_check [label="Time-limited\nencounter?", shape=diamond];
    purpose_check [label="Treatment\nmonitoring?", shape=diamond];
    phq2 [label="Start with\nPHQ-2", style="filled", fillcolor=lightblue];
    phq2_score [label="PHQ-2\nscore ≥3?", shape=diamond];
    phq9 [label="Administer\nPHQ-9", style="filled", fillcolor=lightgreen];
    monitor [label="Negative\nscreen", style="filled", fillcolor=gray90];

    start -> time_check;
    time_check -> phq2 [label="yes\n(primary care,\nER)"];
    time_check -> purpose_check [label="no"];
    purpose_check -> phq9 [label="yes"];
    purpose_check -> phq9 [label="no\n(suspected\ndepression)"];
    phq2 -> phq2_score;
    phq2_score -> phq9 [label="yes"];
    phq2_score -> monitor [label="no"];
}
```

### 2. Administer Assessment

**PHQ-2:** [assets/phq-2.md](assets/phq-2.md) - 2 items, <1 minute
**PHQ-9:** [assets/phq-9.md](assets/phq-9.md) - 9 items, 2-3 minutes

### 3. Score and Interpret

**Scoring:**
- Sum all item responses
- PHQ-2: 0-6 range
- PHQ-9: 0-27 range

**Interpretation:**
- See quick reference table above
- Detailed interpretations: [references/severity-levels.md](references/severity-levels.md)

**⚠️ Check Item 9 immediately** - if positive, see safety protocol

### 4. Clinical Decision-Making

#### Treatment Decision Pathway

```dot
digraph treatment_decision {
    rankdir=TB;
    node [shape=box, style=rounded];

    score [label="PHQ-9\nTotal Score", shape=ellipse];
    minimal [label="0-4\nMinimal", shape=box];
    mild [label="5-9\nMild", shape=box];
    moderate [label="10-14\nModerate", shape=box];
    mod_severe [label="15-19\nMod. Severe", shape=box];
    severe [label="20-27\nSevere", shape=box];

    tx_minimal [label="• Monitor\n• Psychoeducation\n• Annual f/u", style="filled", fillcolor=gray90];
    tx_mild [label="• Behavioral interventions\n• Lifestyle changes\n• F/u 2-4 weeks", style="filled", fillcolor=lightblue];
    tx_moderate [label="• Therapy OR\n  medication\n• F/u 2-4 weeks", style="filled", fillcolor=yellow];
    tx_mod_severe [label="• Combination therapy\n• Specialty referral\n• F/u 1-2 weeks", style="filled", fillcolor=orange];
    tx_severe [label="• Immediate specialty\n• Higher LOC\n• Weekly+ f/u", style="filled", fillcolor=red, fontcolor=white];

    score -> minimal;
    score -> mild;
    score -> moderate;
    score -> mod_severe;
    score -> severe;

    minimal -> tx_minimal;
    mild -> tx_mild;
    moderate -> tx_moderate;
    mod_severe -> tx_mod_severe;
    severe -> tx_severe;
}
```

**Follow clinical decision trees:** [references/clinical-decision-trees.md](references/clinical-decision-trees.md)

**⚠️ Any Item 9 > 0:** Follow safety protocol regardless of total score

### 5. Document

**Use documentation templates in:**
- [assets/phq-2.md](assets/phq-2.md#documentation-template)
- [assets/phq-9.md](assets/phq-9.md#documentation-template)

**Documentation standards:** [../../docs/references/documentation-standards.md](../../docs/references/documentation-standards.md)

## Treatment Monitoring

**Use PHQ-9 to track progress:**
- **Baseline:** Administer at treatment start
- **Follow-up:** Every 2-4 weeks during active treatment
- **Response indicators:**
  - <5-point decrease: Minimal response (consider treatment change)
  - 5-9 point decrease: Partial response (continue, monitor)
  - ≥10-point decrease: Clinically significant improvement
  - Score <5: Remission (treatment goal)

**Do NOT use PHQ-2 for treatment monitoring** - insufficient detail

## Special Considerations

- **Medical comorbidity:** Physical illness elevates somatic scores (items 3,4,5,8)—interpret in context, treat depression regardless
- **Cultural factors:** Symptom expression varies; use culturally validated versions when available
- **Age:** PHQ-A for adolescents; validated for older adults; different tools for children <12
- **Substance use:** Can confound scores; assess post-detox for baseline; integrated treatment required

## Referral Guidelines

### When to Refer to Specialty Mental Health

**Immediate/Urgent:**
- PHQ-9 ≥15 at initial presentation
- Any suicidal ideation (Item 9 > 0)
- Inadequate response to initial treatment
- Patient request for specialty care

**Routine:**
- PHQ-9 10-14 if patient prefers specialist
- Complex presentation (trauma, substance use, medical comorbidity)
- Need for specialized therapy

**Complete referral guidance:** [../../docs/references/referral-guidelines.md](../../docs/references/referral-guidelines.md)

## Limitations

**Screening tools, not diagnostic instruments.** Do not replace clinical assessment. Clinical judgment supersedes scores. Potential issues: false positives (medical illness), false negatives (minimization, literacy), cultural/linguistic factors.

## Usage Examples

**Example requests:** "Administer PHQ-9", "Screen for depression", "Score and interpret PHQ-9", "Treatment for score 16", "Item 9 positive—what now?"

## References

**Primary Literature:**
- Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001;16(9):606-613.
- Kroenke K, Spitzer RL, Williams JB. The Patient Health Questionnaire-2: validity of a two-item depression screener. Med Care. 2003;41(11):1284-1292.

**Clinical Guidelines:**
- American Psychological Association. (2019). Clinical Practice Guideline for the Treatment of Depression.
- Veterans Affairs/DoD. (2022). Clinical Practice Guideline for Management of Major Depressive Disorder.

**No copyright restrictions - PHQ-2 and PHQ-9 are freely available for clinical and research use**