PHQ-15 (Patient Health Questionnaire-15)
The PHQ-15 is a brief, validated measure of somatic symptom severity commonly used in primary care, mental health, and integrated behavioural health settings. Developed as part of the broader Patient Health Questionnaire suite, the PHQ-15 quantifies the burden of physical symptoms that may be associated with anxiety, depression, stress, or somatic symptom disorders.
Its scoring system provides a clear indicator of symptom load, helping clinicians identify when somatic concerns may be clinically significant or require further assessment. While not diagnostic, the PHQ-15 is a practical tool for monitoring symptom intensity and guiding conversations around functional impairment, medical workup, and mind–body interactions.
Type: Somatic symptom severity scale
Population: Adults (18+)
Length: 15 items
Format: Self-report
Completion Time: 3–5 minutes
- At intake, particularly when patients present with multiple physical complaints
- Every 4–12 weeks, to monitor change during treatment
- As clinically indicated, when somatic symptoms worsen, fluctuate, or are a primary treatment target
PHQ-15 Score Interpreter
Low somatic symptom burden. Clinical context should guide whether follow-up is indicated.
15 items, each scored 0–2 (not bothered at all to bothered a lot); scores summed over the past 4 weeks.
| Total score | Interpretation |
|---|---|
| 15+ | HighHigh somatic symptom burden. Prompts thorough assessment of functional impairment, medical history, and psychological contributors. |
| 10–14 | ModerateModerate somatic symptom burden. May benefit from integrated behavioural health evaluation and closer monitoring. |
| 5–9 | LowLow somatic symptom burden. Clinical context should guide whether follow-up is indicated. |
| 0–4 | MinimalMinimal somatic symptoms reported. |
Kroenke K et al. Psychosom Med. 2002;64(2):258-266; Kroenke K et al. Gen Hosp Psychiatry. 2010;32(4):345-359. Severity ranges per original validation study and systematic review. Educational reference only — not a diagnostic tool.
Foundational Context
Somatic symptoms, such as pain, fatigue, dizziness, and gastrointestinal discomfort, are among the most common reasons individuals seek medical care. Kroenke, Spitzer, and Williams (2002) formalized the PHQ-15 to provide a structured, reliable way to quantify these symptoms and examine their impact on functioning. The scale consolidates a wide range of physical complaints from the original PHQ, reflecting domains frequently encountered across medical and mental health settings.
The PHQ-15 is clinically valuable because somatic symptoms often coexist with anxiety disorders, depressive disorders, trauma-related conditions, and stress-related physiology. High scores may also indicate potential somatic symptom disorder or signal the need for multidisciplinary care. The scale supports efficient screening, fosters shared decision-making, and encourages a biopsychosocial approach to care.
What the Assessment Measures
The PHQ-15 captures the frequency and severity of common somatic symptoms, reflecting both patient distress and functional impact. Symptoms span multiple systems, including:
- Pain (back pain, headaches, limb pain)
- Gastrointestinal symptoms (nausea, constipation, bloating)
- Fatigue and low energy
- Shortness of breath
- Dizziness
- Sleep and menstrual-related concerns (if applicable)
By focusing on symptom burden rather than etiology, the PHQ-15 allows clinicians to identify patterns, track changes, and determine when further medical evaluation or integrated mental health support is appropriate.
Interpretation Guidelines
The PHQ-15 generates a total score (0–30) based on how much symptoms have bothered the respondent in the past four weeks.
Validated severity thresholds:
- 0–4: Minimal somatic symptoms
- 5–9: Low somatic symptom severity
- 10–14: Moderate somatic symptom severity
- 15+: High somatic symptom severity
Interpretation Notes:
- Higher scores indicate greater overall symptom burden, not a specific diagnosis.
- Moderate to high scores should prompt assessment of functional impairment, medical history, stressors, mood, anxiety, and trauma exposure.
- Somatic symptoms may be influenced by chronic illness, pain conditions, psychological factors, or lifestyle.
- Cultural differences can affect how physical symptoms are expressed or reported.
- The PHQ-15 should be interpreted alongside clinical judgment, patient history, and appropriate medical evaluation.
Psychometric Properties
Reliability
- Good internal consistency across diverse medical and psychiatric populations
- Stable measurement across repeated administrations during treatment
Validity
- Strong correlations with functional impairment, depression, and anxiety
- Demonstrated ability to identify individuals at risk for somatic symptom disorders
- Predictive of healthcare utilization, including frequent primary care visits
- Sensitivity to change, supporting its use for monitoring treatment response
Administration Considerations
- Best administered when exploring physical symptoms, especially when multiple complaints are present
- Useful for fostering discussion about mind–body connections, coping, and treatment planning
- Should be paired with clinical evaluation to determine whether symptoms require medical workup
- Helps differentiate between isolated physical symptoms and broader somatic patterns
- May support integrated behavioural health interventions when scores are moderate to high
Limitations
- Not diagnostic for somatic symptom disorder or any specific medical condition
- High scores can reflect medical illness, psychological distress, or both
- Self-report may be influenced by health literacy, cultural norms, or response style
- Does not assess symptom duration beyond the past four weeks
Frequently Asked Questions
How is the PHQ-15 scored?
Each of the 15 somatic symptom items is rated on a 3-point scale: 0 (not bothered at all), 1 (bothered a little), or 2 (bothered a lot). All item scores are summed for a total ranging from 0 to 30. Higher scores indicate greater somatic symptom burden.
What do different PHQ-15 scores mean?
Scores of 0–4 indicate minimal somatic symptoms, 5–9 indicate low severity, 10–14 indicate moderate severity, and 15 or above indicate high severity. These cutpoints were established in the original validation study by Kroenke, Spitzer, and Williams (2002) and have been replicated in multiple populations.
Is the PHQ-15 self-report or clinician-administered?
The PHQ-15 is a self-report measure designed to be completed by the patient, typically in a waiting room or clinical setting before a visit. It does not require scoring by a clinician, though clinical interpretation of results should always involve a qualified professional.
Can the PHQ-15 diagnose somatic symptom disorder?
No. The PHQ-15 is a severity screener, not a diagnostic instrument. While elevated scores are associated with greater risk of somatic symptom disorder, a diagnosis requires a comprehensive clinical evaluation. Research has examined the PHQ-15 in combination with other tools to improve detection, but no single questionnaire is sufficient for diagnosis on its own.
References
- 1.Kroenke K, Spitzer RL, Williams JB. The PHQ-15: validity of a new measure for evaluating the severity of somatic symptoms. Psychosom Med. 2002;64(2):258-266.View source
- 2.Kroenke K, Spitzer RL, Williams JB, Löwe B. The Patient Health Questionnaire Somatic, Anxiety, and Depressive Symptom Scales: a systematic review. Gen Hosp Psychiatry. 2010;32(4):345-359.View source
- 3.Toussaint A, Hüsing P, Kohlmann S, Löwe B. Detecting DSM-5 somatic symptom disorder: criterion validity of the Patient Health Questionnaire-15 (PHQ-15) and the Somatic Symptom Scale-8 (SSS-8) in combination with the Somatic Symptom Disorder - B Criteria Scale (SSD-12). Psychol Med. 2020;50(2):324-333.View source
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The PHQ-15 (Patient Health Questionnaire-15) qualifies for reimbursement under these CPT codes (US).
Last reviewed: Jun 3, 2026
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