At what PHQ‑9 score should a patient be referred for mental‑health evaluation?

PHQ-9 Referral Thresholds for Mental Health Evaluation

Refer patients to mental health professionals when the PHQ-9 score is ≥8 for moderate symptoms (scores 8-14) or immediately for moderate-to-severe/severe symptoms (scores ≥15), with emergency psychiatric evaluation required for any endorsement of self-harm thoughts regardless of total score. 1

Algorithmic Approach to PHQ-9-Based Referral

Score-Based Referral Thresholds

Scores 1-7 (None/Mild):

• No mental health referral is needed for scores in this range 1, 2
• Provide patient education about depression and normal stress responses 2
• Ensure adequate coping skills and access to social support systems 2
• Schedule reassessment at 3,6, and 12 months or during times of personal transition 1, 2

Scores 8-14 (Moderate):

• Make referral to psychology or psychiatry for diagnostic determination 1
• These patients have most depressive symptoms with mild to moderate functional impairment 1
• The recommended cutoff of ≥8 is based on diagnostic accuracy studies in cancer outpatients and supported by meta-analysis 1, 3
• This represents a lower threshold than the traditional cutoff of ≥10, improving sensitivity for detecting major depressive disorder 1, 3

Scores 15-19 (Moderate-to-Severe) and 20-27 (Severe):

• Make immediate referral to psychology and/or psychiatry for diagnosis and treatment 1
• These patients have the majority of depressive symptoms with moderate to marked functional interference 1
• Contact the psychiatric service directly rather than scheduling a routine future appointment 4
• This is mandatory specialist-level care due to severity and functional impairment 4

Critical Safety Override: Item 9 Assessment

Regardless of total PHQ-9 score, emergency psychiatric evaluation is required if:

• The patient endorses any frequency of thoughts about being better off dead or hurting themselves on PHQ-9 item 9 1, 4, 2
• This represents acute suicide risk requiring immediate specialist assessment 4
• Facilitate a safe environment by removing means of self-harm and establishing one-to-one observation until psychiatric evaluation is completed 1, 4
• A patient can have a low total score (even 7) but still endorse suicidal ideation requiring immediate intervention 2

Understanding the Cutoff Score Rationale

The panel's recommended cutoff of ≥8 differs from the traditional ≥10 threshold for important reasons:

• A meta-analysis demonstrated acceptable diagnostic properties for cutoff scores between 8 and 11, with no substantial differences in pooled sensitivity and specificity across this range 3
• The ≥8 cutoff improves sensitivity in cancer outpatients specifically 1
• Pooled sensitivity at cutoff 10 is 88% with specificity of 88% for major depression, but lowering to 8 captures more true cases 5, 6
• The diagnostic odds ratio remains strong across the 8-11 range 3

Risk Factors That Lower the Threshold for Referral

Even with moderate scores (8-14), immediate referral to psychiatry is warranted if the patient has: 1

• History of prior mood disorder with or without prior treatment 1
• Comorbid mood and/or anxiety disorders (e.g., generalized anxiety disorder) 1
• Prior or current substance use 1
• Recurrent, advanced, or progressive disease 1
• Social isolation (single, not married, widowed, divorced) 1
• Unemployment with low financial resources 1
• Lower education level (less than high school/GED) 1

Common Pitfalls to Avoid

Never rely solely on the total PHQ-9 score without checking item 9: 4, 2

• Some clinicians omit item 9 about self-harm, which artificially lowers the score and weakens predictive validity 1
• Patients may endorse suicidal ideation even with low total scores 2
• Always conduct a thorough clinical interview beyond the screening tool 4

Do not delay referral for scores ≥15: 4

• These patients require urgent, not routine, psychiatric consultation 4
• The combination of severe symptoms and functional impairment mandates specialist-level care 4

Avoid assuming scores 1-7 are always benign: 2

• While formal treatment is not indicated, reassessment is essential 2
• If repeat screening shows progression to ≥8, the management approach changes significantly 2

Documentation Requirements

• Record the specific response to PHQ-9 item 9 4
• Document safety assessment findings and interventions implemented 4
• Note the psychiatric referral with expected timeframe 4
• Record the patient's access to lethal means and any means restriction counseling provided 4