What is the recommended evaluation and treatment for patients screening positive for depression using the Patient Health Questionnaire 9 (PHQ9) or Patient Health Questionnaire 2 (PHQ2)?

PHQ-9 and PHQ-2 Screening and Management Protocol

For patients screening positive on PHQ-2 or PHQ-9, a structured evaluation and treatment approach based on score severity should be implemented, with immediate referral to mental health specialists for those with moderate-to-severe symptoms or suicidal ideation. 1

Screening Process

• The PHQ-2 screens for the two core symptoms of depression: anhedonia and depressed mood, with each item scored 0-3 based on symptom frequency over the past two weeks 2
• If either PHQ-2 item scores ≥2 (symptoms present more than half the days), administer the full PHQ-9 for comprehensive assessment 3
• The PHQ-9 includes all nine DSM criteria for depression with scores ranging from 0-27 4
• While the traditional PHQ-9 cutoff is ≥10, a cutoff of ≥8 is recommended by some guidelines based on diagnostic accuracy studies 3, 1

Interpretation of PHQ-9 Scores

None/Mild Symptomatology (PHQ-9 score 1-7)

• Provide education about depression and normal stress responses 1
• Ensure patient has adequate coping skills and social support 3
• Consider reassessment at future visits 1

Moderate Symptomatology (PHQ-9 score 8-14)

• Evaluate for pertinent history and specific risk factors for depression 3
• Consider referral to psychology or psychiatry for diagnostic evaluation 3
• Offer low-intensity intervention options (e.g., psychoeducation, self-help resources) 3
• Schedule follow-up to monitor symptoms 1

Moderate-to-Severe/Severe Symptomatology (PHQ-9 score 15-27)

• Refer immediately to psychology and/or psychiatry for diagnosis and treatment 3
• Assess for risk of harm to self or others 3
• Evaluate for medical or substance-induced causes of depressive symptoms 1

Special Attention to Self-Harm Risk

• Pay particular attention to item 9 of the PHQ-9, which assesses thoughts of self-harm 3
• For patients endorsing any frequency of self-harm thoughts, conduct a thorough risk assessment including frequency, intensity, and presence of plan or intent 5
• If imminent risk is identified, immediate referral for emergency evaluation by a licensed mental health professional is required 3, 5
• Implement safety measures including one-to-one observation if necessary, and restrict access to potential means of self-harm 5

Important Clinical Considerations

• The PHQ-9 has high sensitivity (88%) and specificity (88%) for detecting major depression when using a cutoff score of ≥10 4
• The PHQ-2 has comparable sensitivity (83%) but lower specificity (92%) compared to PHQ-9, making it an excellent initial screening tool 2
• The PHQ-9 is valid for measuring changes in depression severity over time, making it useful for monitoring treatment response 6
• Some clinicians may consider omitting the self-harm item from the PHQ-9, but this artificially lowers scores and weakens predictive validity 3
• Consider cultural sensitivity in assessment and treatment planning, and tailor assessment for patients with learning disabilities or cognitive impairments 3

Common Pitfalls to Avoid

• Do not rely solely on PHQ-9 scores for diagnosis; clinical interview remains essential to confirm depression diagnosis 7, 8
• Do not dismiss self-harm thoughts in older adults, as this population may be at higher risk for completed suicide 5
• Avoid assuming that absence of a specific plan means low risk; continue thorough assessment and monitoring of all patients with self-harm thoughts 5
• Do not fail to implement adequate follow-up systems after screening; screening without appropriate follow-up pathways is ineffective 8