What is the appropriate assessment and initial management for a patient presenting with depressed mood?

Assessment and Initial Management of Low Mood

For a patient presenting with low mood, immediately assess for suicidal ideation and self-harm risk first, then use the PHQ-9 screening tool with a cutoff score of ≥8 to identify depression, followed by ruling out medical causes before initiating treatment with either psychotherapy or antidepressant medication based on severity. 1

Immediate Safety Assessment

Before anything else, directly ask about thoughts of self-harm or suicide. If the patient endorses any risk of harm to self or others:

• Refer immediately to emergency psychiatric services 1
• Arrange one-to-one observation and ensure a safe environment
• Do not proceed with outpatient management until safety is established

Structured Screening Approach

Use a phased assessment rather than relying on symptom count alone 1:

Step 1: Two-Question Screen

Ask about the core symptoms over the past 2 weeks:

• Depressed mood most of the day
• Loss of interest or pleasure in activities (anhedonia)

If either is present more than half the time or nearly every day, proceed to Step 2.

Step 2: Complete PHQ-9

Use a cutoff score of ≥8 (not the traditional 10) to identify clinically significant depression 1. This lower threshold improves sensitivity in detecting depression requiring intervention.

The PHQ-9 assesses:

• Depressed mood
• Anhedonia
• Sleep disturbance
• Fatigue
• Appetite changes
• Feelings of worthlessness/guilt
• Concentration problems
• Psychomotor changes
• Suicidal thoughts

Step 3: Assess Severity and Risk Factors

Determine:

• Duration of symptoms (must be ≥2 weeks for major depression)
• Functional impairment in work, relationships, or daily activities
• Prior psychiatric history and treatment response
• Comorbid anxiety (present in 50-60% of depression cases) 1
• Substance use
• Family history of bipolar disorder (critical to avoid triggering mania with antidepressants)

Rule Out Medical Causes

Before diagnosing primary depression, exclude or treat:

• Uncontrolled pain or fatigue
• Thyroid dysfunction (check TSH)
• Electrolyte imbalances
• Infection or delirium
• Medication side effects (corticosteroids, beta-blockers, etc.)
• Substance withdrawal

1

Initial Treatment Selection

Treatment choice depends on severity and patient preference, with combination therapy superior to monotherapy for moderate-to-severe depression 2.

For Mild Depression (PHQ-9: 8-13)

Choose ONE of:

• Psychotherapy alone (cognitive behavioral therapy, behavioral activation, problem-solving therapy, interpersonal therapy, brief psychodynamic therapy, or mindfulness-based therapy) 2
• Bright light therapy (10,000 lux for 30 minutes daily, regardless of seasonal pattern) 3
• Antidepressant medication if patient prefers or psychotherapy unavailable

For Moderate Depression (PHQ-9: 14-18)

Recommend combination therapy:

• Antidepressant medication PLUS psychotherapy (provides 0.30-0.33 standardized mean difference improvement over monotherapy) 2

For Severe Depression (PHQ-9: ≥19)

Initiate combination therapy immediately:

• High-intensity SSRI or SNRI
• PLUS structured psychotherapy
• Consider psychiatry referral

Antidepressant Selection

No single antidepressant is superior to others 1. Choose based on:

• Side effect profile (e.g., avoid sedating agents if fatigue predominates)
• Drug interactions with current medications
• Prior treatment response (if applicable)
• Patient preference

Common first-line options include SSRIs (sertraline, escitalopram) or SNRIs (duloxetine, venlafaxine). All show small-to-medium effect sizes over placebo (SMD 0.23-0.48) 2.

Patient Education and Support

Provide specific information about:

• Expected timeline for improvement (typically 4-8 weeks)
• Potential side effects and when to call
• Warning signs requiring immediate contact (worsening suicidal thoughts, severe agitation)
• Importance of medication adherence even when feeling better
• Educate family members as well 1

Follow-Up Schedule

Monitor biweekly or monthly until symptom remission 1:

• Assess medication adherence and side effects
• Assess psychotherapy attendance and satisfaction
• Re-administer PHQ-9 to track progress
• If no improvement after 8 weeks despite good adherence: change antidepressant, add second agent, or augment with non-antidepressant medication 1

Critical Pitfalls to Avoid

• Missing comorbid anxiety: Treat depression first when both are present 1
• Overlooking bipolar risk: Family history of bipolar disorder requires psychiatry consultation before starting antidepressants 4
• Inadequate suicide assessment: Directly ask about suicidal ideation at every visit
• Premature discontinuation: Many patients lack motivation to follow through with referrals or medication—proactively address barriers 1
• Ignoring medical causes: Always rule out thyroid disease, pain, and delirium before attributing symptoms to primary depression