How would you diagnose and treat a 39-year-old female with depression, poor motivation, concentration difficulties, slight weight gain, and sleep disturbances?

Diagnosis and Treatment of Major Depressive Disorder in a 39-Year-Old Female

Diagnostic Assessment

This patient meets criteria for Major Depressive Disorder (MDD) based on the presence of at least 5 diagnostic symptoms over the past month, including depressed mood, poor motivation (anhedonia), concentration difficulties, weight gain, and early morning awakening. 1

Confirm Diagnostic Criteria

The diagnosis requires at least 5 of the following symptoms present during a 2-week period, with at least one being depressed mood or loss of interest/pleasure 2, 1:

• Depressed mood - Present in this patient 1
• Markedly diminished interest or pleasure (anhedonia) - Present as "poor motivation" 1, 3
• Significant weight change or appetite disturbance - Present as "slight weight gain" 2, 1
• Insomnia or hypersomnia - Present as "difficulty sleeping with early waking" 2, 1
• Psychomotor agitation or retardation - Needs assessment 2
• Fatigue or loss of energy - Likely present given poor motivation 2, 1
• Diminished ability to concentrate - Present 2, 1, 3
• Feelings of worthlessness or excessive guilt - Needs assessment 2
• Recurrent thoughts of death or suicidal ideation - Must be assessed immediately 2, 1

Critical Safety Assessment

Evaluate for suicidal ideation, intent, and plan immediately, as this is both a diagnostic criterion and has critical safety implications. 2, 1 Ask directly about recurrent thoughts of death, suicidal ideation, suicide attempts, or specific plans to commit suicide 2.

Rule Out Other Conditions

Before confirming MDD, exclude 1:

• Bipolar disorder - Screen for history of manic or hypomanic episodes (elevated mood, decreased need for sleep, racing thoughts, excessive energy, reckless behavior) 2
• Substance-induced mood disorder - Assess for alcohol, drug use, or medications that could cause depressive symptoms 2, 1
• Medical conditions - Consider thyroid dysfunction (obtain TSH), anemia, vitamin deficiencies, or other medical causes of fatigue and mood changes 2
• Adjustment disorder - This diagnosis is excluded because symptoms have persisted for one month without resolution and no clear identifiable stressor is mentioned 1

Treatment Approach

First-Line Pharmacotherapy

Initiate treatment with a second-generation antidepressant (SSRI or SNRI) as first-line therapy, with sertraline being an appropriate choice given its efficacy, tolerability profile, and low drug interaction potential. 4, 5

Medication Selection Rationale

• All second-generation antidepressants have equivalent efficacy for treating depression 4, 6
• Selection should be based on side effect profiles, cost, patient preferences, and comorbidities 4, 7
• Sertraline 50-200 mg/day is FDA-approved for major depressive disorder and has well-established efficacy 5, 8, 9
• Sertraline has a low potential for drug interactions at the cytochrome P450 level, making it safer in patients who may require multiple medications 8, 9

Specific Dosing and Monitoring

• Start sertraline 50 mg daily, taken with or without food 5
• Assess patient status, therapeutic response, and adverse effects within 1-2 weeks of initiation 4
• Monitor closely for suicidal ideation, particularly in the first 1-2 months of treatment 4, 5
• If inadequate response after 6-8 weeks at therapeutic dose, modify treatment 4
• Titrate dose as needed up to 200 mg/day based on response and tolerability 5, 8

Common Side Effects to Discuss

Warn the patient about potential adverse effects including dry mouth, headache, diarrhea, nausea, insomnia, somnolence, dizziness, and sweating 5, 8, 9. Sexual dysfunction is common with SSRIs; if this becomes problematic, consider switching to bupropion which has lower rates of sexual adverse events 4.

Psychotherapy

Combine antidepressant medication with evidence-based psychotherapy, as combined treatment is superior to either modality alone. 6

Effective psychotherapy options include 6:

• Cognitive behavioral therapy (CBT)
• Behavioral activation
• Problem-solving therapy
• Interpersonal therapy
• Brief psychodynamic therapy
• Mindfulness-based psychotherapy

Combined treatment shows greater symptom improvement than psychotherapy alone (SMD 0.30) or medication alone (SMD 0.33) 6.

Treatment Duration

• Continue treatment for 4-9 months after satisfactory response for a first episode 4
• For patients with recurrent episodes, longer duration therapy is beneficial 4
• The efficacy of sertraline in maintaining antidepressant response has been demonstrated for up to 52 weeks 5

Follow-Up and Monitoring

Implement systematic follow-up with outcome assessment using validated tools such as the PHQ-9, as collaborative care programs significantly improve treatment effectiveness (SMD 0.42). 3, 6

Monitor for 4, 5:

• Therapeutic response and symptom improvement
• Suicidal ideation (especially early in treatment)
• Emergence of manic symptoms
• Adverse effects including bleeding risk, hyponatremia, serotonin syndrome
• Treatment adherence

Second-Line Options if Initial Treatment Fails

If the patient does not respond adequately to initial SSRI therapy after 6-8 weeks at therapeutic dose, options include 6:

• Switching to a different antidepressant
• Adding a second antidepressant
• Augmenting with a non-antidepressant medication (e.g., atypical antipsychotic)

These strategies have approximately equal likelihood of success 6.

Critical Safety Warnings

Do not abruptly discontinue sertraline, as this can cause withdrawal symptoms including anxiety, irritability, mood changes, restlessness, sleep disturbances, headache, sweating, nausea, dizziness, and electric shock-like sensations. 5 When discontinuation is appropriate, taper gradually while providing concurrent cognitive behavioral therapy to decrease risk of relapse 7.