A 52-year-old man with a history of Major Depressive Disorder, currently on sertraline 100 mg daily for 8 weeks, returns to the psychiatry clinic. He reports persistent depressed mood, anhedonia, and fatigue despite compliance with medication. His wife notes no improvement in his social withdrawal or irritability. Vital signs are stable, and there are no contraindications to dose escalation. What is the most appropriate next step in management?

Explanation

## Treatment-Resistant Depression: Stepwise Approach **Key Point:** Treatment resistance is defined as failure to respond to ≥2 adequate trials of antidepressants at therapeutic doses for ≥4–6 weeks. This patient has had only ONE trial (sertraline 8 weeks at 100 mg). ### Current Status Assessment - **Duration of trial:** 8 weeks (adequate, >4 weeks) - **Dose:** 100 mg sertraline (therapeutic range 50–200 mg) - **Response:** Minimal/no response - **Number of prior adequate trials:** 1 (NOT treatment-resistant yet) **High-Yield:** The standard approach to inadequate response after one adequate trial is: 1. **Optimize current medication** (increase dose within therapeutic range) 2. **Then consider switching** if no response after optimization 3. **Augmentation strategies** (lithium, T3, atypical antipsychotics) come later 4. **ECT** is reserved for severe, psychotic, or catatonic depression, or life-threatening situations ### Dose Escalation Rationale ```mermaid flowchart TD A[Inadequate response to SSRI at therapeutic dose]:::outcome A --> B{Adequate trial duration?}:::decision B -->|No, <4 weeks| C[Continue current dose]:::action B -->|Yes, ≥4 weeks| D{At maximum dose?}:::decision D -->|No| E[Increase to next therapeutic level]:::action D -->|Yes| F[Switch to different class or augment]:::action E --> G[Reassess in 2-4 weeks]:::action F --> H[Consider lithium, TCA, or SNRI]:::action ``` **Clinical Pearl:** Sertraline can be safely escalated to 150–200 mg daily. A 2-week reassessment window is too short; typically 4 weeks is recommended, but 2 weeks is acceptable for initial dose escalation given the patient's 8-week exposure. ### Why Other Options Are Premature - **Lithium augmentation** is appropriate for treatment-resistant depression (≥2 failed trials), not first-line inadequate response - **TCA switching** skips the optimization step; SSRIs are first-line - **ECT** is not indicated without severe features (psychosis, catatonia, imminent suicide risk) [cite:Harrison 21e Ch 470; CANMAT Guidelines 2016]