A 26-year-old woman presents with low mood, anhedonia, fatigue, poor concentration, and feelings of worthlessness for the past 6 weeks. She has lost interest in her job and has difficulty sleeping. She denies suicidal thoughts. What is the most appropriate first-line treatment? A) Cognitive behavioral therapy (CBT) B) Fluoxetine C) Mirtazapine D) Electroconvulsive therapy (ECT) E) Diazepam Correct Answer: B) Fluoxetine Explanation: This patient has moderate depression, characterized by persistent low mood, anhedonia, and functional impairment for more than 2 weeks. Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine are first-line pharmacological treatment. A) CBT → Incorrect. CBT is first-line for mild depression or used alongside medication for moderate-to-severe cases. C) Mirtazapine → Incorrect. Mirtazapine is useful for patients with insomnia or weight loss, but SSRIs are first-line. D) ECT → Incorrect. ECT is reserved for severe depression with psychotic features or treatment resistance. E) Diazepam → Incorrect. Diazepam is a benzodiazepine used for anxiety disorders, not depression. Key Tips for PLAB 1: ✅ Mild depression → First-line is CBT. ✅ Moderate to severe depression → First-line is SSRIs (fluoxetine, sertraline, citalopram). ✅ Severe depression with suicidal ideation or psychosis → Consider ECT.
