Antidepressants — SSRIs, SNRIs, TCAs

Which of the following tricyclic antidepressants has the LEAST anticholinergic side effects?

A 48-year-old man with treatment-resistant depression has been switched from fluoxetine to venlafaxine XR 225 mg daily. After 3 weeks, he develops severe headache, neck stiffness, tremor, hyperreflexia, and agitation. His core temperature is 38.5°C. He admits to taking an herbal supplement containing St. John's wort for 2 weeks alongside the venlafaxine. What is the most likely diagnosis and the primary mechanism of toxicity?

A 38-year-old woman with major depressive disorder is started on sertraline 50 mg daily. After 3 weeks, she reports persistent depressive symptoms with no improvement. Her psychiatrist suspects sertraline non-response and wants to confirm adequate drug exposure before switching to another agent. Which investigation is most appropriate to guide the next therapeutic decision?

Among the selective serotonin reuptake inhibitors (SSRIs), which is the most common cause of sexual dysfunction in both male and female patients?

A 42-year-old woman with major depressive disorder has been on sertraline 100 mg daily for 6 weeks. She reports persistent depressive symptoms with no improvement. She denies suicidal ideation, and tolerates the medication well without adverse effects. What is the most appropriate next step in management?