A 33-year-old woman has been treated for major depression for 2 years with escitalopram (Lexapro) 20 mg. She presents to your office with flu-like symptoms, dizziness, nausea, and "brain zaps." She reports she ran out of her medication and forgot to get it refilled. What is the most likely diagnosis?
Explanation & Rationale
Choice A reason: Serotonin syndrome results from excessive serotonergic activity, often due to drug interactions or overdose. It presents with hyperreflexia, agitation, and autonomic instability, not flu-like symptoms or brain zaps. Choice B reason: Serotonin discontinuation syndrome occurs when SSRIs like escitalopram are abruptly stopped. Symptoms include dizziness, nausea, fatigue, flu-like symptoms, and brain zaps. This syndrome is common with short half-life SSRIs and matches the patient’s presentation. Choice C reason: Extrapyramidal symptoms are motor-related side effects of antipsychotics, including tremors, rigidity, and dystonia. They are unrelated to SSRI discontinuation. Choice D reason: Neuroleptic malignant syndrome is a life-threatening reaction to antipsychotics, characterized by muscle rigidity, fever, and autonomic instability. It does not occur with SSRI withdrawal.