Background: Vortioxetine, known for its efficacy in treating depression through its effects on various neurotransmitters, has not been previously reported to induce syndrome of inappropriate secretion of antidiuretic hormone (SIADH).
Case Presentation: This case report describes a 74-year-old man with major depressive disorder who developed SIADH 1 week after starting treatment with vortioxetine. SIADH is characterized by symptoms such as headache, nausea, disorientation, and seizures, stemming from hyponatremia (123 mEq/L), without dehydration or edema.