A 36-year-old woman with MDD in sustained remission for 18 months on paroxetine 40 mg daily wishes to discontinue her antidepressant after a thorough risk-benefit discussion with her PMHNP. Five days after reducing from 40 mg to 20 mg, she reports dizziness, electric shock-like sensations in her head, irritability, nausea, and vivid dreams. She denies any return of depressed mood or anhedonia. What is the most appropriate next step?