A 32-year-old woman presents to the psychiatry outpatient clinic with a 6-month history of recurrent, unexpected panic attacks characterized by palpitations, dyspnea, chest discomfort, and fear of dying. She reports 4 attacks in the past month, each lasting 20–30 minutes. Between attacks, she worries constantly about having another one and has begun avoiding crowded places and public transport. Physical examination and cardiac workup (ECG, troponin, echocardiography) are normal. She denies substance use or medical comorbidities. What is the most appropriate next step in management?