A 32-year-old woman presents to the psychiatry clinic with a 6-month history of recurrent, unexpected panic attacks characterized by palpitations, dyspnea, chest discomfort, and fear of dying. She has developed anticipatory anxiety and avoids public places and crowded settings. 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?