A 38-year-old woman presents with a 6-month history of recurrent unexpected episodes of intense fear accompanied by palpitations, diaphoresis, chest tightness, derealization, and fear of dying. She reports that following these episodes, she has progressively avoided public transportation, shopping malls, and open parking lots because she fears having an episode in places where escape might be difficult or help unavailable. She now requires her husband to accompany her to all appointments and has not driven alone in 4 months. A recent cardiology evaluation was unremarkable. Which assessment approach is most appropriate for evaluating this patient's presentation?