“Mrs. L” is a 58-year-old, female, first-episode, drug-naïve PD patient with the following panic symptoms for 6 months: unexplained abdominal pain, gastrointestinal upset, dyspepsia, chest tightness, palpitations, dizziness, and limb numbness. These symptoms occurred suddenly and exacerbated progressively within 10 minutes. She had significant anticipatory worry about additional attacks, and these attacks had already caused significant disturbances of her social and occupational role. She received many kinds of physical or laboratory examinations, such as electrocardiogram, chest X-ray, computed tomography of chest, and magnetic resonance imaging of brain and spine, but all these examinations failed to find any medical reason for these somatic symptoms. She also refused to take antidepressant or benzodiazepine treatment for fear of side effects and only received nonpharmacologic treatment. After signing informed consent, she started to take sodium benzoate (SB) for her panic symptoms. No concurrent psychotherapies were performed in this patient during SB treatment. After 2 weeks of SB, she had mild improvement of PD (PDSS score: 18 → 13), with less severity of abdominal discomforts, chest tightness, palpitations, and anticipatory anxiety. However, during the first 2 weeks, she still had limb numbness, dizziness, and headache. At the 6th week, she experienced subsequent response in PD symptoms (PDSS score: 13 → 7). She also had less dizziness, less anticipatory anxiety, and more improvement in abdominal discomfort, chest tightness, and palpitations. Residual PD symptoms, such as limb numbness and headache, were still noted in the 6th week. No significant side effects of SB treatment during this 6-week period were mentioned.