In the first week, the initial dose of olanzapine was 5 to 10 mg/d. In the second week, the dosage was adjusted according to the disease condition and patient’s tolerance, and the maximum dose is 20 mg/d. The course of treatment was 8 weeks. After oral olanzapine tablets, when the blood concentration reached a steady state, 2 mL of blood was collected intravenously at 1, 2, and 3 weeks of treatment, respectively, in the morning before taking medicine on an empty stomach, placed in an anticoagulant tube, centrifuged at 3000 r·min−1 for 5 minutes, and the separated serum was stored in a refrigerator at 4°C for use. The plasma concentration was monitored by ultra-performance liquid chromatography-tandem mass spectrometry. The dose corrected plasma concentration in this study = plasma concentration/total dose.