A 24-year-old Taiwanese man was admitted for psychiatric inpatient treatment because of major depressive disorder. The patient presented the characteristic symptoms of depressed mood, loss of interest, fatigue, insomnia with vivid nightmares, and feelings of hopelessness for 3 months. He especially complained of easily broken sleep due to nightmares. Initial laboratory blood tests, such as thyroid function, revealed normal ranges. The 17-item Hamilton Rating Scale for Depression (Ham-D) total score was 16 on the first hospital day. Initially, the patient was treated with escitalopram, 10 mg/day, for 14 days. Depressed mood was improved, and the Ham-D total score improved to 9. However, the symptoms of easily broken sleep with vivid nightmares persisted; 50 mg of trazodone per night was then added, and insomnia with vivid nightmares remitted during the following nights. However, he also experienced dizziness, headache, and nausea. Because of the intolerable side effects, trazodone was discontinued, and zolpidem, 10 mg per night, was added. Unfortunately, the nightmares returned when trazodone was discontinued.