A 40-year-old woman with no previous psychiatric history seeks help from her internist for a sleep problem. Initially, she is able to fall asleep but then sleeps fitfully, and finally around 4:00 a.m. decides to stay up. She averages approximately 34 hours of sleep per night, and this has been occurring for the last 3 weeks. She finds herself quite tired and "blue" during the day but is unable to nap. Mornings are "the worst" for her, but she feels better toward the end of the day. There has been a 15-lb weight loss because "I'm just not hungry." She denies any physical problems except for constipation. As a gradeschool teacher, she feels extremely stressed but sees no way out and no way to improve the situation. At times, suicide seems like a possible option, and she admits to spending long hours brooding on how to do it. A physical examination is unremarkable.
Which of the following is the most appropriate treatment choice?