A 32-year-old woman presents to your clinic with a 6-month history of excessive, uncontrollable worry about her work performance and family responsibilities. She reports difficulty sleeping, muscle tension, and irritability. She has no history of panic attacks or phobias. Her vital signs are normal, and physical examination is unremarkable. She has a remote history of alcohol misuse but has been abstinent for 3 years. She is concerned about medication dependence. Which of the following is the most appropriate long-term pharmacologic management for her condition?