A 38-year-old female with major depressive disorder and comorbid generalized anxiety disorder has been on sertraline 200 mg daily for 12 weeks. Her depression has improved substantially, but she reports persistent daily worry and muscle tension. The PMHNP adds buspirone 10 mg twice daily for anxiety augmentation. At her 1-week follow-up, the patient reports no improvement in anxiety and wants to stop the buspirone. Which of the following is the most appropriate response?