A 38-year-old woman with bipolar disorder has been stable on lithium for the past 2 years. She comes to her psychiatrist's office in tears after a 2-week history of a depressed mood, poor concentration, loss of appetite, and passive suicidal ideation. Which of the following steps should the psychiatrist take next?
Sta the patient on a second mood stabilizer Sta the patient on a long-acting benzodiazepine Stop the lithium and sta an antidepressant Sta an antidepressant and continue the lithium