A 55-year-old woman presents 10 months after the death of her husband from pancreatic cancer. She reports persistent daily crying, inability to accept the death, intense longing and preoccupation with her deceased husband, difficulty engaging in activities or relationships, feeling that life is meaningless, and a sense that part of herself died with him. She has lost 15 pounds, has insomnia with early morning awakening, and reports passive suicidal ideation without plan or intent. She states she cannot imagine ever feeling better. Her PHQ-9 score is 22. She meets criteria for both prolonged grief disorder and major depressive disorder. Which treatment plan is most appropriate?