A 74-year-old woman is referred to the psychiatric clinic by her primary care provider for evaluation of a six-month history of progressive low mood, anhedonia, poor appetite with a 12-pound weight loss, insomnia with early morning awakening, and difficulty concentrating. Her family reports that she has also been having trouble remembering appointments, misplacing items, and repeating questions. She retired from teaching three years ago and has become increasingly isolated since her husband passed away 18 months ago. Her medical history includes hypertension controlled with lisinopril and hypothyroidism managed with levothyroxine. Her most recent TSH level was within normal range. She scores 18 out of 30 on the Montreal Cognitive Assessment (MoCA) and 12 on the Patient Health Questionnaire-9 (PHQ-9). The PMHNP must determine the most appropriate next step.