Postpartum Depression - Priority Nursing Intervention

A 28-year-old female, G3 T1 P1 A1 L1, is in the immediate postpartum period following the vaginal delivery of a healthy infant. During her assessment, the nurse notes that the patient expresses feelings of sadness and emotional instability. She also mentions difficulty sleeping and a lack of interest in activities she usually enjoys. The nurse recognizes that this may indicate a significant psychological concern related to postpartum adjustment. Which nursing intervention should the nurse prioritize in this patient's care plan?