A 40-year-old female with recurrent major depressive disorder and comorbid avoidant personality traits has been receiving interpersonal therapy (IPT) for 16 sessions over five months. Her PHQ-9 has fluctuated between 13 and 16 throughout treatment with no sustained improvement from her baseline of 15. She attends sessions consistently and is engaged in the therapeutic process, but she continues to endorse persistent feelings of inadequacy, avoidance of social relationships due to fear of rejection, and rigid self-critical thought patterns. The therapist notes that while the patient has gained insight into her interpersonal patterns, she has difficulty translating this insight into behavioral change. Her interpersonal functioning has not measurably improved based on the Inventory of Interpersonal Problems (IIP) scores. The PMHNP is evaluating psychotherapy treatment progress and considering whether a modality change is indicated. Which evaluation is most appropriate?