A 27-year-old male with a single episode of psychosis 18 months ago was maintained on olanzapine 10 mg daily with full symptom resolution for 14 months. After shared decision-making, a gradual taper was initiated over eight weeks, and olanzapine was discontinued four weeks ago. He now presents with his mother, who reports he has become increasingly suspicious of neighbors, believes his phone is being monitored, and has been sleeping only 3-4 hours per night for the past week. His BPRS score is 42. He was adherent to the taper schedule and had no substance use during this period. The PMHNP is evaluating whether this represents a relapse of the underlying psychotic disorder or supersensitivity psychosis related to discontinuation. Which of the following best represents the appropriate evaluation?