A 67-year-old woman with severe major depressive disorder with psychotic features has been hospitalized for three weeks. She presents with profound psychomotor retardation, delusional guilt, refusal to eat or drink, and a 15-pound weight loss over the past month. She has become virtually mute and is now requiring IV fluids for hydration. She has failed adequate trials of two different antidepressant-antipsychotic combinations during this admission, with no meaningful clinical improvement. Her medical history includes well-controlled hypertension and hypothyroidism. She has no history of seizure disorder, and a recent brain MRI was unremarkable. Her family, who holds medical power of attorney, requests discussion of all treatment options. The PMHNP is considering electroconvulsive therapy as part of the treatment plan. Which of the following best describes the rationale for including ECT in this patient's treatment plan?