B-101: Differential Diagnosis of Psychosis in Older Adults

Abstract

Objective: Older adults presenting with psychotic symptoms create diagnostic challenges given numerous etiologies including metabolic, infectious, medication toxicity, or neurocognitive disorders. Very late onset psychosis (VLOP), defined as psychosis first occurring after age 60, is particularly difficult to identify in the Emergency Department (ED) without collateral information or prior psychiatric history, risking misattribution of symptoms. Method/Data Selection: A 67-year-old female with a history of major depressive disorder (MDD), generalized anxiety disorder (GAD), and sexual trauma, with two prior psychiatric hospitalizations was involuntarily admitted after experiencing auditory hallucinations and delusions (i.e., calling herself the “Seroquel lady”). She underwent a comprehensive medical evaluation, a cognitive screener (MMSE), and head CT scan that were unremarkable. Results/Data Synthesis: Internal medicine referred the patient to neuropsychology for diagnostic clarification. Bedside evaluation revealed a generally alert and oriented patient who engaged adequately, though nursing staff noted apparent "multiple personalities," irritability, and guardedness. She would revert to a childlike voice, which she described being a young girl. Given her presentation, the MMPI-3 was administered rather than additional cognitive measures. Validity scales rendered the MMPI-3 uninterpretable; clinical scales were largely unremarkable. Conclusions: Stable cognitive functioning argued against delirium. Prevalence of psychosis in the elderly with dementia varies by etiology. Her MMSE of 29/30 with intact attention and relatively preserved recall made Lewy Body Dementia and moderate-to-severe Alzheimer's disease unlikely. The overall presentation was most consistent with VLOP, subsequently confirmed on the inpatient psychiatric unit. The patient responded well to medications and was discharged to a board of care for continued treatment.