Alzheimer Disease and Related Neurodegenerative Diseases in Elderly Patients With Schizophrenia

Abstract

SEVERAL CLINICAL studies have reported that relatively severe cognitive impairment is seen in a high proportion of elderly patients with schizophrenia who reside in long-stay psychiatric institutions.^1-6 It has also been suggested that the cognitive impairment seen in these patients is progressive⁶ and is not attributable to a lack of cooperation, attention, or motivation or to exposure to neuroleptic medications.^6-9 These observations raise questions about whether cognitive impairment represents a late outcome of schizophrenia itself or whether elderly patients with schizophrenia are more susceptible than the general population to the development of Alzheimer disease (AD) or other recognized dementing neurodegenerative diseases. Postmortem neuropathologic studies in elderly patients with schizophrenia have provided conflicting findings^9-13 about the frequency of AD or AD-related lesions. These varying findings may have resulted from several limiting factors, including a small sample size examined, a limited neuropathologic evaluation, absence of a properly age-matched control group, or reliance on archival postmortem reports.