Cognitive decline in late-life schizophrenia: a longitudinal study of geriatric chronically hospitalized patients.

BACKGROUND: Geriatric schizophrenic patients with a chronic course of institutionalization manifest cognitive and functional impairments that implicate decline at some time point after the onset of illness. The rate of change in cognitive and functional status in these patients has not yet been identified with a longitudinal study.
METHODS: Three hundred and twenty-six schizophrenic patients entered a 30-month follow-up study with two separate assessments of the patients. Overall functional and cognitive status was indexed with the Clinical Dementia Rating (CDR). Survival analysis was used to examine changes in cognitive and functional status, including worsening for the less impaired patients and improvements on the part of more impaired patients.
RESULTS: Approximately 30% of the patients who had baseline scores in the less impaired range manifested a worsening of their CDR ratings to a score of 2.0 (moderate) or more severe, whereas only 7% of the sample with lower scores at baseline appeared to improve in their functioning. Several characteristics of the patients at baseline assessment predicted increased risk for cognitive and functional decline, including lower levels of education, older age, and more severe positive symptoms.
CONCLUSIONS: Cognitive and functional decline can be detected in a short-term follow-up in a subset of geriatric long-stay patients with schizophrenia. This decline appears distributed across patients and not due to the presence of progressive degenerative dementing conditions. Later research will have to identify the causes of this decline, possibly on the basis of the risk factors identified in this study.