Cognitive impairment and enduring negative symptoms: a comparative study of geriatric and nongeriatric schizophrenia patients.

Chronically institutionalized geriatric (n = 174; average length of hospitalization = 35.1 years) and nongeriatric (n = 59; average length of hospitalization = 17.3 years) schizophrenia patients were classified with regard to their enduring negative symptoms (ENS) over a year. All patients completed neuropsychological tests that have been previously found to be implicated in geriatric schizophrenia: the Mini-Mental State Examination (MMSE), the Modified Boston Naming Test, Constructional Praxis, and Word List Learning and Delayed Recall. With MMSE scores used as covariates, ENS status and age group effects were examined on the cognitive measures at the second assessment. Results indicated that there was considerable specificity of cognitive impairment in the ENS syndrome even in patients with a chronic course of unremitting illness. Furthermore, when specific cognitive measures were examined and global impairment statistically controlled for, patients with ENS manifested a distinct pattern of impairment, rather than uniformly inferior performance. In particular, patients with ENS performed more poorly on tests putatively sensitive to frontal and parietal lobe functions, replicating earlier results on younger patients with a much better overall functional outcome. These data suggest that ENS defines a distinct subgroup of patients that can be identified even against the backdrop of chronic institutionalization.