The Convergence of Neuropsychological Testing and Clinical Ratings of Cognitive Impairment in Patients With Schizophrenia Philip D. Harvey, Mark R. Serper, Leonard White, Michael J. Parrella, Susan R. McGurk, Patrick J. Moriarty, Christopher Bowie, Nehal Vadhan, Joseph Friedman, and Kenneth L. Davis This study examined the relationship between clinical rating of cognitive symptoms and performance on neuropsychological tests in acute and chronic sam- ples of patients with schizophrenia. Two separate studies examined patients who varied widely in their lifetime functional outcome, including 263 elderly poor-outcome inpatients and 20 acutely admitted pa- tients. In the first study, six cognitive performance measures were collected, and in the second study, five different measures were collected. Correlations with different symptom models of cognitive and neg- ative symptoms were examined. In both samples, cognitive symptoms were never more highly corre- lated with cognitive test performance than with neg- ative symptoms. When cognitive and negative symp- tom ratings were combined, they never accounted for as much as half of the variance in performance on the cognitive tests in both samples. These data suggest that clinical assessment of symptoms is not a viable alternative to neuropsychological testing to obtain information about cognitive functioning in schizo- phrenia. These results may also be specific to the clinical rating scale used, the Positive and Negative Syndrome Scale (PANSS). Copyright © 2001 by W.B. Saunders Company C OGNITIVE IMPAIRMENT has been recog- nized since the earliest descriptions of schizophrenia. Recently, however, the functional importance of cognitive impairments has been in- creasingly appreciated. Cognitive impairment is a major contributor to poor functional outcome. 1,2 Notable deficits occur in multiple aspects of cog- nitive functioning, including memory, attention, verbal fluency, and executive and visual-motor skills, 3 with these deficits being moderately corre- lated with each other. Although the extent of per- formance deficits may vary across tests, most schizophrenic patients have impairments in multi- ple domains of cognitive functioning. Many stud- ies have examined the relationship of cognitive impairment to the various symptoms of schizo- phrenia, with the most common finding indicating significant correlations between cognitive impair- ment and negative symptoms, 4 as well as func- tional deficits. 5 Cognitive deficits are also more severe in patients with a poorer lifetime functional outcome, 1 and are related to poorer response to conventional neuroleptic treatment, 6,7 suggesting both global and specific relationships between cog- nitive and symptomatic and cognitive and func- tional deficits in schizophrenia. In addition, cogni- tive impairment is not necessarily stable over time, with considerable evidence that deficits at the time of the first episode are greater than during the premorbid period. 8 In all of these studies examining the relationship between cognitive deficit and other aspects of the illness, performance-based cognitive tests have been employed. The results of these studies have been relatively consistent in their support of neu- ropsychological assessment as a mechanism to identify the correlates of functional deficits. These findings are consistent with earlier research that indicated that impaired performance on neuropsy- chological tests predicted functional capacity across different neuropsychiatric conditions. 9 The recent increase in interest in cognitive func- tioning in schizophrenia has led to the suggestion that behavioral manifestations of cognitive impair- ment can be effectively measured with clinical ratings. If feasible and valid, clinical ratings of cognitive impairment would be collected more quickly than performance-based testing measures and would be more broadly available to mental health professionals. The specific items identified as cognitive symptoms, suitable for clinical rating, differ across previous studies, largely because ex- From the Mount Sinai School of Medicine; Hofstra Univer- sity; and the New York University School of Medicine, New York, NY. Supported by the assessment core (Philip D. Harvey, PI) of the Mt. Sinai Mental Health Clinical Research Center (Kenneth L. Davis, PI), and the VISN 3 MIRECC from Department of Veterans Affairs. Address reprint requests to Philip D. Harvey, Ph.D., Depart- ment of Psychiatry, Box 1229, Mt. Sinai School of Medicine, New York, NY 10029. Copyright © 2001 by W.B. Saunders Company 0010-440X/01/4204-0006$35.00/0 doi:10.1053/comp.2001.24587 306 Comprehensive Psychiatry, Vol. 42, No. 4 (July/August), 2001: pp 306-313