Neuropsychological impairment in chronic cocaine abusers.

Twenty chronic cocaine abusers were compared with age and education matched controls using standardized neuropsychological assessment procedures to determine whether the cocaine abusers were impaired. Fifty percent of the cocaine abusers in contrast to 15% of the controls scored in the impaired range on the summary index of the Neuropsychological Screening Exam. The cocaine abusers also performed more poorly on the Halstead Category Test, the Symbol Digit Modalities Test, the WAIS-R Arithmetic Test, and a test of verbal memory (forgetting). In the cocaine abuser sample, neuropsychological performance was related to the amount and recency of cocaine use, suggesting a direct role of cocaine on cognitive functioning.