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August 1976

A Neuropsychological Study of Polydrug Users

Author Affiliations

From the Department of Psychiatry, University of California, San Diego, and the Veterans Administration Hospital, San Diego (Drs Grant and Miller and Ms Mohns), and the Child Development and Mental Retardation Center, University of Washington, Seattle (Dr Reitan).

Arch Gen Psychiatry. 1976;33(8):973-978. doi:10.1001/archpsyc.1976.01770080091009

• The long-term neuropsychological effects of persistent nonmedical drug use are still unknown. In this study, 22 young men, all extensive "polydrug" users, were examined while free from drugs for an average of 60 days by means of the Halstead-Reitan Neuropsychological Test Battery. Their performance was compared to that of age-education-sex-matched neurologically intact medical patients and a similarly matched group of neurologically impaired patients.

Blind independent ratings of test protocols by two experienced clinicians judged 41% to 64% of the drug users, 11% to 26% of the medical patients, and 84% to 89% of the neurologic patients to be impaired. Interpretation of these results suggests that in some individuals, heavy "polydrug" use may be associated with neuropsychological dysfunction, which persists at least an average of two months beyond cessation of drug use.

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