Abstract
BACKGROUND: Little data exist on the neuropsychological effects of crack-cocaine dependence or crack-cocaine and alcohol dependence. This study examined cognitive function in abstinent crack dependent and crack and alcohol dependent individuals at 6 weeks and 6 months abstinence. METHODS: a comprehensive neuropsychological battery, including the MicroCog computerized assessment, was administered to 20 abstinent crack dependent subjects, 37 abstinent crack and alcohol dependent subjects, and 29 normal controls. Depression was examined as a covariate, and the association between substance use variables and neuropsychological performance was examined. RESULTS: the two substance dependent groups had similar neuropsychological profiles at 6 weeks abstinent, with both groups exhibiting significant cognitive impairment in a wide range of functions compared to controls. The substance dependent groups were still impaired significantly at 6 months of abstinence. Only mild effects of depression on neuropsychological performance were observed. CONCLUSIONS: crack dependence and crack and alcohol dependence may lead to severe and persistent neuropsychological deficits over a wide range of domains. The strongest predictor of brain damage associated with substance dependence in this sample was dose (particularly quantity and duration of peak dose).