The detrimental effects of heavy cocaine use on an individual's manual dexterity, problem solving, and other critical skills can last for up to a month after the drug was taken, according to a study reported in the Summer issue of The Journal of Neuropsychiatry and Clinical Neurosciences. The study, which was conducted by researchers at the Intramural Research Program of the National Institute on Drug Abuse(NIDA) and Johns Hopkins University School of Medicine, found that heavy cocaine users were outperformed by moderate users and non-users on most tests measuring verbal memory, manual dexterity, and other cognitive skills. Heavy cocaine use was defined as two or more grams a week.
NIDA Director Dr. Alan I. Leshner says, "This study adds to the accumulating - and worrisome - evidence that heavy use of cocaine can result in persistent deficits in the skills needed to succeed in school and on the job. Cocaine users are risking their futures. For them, prevention and effective treatment become critical public health priorities."
"These findings underscore the connection between cocaine use and neurobehavioral effects," says Dr. Karen I. Bolla, Associate Professor of Neurology at Johns Hopkins. "While the intensity (grams per week) of cocaine use was more closely associated with decreased performance than the duration of use, all cocaine users in the study experienced reduced cognitive function."
This is the second recent study in which Dr. Bolla has identified persistent cognitive problems in former heavy drug users. In the December 1998 issue of Neurology, she published results showing memory impairment associated with the heavy use of the drug Ecstasy, also known as MDMA. In that study, too, the problem was related to the amount of the drug taken and lasted at least two weeks after stopping use.
Dr. Bolla and Jean Lud Cadet, M.D., Clinical Director and Chief of
Neuropsychiatry at the NIDA Intramural Research Program, studied 30 i
Contact: Beverly Jackson and Michelle Muth
NIH/National Institute on Drug Abuse