UPTON, NY -- Recent cocaine use may hide some of the cognitive deficits commonly experienced by individuals addicted to cocaine, scientists at the U.S. Department of Energy’s Brookhaven National Laboratory report in a study published in the April 2009 issue of Neuropsychopharmacology — a special issue dedicated to cocaine research. The study was part of an effort to better understand individual differences among cocaine-addicted subjects to help clinicians develop more effective treatment plans.
Scientists first administered drug-screening urine drug tests to identify subjects who had used cocaine within the last 72 hours The main finding: “The deficits were most obvious in the cocaine-addicted individuals who had been abstinent from cocaine longer than 72 hours,” Woicik said, “and this effect was not due to withdrawal-related depressive symptoms.” Surprisingly, the subjects with the most cognitive impairment reported the least depression and vice versa.
Following the screening test, all participants completed a battery of drug tests that measured attention and executive function (e.g., planning ability), memory and learning, and motor function.
The main finding: “The deficits were most obvious in the cocaine-addicted individuals who had been abstinent from cocaine longer than 72 hours,” Woicik said, “and this effect was not due to withdrawal-related depressive symptoms.” Surprisingly, the subjects with the most cognitive impairment reported the least depression and vice versa.
The scientists also tested other factors that frequently differ between cocaine-addicted individuals and healthy populations — such as cigarette smoking and frequency of alcohol consumption — none of which changed the results.
The finding of less impairment in recent users of cocaine led Woicik to speculate that this better cognitive functioning as associated with recent cocaine use may potentially predispose cocaine-addicted individuals to relapse. “This notion is consistent with a self-medicating hypothesis of addiction, which suggests that addiction results from continual use of a specific drug for its remedial effects,” she said. “In other words, an individual can become addicted to a specific drug because its unique psychopharmacologic action reduces emotional (e.g., negative mood) or cognitive (e.g., poor attention) deficits with which the individual struggles.”
This study was supported by grants from the NIDA; a NARSAD Young Investigator Award; a Stony Brook University/Brookhaven National Laboratory seed grant; the National Institute on Alcohol Abuse and Alcoholism; Brookhaven’s own Laboratory Directed Research and Development fund; and the General Clinical Research Center of Stony Brook University.