The NIDA-supported researchers administered a battery of comprehensive neuropsychological tests to 20 crack-dependent subjects, 37 crack-and-alcohol-dependent subjects, and 29 individuals with no history of drug or alcohol abuse. The tests were given twice-the first time following 6 weeks of abstinence from drugs and again after 6 months of drug abstinence. The tests assessed the subjects' attention span, decision-making, spatial processing, immediate and delayed memory, calculation ability, reaction time, verbal fluency, and psychomotor skills.
Both drug-abusing groups showed significant cognitive impairments at both the 6-week and the 6-month time points. The largest effects were found in the executive function and spatial processing assessments.
WHAT IT MEANS: With approximately 2 million cocaine abusers in the United States, the finding that brain damage resulting in long-term impaired mental and physical functioning can result from its use makes developing and utilizing effective prevention and treatment methods an urgent public health priority.
The study was published in the February 2002 issue of Drug and Alcohol Dependence by a research team from Neurobehavioral Research, Inc., Corte Madera, CA; University of Illinois at Chicago; and the Herrick/Alta Bates Hospital, Berkeley, CA. Dr. George Fein was the lead author.