Cocaine users have trouble with self-control and decision making, even after they’ve given up the drug, according to a study by researchers at the School of Medicine. “It’s thought that this impairment in inhibitory control may contribute to certain aspects of drug abuse, such as craving, bingeing and risky behaviors,” said Jane R. Taylor, Ph.D., associate professor in the division of molecular psychiatry and senior author of the study, published in the February issue of Neuropsychopharmacology.
In a study of primates funded by the National Institute on Drug Abuse, Taylor and colleagues investigated whether an impairment in the orbitofrontal cortex leads to drug abuse, or whether it develops as a consequence of drug abuse.
The primates were trained to recognize that food was available under only one of three objects. Then the food was placed under a different object. The primates had to inhibit their learned response and choose the other object. Unlike the control animals, primates injected with cocaine were not able to inhibit their initial response and continued to reach for the original object. “While these deficits could be interpreted as indicating that addicts have an underlying orbitofrontal dysfunction that predisposes them to drug abuse, our results indicate that prior cocaine exposure is sufficient to produce cognitive defects reminiscent of orbitofrontal cortical dysfunction,” the researchers wrote. “The frontal-lobe impairments in drug abusers may be a consequence of, as well as a predisposing factor to, addiction.”