NEW ORLEANS -- A first-of-its-kind study may provide clues to a person's predisposition to abuse drugs, according to findings released at the 2001 annual meeting of the American Society of Anesthesiologists.  At the meeting, researchers from the University of Iowa and Yale University presented new information about the hazards of illicit drugs and alcohol abuse.

In a significant departure from other drug research, the University of Iowa researchers looked at chronic abusers' cognitive skills during childhood as well as their current level of functioning. The data came from participants' fourth-grade scores on the Iowa Tests of Basic Skills, standard measures of academic ability given to students in Iowa and elsewhere. This information provided a comparison of participants' academic achievement with their cognitive skills as adults in drug rehabilitation.

Most drug abuse studies have either ignored participants' earlier cognitive abilities or tried to estimate them, anesthesiologist Mohamed M. Ghoneim, M.D., noted. The drug abusers scored significantly lower than the control group of nonusers. However, as adults, they performed even worse than would be expected, given the original gap between the drug abusers and the control group as children.

"We found impairments in drug users versus the controls that can't be explained solely by their deficits as children," Dr. Ghoneim said. "This discovery points to an additional impairment from drug abuse."

The fact that drug users scored lower on a wide range of cognitive tests does not mean that all drug users are less intelligent than the general population, Dr. Ghoneim stressed. In fact, people of all intellectual abilities abuse drugs. However, this study looked at drug abusers in rehab. "Drug abusers with lower cognitive skills may tend to wind up in treatment more. Those in treatment may tend to get into more trouble with their employers, families and others," he said.

The study points to the importance of cognitive ability before development of an addiction as a predictor of drug abuse. "Future research should take this factor into account," he said. The researchers plan to look next at the influence of intellectual ability on an individual's success in drug rehabilitation, he said.

At the ASA meeting, the University of Iowa researchers reported the results of a study comparing 180 patients in drug rehabilitation to a control group of 137 non-drug users.  The study revealed that drug and alcohol abuse affects memory, reading comprehension and abstract thought and that some of these cognitive impairments persist long after the abuse has stopped.

Chronic drug use has long-lasting effects on brain function that either take a long time to improve or may never improve, according to the study led by psychologist Robert I. Block, Ph.D.

The researchers tested chronic abusers of alcohol, stimulants (cocaine or amphetamines) marijuana or polydrug users (users with problems with two or more drugs) at about two to three weeks and again at 11 to 15 weeks after their last drug use. They tested the control group at the same intervals. The two groups did not differ statistically in age, race, parental socioeconomic status, education and incidence of mood disorders such as anxiety and depression.

Drug abusers performed significantly worse than the controls on standard tests of reading comprehension, verbal expression, mathematics, memory, concept formation and vocabulary. The stimulant users performed the worst of the three drug groups.  All three groups of drug users showed improvement in only one area, memory, after three months of abstinence. These results may have some real-world validity that carries over into treatment for chemical dependence, Dr. Ghoneim said.

"If patients who have recently stopped using drugs continue to have cognitive dysfunction, that impairment could affect their ability to retain information," he said. And because drug rehab often involves a lot of education, health care professionals may be able to enhance treatment by presenting information more slowly, repeating it more and checking more for retention, Dr. Ghoneim said.

In a separate study conducted by Yale University anesthesiologist Zeev N. Kain, M.D., the popular designer drugs Ecstasy and Eve have reportedly presented deadly reactions in some abusers, even those using the drug for the first time.   Dr. Kain said anesthesiologists are finding themselves on the frontline in the treatment of adolescents who overdose due to the deadly temperature aberrations associated with these newer recreational drugs.

The amphetamines, often consumed in perilous quantities by youngsters at large dance parties called "raves," produce euphoria, alertness and lack of inhibition. They can also set off an avalanche of life-threatening complications, including the rapid escalation of body temperature called hyperthermia, muscle rigidity, muscle cell damage, kidney, liver and heart failure and cerebral hemorrhage (bleeding in the brain).

Anesthesiologists' expertise in the management of body temperature during surgery, including the treatment of malignant hyperthermia (a very rare but potentially fatal disorder triggered by some anesthetic agents) make them uniquely qualified to treat the serious temperature swings characteristic of designer-drug overdoses, Dr. Kain said.

"I predict we're going to see more overdoses as these drugs become more popular," he added. "Anesthesiologists must be prepared to handle these cases."

---American Society of Anesthesiologists

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