COCAINE'S DAMAGE LINGERS IN BRAIN, STUDY SAYS

Heavy use of cocaine impairs memory, manual dexterity and decision-making
for at least a month after the drug was last taken, according to a new
study of drug users by researchers at the National Institute on Drug Abuse
(NIDA).

The study, led by neurologist Karen Bolla of Johns Hopkins University, adds
to the evidence that the powerful high experienced by cocaine users is
accompanied by long-lasting harm to brain functioning.

The researchers said their work suggests that the brain damage caused by
cocaine might set up a devastating spiral by making it harder for the drug
user to quit. That is because the damage caused by cocaine occurs in the
brain's prefrontal cortex, which is responsible for monitoring behavior and
inhibiting bad behavior.

Traditionally, drug addiction was attributed to moral flaws or "weak
character," she said. "Now we know this drug actually changes the brain. It
may well make it more difficult to stop."

The new paper, published in the Journal of Neuropsychiatry and Clinical
Neuroscience, is written by Bolla, Dr. Jean Lud Cadet and Dr. Richard
Rothman, both of NIDA. They recruited their 30 subjects, mostly smokers of
crack, between 1993 and 1995 in Baltimore.

Cadet said one of the biggest challenges was finding chronic cocaine users
who did not have a history of abusing other drugs - and who were willing to
give up cocaine for a month. The cocaine users had to reside in a NIDA unit
in Baltimore for the 30 days before testing to make certain they were
drug-free.

Their performance on a battery of tests was compared to that of a control
group of 21 people who had no history of drug use but matched the cocaine
users in age, education and IQ score.

Dr. Alan Leshner, director of NIDA, said the study documents behavioral
changes that appear to correspond to changes found in brain scans of
cocaine users.

"It's brain biology and behavior coming together," Leshner said. "It's a
dramatic demonstration that there are residual effects of cocaine that hurt
the skills people need to succeed in school and at work."

While the first research demonstrating a long-term impact of cocaine on
memory and other mental functions was published in 1993, the current study
is the first to find a direct relationship between the amount of cocaine
used and the degree of impairment.

The NIDA study found that people who reported heavy cocaine use -
consumption of two grams or more per week - consistently performed worse on
the neurological tests than those who reported lighter use.

Dr. Tony Strickland, a neuropsychologist at Charles Drew Medical School in
Los Angeles and author of the first study showing lasting brain changes
from cocaine use, said the new paper is "enormously important" in linking
quantity of cocaine used to damage done.

But he cautioned that the work would have to replicated by other
scientists. So far, he said, he has not been able to demonstrate a
dose-related impact in his own research.

Strickland said drugs damage the brain in ways that are not always so
different from that caused by physical blows.

"The brain doesn't necessarily distinguish between whether you were hit in
the head by a ball-peen hammer or whether you suffered this chemical
insult," he said.