COCAINE USE CAN CRIPPLE BRAIN, STUDY FINDS

Research says heavy doses affect dexterity, memory,
decision-making

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.

The study, led by neurologist Karen Bolla of the 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 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 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, 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 the National Institute on Drug Abuse. They
recruited their 30 subjects, mostly smokers of crack, between 1993 and
1995 at the federal institute's clinical research unit.

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.

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, institute director, 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 study found that people who reported heavy cocaine use -
consumption of 2 grams or more a week - consistently performed worse
on the neurological tests than those who reported lighter use.

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.

Michael Gimbel, director of substance abuse for Baltimore County, Md.,
said the research coincides with the subjective impressions of those
who counsel cocaine abusers.

"It's always reassuring to find technical evidence to confirm what
those of us in the field experience with cocaine addicts every day,"
said Gimbel, who oversees the county's treatment programs. "It will
help us in educating the addicts about the effects of the drug."

Gimbel said he found intriguing the idea that cocaine might injure the
part of the brain responsible for impulse control.

"Every coke addict that gets clean says, 'Why in the world did I do
that to myself?' This helps answer that question," he said.