MEMORY THAT REVIVES ADDICTION

NEW YORK---As anyone who has tried to quit smoking knows, it is much easier
to get off an addictive drug than to stay off it. That applies to virtually
all addicts and all types of addictions, whether to alcohol, cocaine,
heroin, nicotine or amphetamines.

Long after the drug is cleared from the body, it retains a powerful hold on
the mind, and despite weeks, months or sometimes even years of abstinence,
cravings can linger or suddenly make a shattering comeback. The usual,
devastating consequence is relapse.

"Prolonged drug use changes the brain in fundamental and lasting ways,"
said Alan Leshner, director of the National Institute on Drug Abuse. Those
long-term effects are not well understood, Mr. Leshner said, and learning
more about them might lead to new treatments at offer lasting help to addicts.

Help is certainly needed: The institute estimates that 4 million Americans
are drug addicts, including 2 to 3 million hooked on cocaine and 800,000 on
heroin. Millions more, though not addicted, use illegal drugs, and 14
million are alcoholics.

Compared with people who have other mental or physical disorders, addicts
have few treatments to choose from. No drug treatment is available for
cocaine addiction. Methadone helps some heroin addicts, but by no means
all, and two other drugs are useful in only a minority of alcoholics.

In recent years, much addiction research has focused on the reinforcing,
orpleasureproducing properties of drugs, which have been traced to their
ability to flood certain parts of the brain with dopamine, a substance that
nerve cells use to communicate with each other. But even though the rise
and fall of dopamine can alter brain cells in ways that contribute to
craving, researchers do not think those alterations explain all the
long-term mental effects of drug abuse.

As a result, the emphasis in addiction research has begun to shift, to move
beyond the dopamine pleasure centers to other systems in the brain. "We've
learned a lot about reinforcement," said Eric Nestler, an addiction
researcher at Yale University. "But there are other aspects to an addict's
life also, having to do with memory and conditioning. Maybe the time is
ripe to examine those."

Some changes in the brains of addicts resemble changes that take place in
healthy people when certain types of memories are formed. In some cases,
Dr. Nestler's research has shown, those changes even include alterations in
the fimctioning of.genes. Alcino S ilva, who studies memory at the
University of California at Lcs Angeles, said, "Addiction may hijack
natural systerms used for learning and memory."

Addiction researchers have be gun to pay particular attention to "emotional
memories," which are the mental re cords of events that aroused intense
emotions. "Emotional memories are very wwerful, and they're the ones that
re rnain with you the longest," said Jonathan Pollock, a program officer at
the institute. "You remember where you were when Kennedy was assasinated or
the Challenger disaster happened. You remember very pleasurable events in
your life, like your wedding or the first time you got an A in school."

The intensity of the moment helps to burn emotional memories into brain
circuits. The memories are encoded into a part of the brain that opera.tes
outside conscious control. When emotional memories are reactivated, touched
off perhaps by a smell, a taste, a snatch of music, the sight of an old
friend or some other signal that a person may not even be consciously aware
of, they can evoke the same powerful emotions that helped form them.

Many addiction researchers believe memories of being high on drugs fall
into this category of emotional memories, and contribute to cravi.ng,
compulsion and relapse. Many addicts say that cravings are brought on by
cues or reminders of past drug use, like seeing a needle or crack pipe or
visiting a place where they used to get high.

Stress can also rekindle cravings. So can just one hit of an addicting
drug, even after a long abstinence.

Last month, Mr. Pollock invited 15 researchers to the National Institutes
of Health to discuss the wssible role of emotional memory in addiction. He
said it was the first time that experts on addiction and experts on memory
had been brought together.

Much of the interest in emotional memory stems from studies by Joseph
LeDoux, a researcher at New York University. Working with rats that have
been trained by means of electrical shocks to fear a certain sound ---a
reswnse that qualifies as an emotional memory---he has found that emotional
memories are formed in the amygdala, an almond-shaped structure deep within
the brain.

THE job of the amygdala Dr. LeDoux said is to react instantly when it
detects a danger signal, sending out messages that prepare the body for
fight or flight and that create a state of fear. The human amygdala works
in much the same way. It reacts in a few thousandths of a second,
independent of the cortex of the brain, which means that- people may reswnd
to cues of which they are not consciously aware.

Although Dr. LeDoux has worked mainly on fear, that is not all the amygdala
mediates. It includes 13 areas, some of which may process other types of
emotional memory.

"The amygdala is showing up in a lot of addiction studies," Dr. LeDoux said.

When addicts who say they are in the throes of a craving are given brain
scans, the images suggest that the amygdala is involved, according to
studies by Hans Breiter of the Massachusetts General Hospital and Annarose
Childress of the University of Pennsylvania in Philadelphia.

Other researchers have also found that the amygdala is imwrtant in
responding to cues associated with rewards like cocaine and food.

Ultimately, Dr. Leshner said, he expected that treatment of addiction would
combine behavioral therapy and drugs that combat craving and compulsion.

MEMORY THAT REVIVES ADDICTION

NEW YORK---As anyone who has tried to quit smoking knows, it is much easier
to get off an addictive drug than to stay off it. That applies to virtually
all addicts and all types of addictions, whether to alcohol, cocaine,
heroin, nicotine or amphetamines.

Long after the drug is cleared from the body, it retains a powerful hold on
the mind, and despite weeks, months or sometimes even years of abstinence,
cravings can linger or suddenly make a shattering comeback. The usual,
devastating consequence is relapse.

"Prolonged drug use changes the brain in fundamental and lasting ways,"
said Alan Leshner, director of the National Institute on Drug Abuse. Those
long-term effects are not well understood, Mr. Leshner said, and learning
more about them might lead to new treatments at offer lasting help to addicts.

Help is certainly needed: The institute estimates that 4 million Americans
are drug addicts, including 2 to 3 million hooked on cocaine and 800,000 on
heroin. Millions more, though not addicted, use illegal drugs, and 14
million are alcoholics.

Compared with people who have other mental or physical disorders, addicts
have few treatments to choose from. No drug treatment is available for
cocaine addiction. Methadone helps some heroin addicts, but by no means
all, and two other drugs are useful in only a minority of alcoholics.

In recent years, much addiction research has focused on the reinforcing,
orpleasureproducing properties of drugs, which have been traced to their
ability to flood certain parts of the brain with dopamine, a substance that
nerve cells use to communicate with each other. But even though the rise
and fall of dopamine can alter brain cells in ways that contribute to
craving, researchers do not think those alterations explain all the
long-term mental effects of drug abuse.

As a result, the emphasis in addiction research has begun to shift, to move
beyond the dopamine pleasure centers to other systems in the brain. "We've
learned a lot about reinforcement," said Eric Nestler, an addiction
researcher at Yale University. "But there are other aspects to an addict's
life also, having to do with memory and conditioning. Maybe the time is
ripe to examine those."

Some changes in the brains of addicts resemble changes that take place in
healthy people when certain types of memories are formed. In some cases,
Dr. Nestler's research has shown, those changes even include alterations in
the fimctioning of.genes. Alcino S ilva, who studies memory at the
University of California at Lcs Angeles, said, "Addiction may hijack
natural systerms used for learning and memory."

Addiction researchers have be gun to pay particular attention to "emotional
memories," which are the mental re cords of events that aroused intense
emotions. "Emotional memories are very wwerful, and they're the ones that
re rnain with you the longest," said Jonathan Pollock, a program officer at
the institute. "You remember where you were when Kennedy was assasinated or
the Challenger disaster happened. You remember very pleasurable events in
your life, like your wedding or the first time you got an A in school."

The intensity of the moment helps to burn emotional memories into brain
circuits. The memories are encoded into a part of the brain that opera.tes
outside conscious control. When emotional memories are reactivated, touched
off perhaps by a smell, a taste, a snatch of music, the sight of an old
friend or some other signal that a person may not even be consciously aware
of, they can evoke the same powerful emotions that helped form them.

Many addiction researchers believe memories of being high on drugs fall
into this category of emotional memories, and contribute to cravi.ng,
compulsion and relapse. Many addicts say that cravings are brought on by
cues or reminders of past drug use, like seeing a needle or crack pipe or
visiting a place where they used to get high.

Stress can also rekindle cravings. So can just one hit of an addicting
drug, even after a long abstinence.

Last month, Mr. Pollock invited 15 researchers to the National Institutes
of Health to discuss the wssible role of emotional memory in addiction. He
said it was the first time that experts on addiction and experts on memory
had been brought together.

Much of the interest in emotional memory stems from studies by Joseph
LeDoux, a researcher at New York University. Working with rats that have
been trained by means of electrical shocks to fear a certain sound ---a
reswnse that qualifies as an emotional memory---he has found that emotional
memories are formed in the amygdala, an almond-shaped structure deep within
the brain.

THE job of the amygdala Dr. LeDoux said is to react instantly when it
detects a danger signal, sending out messages that prepare the body for
fight or flight and that create a state of fear. The human amygdala works
in much the same way. It reacts in a few thousandths of a second,
independent of the cortex of the brain, which means that- people may reswnd
to cues of which they are not consciously aware.

Although Dr. LeDoux has worked mainly on fear, that is not all the amygdala
mediates. It includes 13 areas, some of which may process other types of
emotional memory.

"The amygdala is showing up in a lot of addiction studies," Dr. LeDoux said.

When addicts who say they are in the throes of a craving are given brain
scans, the images suggest that the amygdala is involved, according to
studies by Hans Breiter of the Massachusetts General Hospital and Annarose
Childress of the University of Pennsylvania in Philadelphia.

Other researchers have also found that the amygdala is imwrtant in
responding to cues associated with rewards like cocaine and food.

Ultimately, Dr. Leshner said, he expected that treatment of addiction would
combine behavioral therapy and drugs that combat craving and compulsion.

Checked-by: Pat Dolan