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Re: News: Lasting Pleasures, Robbed by Drug Abuse

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  • Donald W.
    ... DWZ: That makes a lot of sense, and I would be surprised if it doesn t turn out to be on the right track. Those findings may have educational implications.
    Message 1 of 8 , Sep 1, 2010
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      --- In evolutionary-psychology@yahoogroups.com, "Robert Karl Stonjek" <stonjek@...> wrote:
      >
      > August 30, 2010
      > Lasting Pleasures, Robbed by Drug Abuse
      > By RICHARD A. FRIEDMAN, M.D.

      > We understand the initial allure of recreational drugs pretty well. Whether it is cocaine, alcohol, opiates, you name it, drugs rapidly activate the brain's reward system — a primitive neural circuit buried beneath the cortex — and release dopamine. This neurotransmitter, which is central to pleasure and desire, sends a message to the brain: This is an important experience that is worth remembering.
      >
      > We would not have gotten very far as a species without this brain system to motivate us to seek out rewards like food and a nice mate. The trouble is that while such natural reinforcers activate the reward system, mind-altering drugs do it much more powerfully, causing a far greater dopamine release.
      >
      > In other words, drugs have a competitive advantage over these natural rewards and can hijack the brain's reward system.
      >
      > Even so, the acute pleasure fades when the neurons in the reward circuit get used to all that dopamine. Eventually, as with my patient, even higher and higher doses cease to feel good as users try in vain to recapture the initial high.


      DWZ:
      That makes a lot of sense, and I would be surprised if it doesn't turn out to be on the right track. Those findings may have educational implications. In the past many of the warnings given to young people about illegal drugs have been related to morality, law enforcement, religious prohibition, unrealistic health concerns, and such.

      Perhaps a more common-sense approach, taking into consideration the scientific findings, would be more effective. Young kids can be told: "Yes, those drugs will make you feel good, but later you will feel a lot worse." Or maybe something like "Would you take a free dollar to add to your allowance today if you have to pay back ten dollars next week?"

      If Jimmy at school tells Billy that the white powder will make him feel good and the parents say "No! No! Stay away from it. It is unlawful. the police will get you!" then Billy, after trying out the powder and the police do not come will say; "I feel good. They lied to me. This stuff is great, and I will keep on using it more." But concern about a future "payback" for temporary gain might work better.

      I like to think of drug addiction as "Nature's Ponzi scheme." Some versions of that classic scam are legal, some illegal. In one version, an investor is persuaded to put up a substantial amount of money in order to get an extraordinary rate of return (15% seems to be a favorite). For a while, big monthly checks keep on coming, and the mark stays happy. The day of reckoning comes when the scheme collapses or the mark wants the original capital back and finds out that it has been greatly depleted or gone entirely. The monthly checks have just been payments from the investors own money (or some other mark's money). Joy turns to grief.

      Substitute "dopamine resources" for "capital" and "dopamine rush" for "monthly income," and the analogy may not be too far fetched.

      Best regards,

      Donald W. Zimmerman
      Vancouver, BC, Canada
      dwzimm@...
      http://mypage.direct.ca/z/zimmerma/index.html
    • Helga V
      I think something very similar happens with nicotine. There is an initial rush that feels very relaxing and pleasant, but this is soon lost, although the
      Message 2 of 8 , Sep 1, 2010
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        I think something very similar happens with nicotine. There is an initial "rush" that feels very relaxing and pleasant, but this is soon lost, although the person continues to smoke. Maybe more "hits" will produce a rush? But even though the person gets all kinds of negative effects - like a bad taste in the mouth making them want to spit all the time when smoking, they still cannot easily quit. It is because of the social associations, and the enjoyment of the "break" when the person is stilled and surrounded by drifting smoke - perhaps it is that calming moment that draws them back to smoke again and again.

        I have good friends who seem to desperately want to quit smoking and yet fall back into it very easily if they meet with friends who still smoke. It is sad to see all the good intentions defeated again and again.

        I also think that the pleasure we get from love, sex, good food, socializing etc is pretty special - and to have this become permanently diminished because of an addiction indicates an extreme vulnerability in the brain of the human species. This ought not be a matter that people assume is just about morality, willpower, and "making choices". I suspect that beyond a certain point, the individual needs tremendous support to rebuild their life; since it is a matter of teaching them to outsmart the pleasure seeking part of their own brain! How do you do that!

        regards, Helga

        --- In evolutionary-psychology@yahoogroups.com, "Donald W." <dwzimm@...> wrote:
        >
        > --- In evolutionary-psychology@yahoogroups.com, "Robert Karl Stonjek" <stonjek@> wrote:
        > >
        > > August 30, 2010
        > > Lasting Pleasures, Robbed by Drug Abuse
        > > By RICHARD A. FRIEDMAN, M.D.
        >
        > > We understand the initial allure of recreational drugs pretty well. Whether it is cocaine, alcohol, opiates, you name it, drugs rapidly activate the brain's reward system — a primitive neural circuit buried beneath the cortex — and release dopamine. This neurotransmitter, which is central to pleasure and desire, sends a message to the brain: This is an important experience that is worth remembering.
        > >
        > > We would not have gotten very far as a species without this brain system to motivate us to seek out rewards like food and a nice mate. The trouble is that while such natural reinforcers activate the reward system, mind-altering drugs do it much more powerfully, causing a far greater dopamine release.
        > >
        > > In other words, drugs have a competitive advantage over these natural rewards and can hijack the brain's reward system.
        > >
        > > Even so, the acute pleasure fades when the neurons in the reward circuit get used to all that dopamine. Eventually, as with my patient, even higher and higher doses cease to feel good as users try in vain to recapture the initial high.
        >
        >
        > DWZ:
        > That makes a lot of sense, and I would be surprised if it doesn't turn out to be on the right track. Those findings may have educational implications. In the past many of the warnings given to young people about illegal drugs have been related to morality, law enforcement, religious prohibition, unrealistic health concerns, and such.
        >
        > Perhaps a more common-sense approach, taking into consideration the scientific findings, would be more effective. Young kids can be told: "Yes, those drugs will make you feel good, but later you will feel a lot worse." Or maybe something like "Would you take a free dollar to add to your allowance today if you have to pay back ten dollars next week?"
        >
        > If Jimmy at school tells Billy that the white powder will make him feel good and the parents say "No! No! Stay away from it. It is unlawful. the police will get you!" then Billy, after trying out the powder and the police do not come will say; "I feel good. They lied to me. This stuff is great, and I will keep on using it more." But concern about a future "payback" for temporary gain might work better.
        >
        > I like to think of drug addiction as "Nature's Ponzi scheme." Some versions of that classic scam are legal, some illegal. In one version, an investor is persuaded to put up a substantial amount of money in order to get an extraordinary rate of return (15% seems to be a favorite). For a while, big monthly checks keep on coming, and the mark stays happy. The day of reckoning comes when the scheme collapses or the mark wants the original capital back and finds out that it has been greatly depleted or gone entirely. The monthly checks have just been payments from the investors own money (or some other mark's money). Joy turns to grief.
        >
        > Substitute "dopamine resources" for "capital" and "dopamine rush" for "monthly income," and the analogy may not be too far fetched.
        >
        > Best regards,
        >
        > Donald W. Zimmerman
        > Vancouver, BC, Canada
        > dwzimm@...
        > http://mypage.direct.ca/z/zimmerma/index.html
        >
      • Donald W.
        ... DWZ: Yes, and I would not be surprised if all addictions to substances of abuse, including the more socially tolerated ones like nicotine and alcohol, work
        Message 3 of 8 , Sep 2, 2010
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          --- In evolutionary-psychology@yahoogroups.com, "Helga V" <helgav@...> wrote:
          >
          > I think something very similar happens with nicotine. There is an initial "rush" that feels very relaxing and pleasant, but this is soon lost, although the person continues to smoke. Maybe more "hits" will produce a rush? But even though the person gets all kinds of negative effects - like a bad taste in the mouth making them want to spit all the time when smoking, they still cannot easily quit. It is because of the social associations, and the enjoyment of the "break" when the person is stilled and surrounded by drifting smoke - perhaps it is that calming moment that draws them back to smoke again and again.
          >
          > I have good friends who seem to desperately want to quit smoking and yet fall back into it very easily if they meet with friends who still smoke. It is sad to see all the good intentions defeated again and again.
          >
          > I also think that the pleasure we get from love, sex, good food, socializing etc is pretty special - and to have this become permanently diminished because of an addiction indicates an extreme vulnerability in the brain of the human species. This ought not be a matter that people assume is just about morality, willpower, and "making choices". I suspect that beyond a certain point, the individual needs tremendous support to rebuild their life; since it is a matter of teaching them to outsmart the pleasure seeking part of their own brain! How do you do that!


          DWZ:
          Yes, and I would not be surprised if all addictions to substances of abuse, including the more socially tolerated ones like nicotine and alcohol, work in much the same way with respect to brain chemistry. It is a question of present pleasure resulting from too much of something gradually giving way to future pain resulting from too little of it. The process turns into a continual chase for repetition of an experience that steadiy diminishes as it is repeated. If that is true, then effective educational programs for the various types of addictions may necessarily be very similar. I am thinking here mainly of prevention or persuading people not to use the substances in the first place. Treatment for existing addiction is a somewhat different problem because of the neurological changes that occur.

          If this hypothesis is true, then a good predictor of the likelihood of addiction developing in the first place is the extent to which a person is capable of delayed gratification in general. A young person who has trouble with discipline and planning for the future may also be prone to using drugs without thought of future consequences.

          A related problem is what might be called the "I am special" syndrome. An individual experimenting with substances often knows some of the facts about addiction, but underestimates the degree of personal risk. That attitude goes hand in hand with our concepts of free-will and an inner agent initiating action. "I can handle it," or "It will never happen to me," etc. You hear this all the time in regard to alcohol especially. People are not quite as "strong willed" and capable of "free choice" as they believe themselves to be, and their assessment of risks and probabilities can be way off the mark.

          Best regards,

          Donald W. Zimmerman
          Vancouver, BC, Canada
          dwzimm@...
          http://mypage.direct.ca/z/zimmerma/index.html
        • ED
          This issue and others concerning addiction, etc. are explained in a Charlie Rose panel discussion, transcript at:
          Message 4 of 8 , Sep 3, 2010
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            This issue and others concerning addiction, etc. are explained in a Charlie Rose panel discussion, transcript at:

            http://www.charlierose.com/view/interview/10974#frame_top

            --ED

             

            --- In evolutionary-psychology@yahoogroups.com, "Robert Karl Stonjek" <stonjek@...> wrote:
            >
            August 30, 2010

            Lasting Pleasures, Robbed by Drug Abuse

            By RICHARD A. FRIEDMAN, M.D.
            Scott Menchin

            Of all the things that people do, few are as puzzling to psychiatrists as compulsive drug use.

            Sure, all drugs of abuse feel good — at least initially. But for most people, the euphoria doesn't last. A patient of mine is all too typical.

            "I know this will sound strange," he said, as I recall, "but cocaine doesn't get me high any more and still I can't stop."

            When he first started using the drug, in his early 30s, my patient would go for days on a binge, hardly eating or drinking. The high was better than anything, even sex.

            Within several months, though, he had lost the euphoria — followed by his job. Only when his wife threatened to leave him did he finally seek treatment.

            When I met him, he told me that he would lose everything if he could not stop using cocaine. Well, I asked, what did he like about this drug, if it cost him so much and no longer made him feel good? He stared at me blankly. He had no clue.

            Neither did most psychiatrists, until recently.

            We understand the initial allure of recreational drugs pretty well. Whether it is cocaine, alcohol, opiates, you name it, drugs rapidly activate the brain's reward system — a primitive neural circuit buried beneath the cortex — and release dopamine. This neurotransmitter, which is central to pleasure and desire, sends a message to the brain: This is an important experience that is worth remembering.

            We would not have gotten very far as a species without this brain system to motivate us to seek out rewards like food and a nice mate. The trouble is that while such natural reinforcers activate the reward system, mind-altering drugs do it much more powerfully, causing a far greater dopamine release.

            In other words, drugs have a competitive advantage over these natural rewards and can hijack the brain's reward system.

            Even so, the acute pleasure fades when the neurons in the reward circuit get used to all that dopamine. Eventually, as with my patient, even higher and higher doses cease to feel good as users try in vain to recapture the initial high.

            So what explains compulsive drug use, especially when it brings the user to the brink of personal ruin?

            I got a clue from my patient's recent relapse. After nearly six months of abstinence, he found himself inexplicably craving cocaine on the way home from work.

            It happened that he had run into an old friend just outside his office with whom he had used drugs years earlier. Although he did not consciously associate the friend and the drugs, his brain had not forgotten, and the meeting touched off the urge to use again.

            In short, recreational drugs like cocaine don't just usurp the brain's reward circuit; they have powerful effects on learning and memory.

            Many brain imaging studies, using positron emission tomography, show that cues like viewing drug paraphernalia are enough by themselves to activate memory circuits and unleash drug craving. Where you are and what you are doing when you use a drug like cocaine is inextricably linked with the high. And these associations are stored not just in your conscious memory, but also in memory circuits outside your awareness.

            This kind of pathologic learning lies at the heart of compulsive drug use. Long after someone has apparently kicked the habit, long after withdrawal symptoms subside, the individual is vulnerable to these deeply encoded unconscious associations that can set off a craving, seemingly out of the blue.

            I could not rewire my patient's brain. But at least I could try to help him reconfigure his environment by avoiding cues that might provoke cocaine craving. I had him make an inventory of all the people and places he associated with his drug use — and then had him steer clear of as many as he could. Lucky for him that he never used drugs at home.

            His problems did not end there, however. Although he has been cocaine-free for nearly two years, he feels life is lackluster and little excites him. And that experience is consistent with recent evidence that the effects of drugs like cocaine can endure long after use has ended.

            Dr. Nora D. Volkow, a psychiatrist who is director of the National Institute on Drug Abuse, has shown using PET scans that methamphetamine-dependent subjects have about 25 percent fewer dopamine transporters in critical brain regions compared with normal volunteers. Since the transporters ferry dopamine in and out of neurons, this decrease means less dopamine release and a less responsive reward circuit.

            Alarmingly, this reduction in dopamine transporters was present in subjects who had not used methamphetamine for at least 11 months, suggesting that the effect was long-lasting — perhaps even permanent.

            Though my patient had not used methamphetamine, cocaine has similar effects in the brain. With years of abuse, he could have lost enough dopamine transporters that his own reward circuit would become dulled to everyday pleasures. After all, to most brains a fine dinner with friends or a beautiful sunset is no match for the euphoria of cocaine.

            We do not yet know whether the loss of dopamine transporters is permanent or eventually reversible. But why take the chance and endure a dulled life? The plain truth is that drug-induced pleasure is a cruel illusion: it never lasts.

            Dr. Richard A. Friedman is a professor of psychiatry at Weill Cornell Medical College.

            Source: The New York Times
            http://www.nytimes.com/2010/08/31/health/views/31mind.html?_r=1

            Posted by
            Robert Karl Stonjek



          • ED
            NORA VOLKOW: And actually Eric s wife has been instrumental in her work with looking at the epidemiological studies to actually slow that kids that were
            Message 5 of 8 , Sep 3, 2010
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              "NORA VOLKOW:  And actually Eric's wife has been instrumental in her
              work with looking at the epidemiological studies to actually slow that kids
              that were engaging in illicit substances have started by taking nicotine. 

              So the question was is it because that was the first drug that was
              available or is it because those kids that are going to take illicit
              substances will take nicotine, or is nicotine doing something in your
              brain, which is really interesting, that could then make you more
              vulnerable as you grow into an adult to other substances and to addiction. 

              And there is evidence from studies in laboratory animals that, indeed,
              early exposure to nicotine modifies a function of the dopamine cells,
              making them less sensitive to reinforces, to rewards.  And so, yes,
              nicotine exposure early on can have longer lasting effects, certainly in
              laboratory animals, that will affect the way that you're going to be
              responding to drugs. "

              Source: Transcript of Charlie Rose panel discussion at:

              http://www.charlierose.com/view/interview/10974#frame_top

              --ED

               

              --- In evolutionary-psychology@yahoogroups.com, "Helga V" <helgav@...> wrote:
              >
              I think something very similar happens with nicotine. There is an initial "rush"
              that feels very relaxing and pleasant, but this is soon lost, although the
              person continues to smoke. Maybe more "hits" will produce a rush? But even
              though the person gets all kinds of negative effects - like a bad taste in the
              mouth making them want to spit all the time when smoking, they still cannot
              easily quit. It is because of the social associations, and the enjoyment of the
              "break" when the person is stilled and surrounded by drifting smoke - perhaps it
              is that calming moment that draws them back to smoke again and again.

              I have good friends who seem to desperately want to quit smoking and yet fall
              back into it very easily if they meet with friends who still smoke. It is sad to
              see all the good intentions defeated again and again.

              I also think that the pleasure we get from love, sex, good food, socializing etc
              is pretty special - and to have this become permanently diminished because of an
              addiction indicates an extreme vulnerability in the brain of the human species.
              This ought not be a matter that people assume is just about morality, willpower,
              and "making choices". I suspect that beyond a certain point, the individual
              needs tremendous support to rebuild their life; since it is a matter of teaching
              them to outsmart the pleasure seeking part of their own brain! How do you do
              that!

              regards, Helga

              --- In evolutionary-psychology@yahoogroups.com, "Donald W." <dwzimm@...> wrote:
              >
              > --- In evolutionary-psychology@yahoogroups.com, "Robert Karl Stonjek"
              <stonjek@> wrote:
              > >
              > > August 30, 2010
              > > Lasting Pleasures, Robbed by Drug Abuse
              > > By RICHARD A. FRIEDMAN, M.D.
              >
              > > We understand the initial allure of recreational drugs pretty well. Whether
              it is cocaine, alcohol, opiates, you name it, drugs rapidly activate the brain's
              reward system — a primitive neural circuit buried beneath the cortex — and
              release dopamine. This neurotransmitter, which is central to pleasure and
              desire, sends a message to the brain: This is an important experience that is
              worth remembering.
              > >
              > > We would not have gotten very far as a species without this brain system to
              motivate us to seek out rewards like food and a nice mate. The trouble is that
              while such natural reinforcers activate the reward system, mind-altering drugs
              do it much more powerfully, causing a far greater dopamine release.
              > >
              > > In other words, drugs have a competitive advantage over these natural
              rewards and can hijack the brain's reward system.
              > >
              > > Even so, the acute pleasure fades when the neurons in the reward circuit get
              used to all that dopamine. Eventually, as with my patient, even higher and
              higher doses cease to feel good as users try in vain to recapture the initial
              high.
              >
              >
              > DWZ:
              > That makes a lot of sense, and I would be surprised if it doesn't turn out to
              be on the right track. Those findings may have educational implications. In the
              past many of the warnings given to young people about illegal drugs have been
              related to morality, law enforcement, religious prohibition, unrealistic health
              concerns, and such.
              >
              > Perhaps a more common-sense approach, taking into consideration the scientific
              findings, would be more effective. Young kids can be told: "Yes, those drugs
              will make you feel good, but later you will feel a lot worse." Or maybe
              something like "Would you take a free dollar to add to your allowance today if
              you have to pay back ten dollars next week?"
              >
              > If Jimmy at school tells Billy that the white powder will make him feel good
              and the parents say "No! No! Stay away from it. It is unlawful. the police will
              get you!" then Billy, after trying out the powder and the police do not come
              will say; "I feel good. They lied to me. This stuff is great, and I will keep on
              using it more." But concern about a future "payback" for temporary gain might
              work better.
              >
              > I like to think of drug addiction as "Nature's Ponzi scheme." Some versions of
              that classic scam are legal, some illegal. In one version, an investor is
              persuaded to put up a substantial amount of money in order to get an
              extraordinary rate of return (15% seems to be a favorite). For a while, big
              monthly checks keep on coming, and the mark stays happy. The day of reckoning
              comes when the scheme collapses or the mark wants the original capital back and
              finds out that it has been greatly depleted or gone entirely. The monthly checks
              have just been payments from the investors own money (or some other mark's
              money). Joy turns to grief.
              >
              > Substitute "dopamine resources" for "capital" and "dopamine rush" for "monthly
              income," and the analogy may not be too far fetched.
              >
              > Best regards,
              >
              > Donald W. Zimmerman
              > Vancouver, BC, Canada
              > dwzimm@...
              > http://mypage.direct.ca/z/zimmerma/index.html
              >

            • ED
              ... permanent or eventually reversible. But why take the chance and endure a dulled life? The plain truth is that drug-induced pleasure is a cruel illusion: it
              Message 6 of 8 , Sep 3, 2010
              • 0 Attachment


                 

                >  We do not yet know whether the loss of dopamine transporters is permanent or eventually reversible. But why take the chance and endure a dulled life? The plain truth is that drug-induced pleasure is a cruel illusion: it never lasts.

                Dopamine and sex:


                 CHARLIE ROSE:  It's on everybody's mind because of all the stuff
                that's gone on in the last four or five months ago Tiger Woods, the idea of
                sex addiction.  What do we know about that? 

                ERIC KANDEL:  The Coolidge Effect, that a male exposed to female will
                after a while tire of copulating with that female.  But if you show him
                another female, that same male who appears exhausted will all of sudden be
                capable of sexual activity. 

                CHARLIE ROSE:  Why is that?  What happens in the brain to make that
                true? 

                ERIC KANDEL:  There is some habituation going on, familiarity, which
                is no longer reinforcing.  It's very much like addiction. 

                ERIC NESTLER:  Right, expected reward lose value over time. 

                NORA VOLKOW:  But it made me also smile, because it's the same thing
                with food.  With food you can actually -- they put you a piece of meat you
                can tire of it.  But then they bring dessert, even though you're full,
                you'll eat that dessert.  Anything that is novel will be salient and will
                activate the dopamine system.  So that's why it's not surprising --

                CHARLIE ROSE:  Say that again.  Everything gets tired at some point
                and activates --

                NORA VOLKOW:  Becomes tolerant.  So a stimulant that's pleasurable, a
                natural stimulant, will activate the dopamine cells.  But as you become
                satiated, as you repeat it --

                ERIC KANDEL:  It becomes less effective. 

                NORA VOLKOW:  Not with drugs.  And actually that's one of the --

                CHARLIE ROSE:  But why are drugs different? 

                NORA VOLKOW:  You do not become satiated. 

                CHARLIE ROSE:  Is it possible that part of the addiction is to risk? 

                DANIEL SALZMAN:  That's exactly right.  And I think that's one thing
                that characterizes the behavior of people that take enormous risk in
                having, say, multiple sexual partners, right?  So it's not just the sexual
                satisfaction, it's the risk and enjoyment that they get from doing in the
                dangerous situations, right?

                And Wolfram has already spoken a little bit about how risk can
                actually activate dopamine neurons.  And so this danger may accentuate the
                sense of pleasure that they get from these types of activities. 

                WOLFRAM SCHULTZ:  And the interesting thing is some of these same
                reward neurons, like the dopamine neurons, are also activated by risk.  And
                the other brain structure that we know that responds to risk very well, to
                stimuli to predict the risk, is the orbital frontal cortex.  These are not
                the same neurons for reward, but it's the same area.  So they're very close
                by. 

                Source:   Transcript at:   http://www.charlierose.com/view/interview/10974#frame_top

                 

                --- In evolutionary-psychology@yahoogroups.com, "Robert Karl Stonjek" <stonjek@...> wrote:
                >
                August 30, 2010

                Lasting Pleasures, Robbed by Drug Abuse

                By RICHARD A. FRIEDMAN, M.D.
                Scott Menchin

                Of all the things that people do, few are as puzzling to psychiatrists as compulsive drug use.

                Sure, all drugs of abuse feel good — at least initially. But for most people, the euphoria doesn't last. A patient of mine is all too typical.

                "I know this will sound strange," he said, as I recall, "but cocaine doesn't get me high any more and still I can't stop."

                When he first started using the drug, in his early 30s, my patient would go for days on a binge, hardly eating or drinking. The high was better than anything, even sex.

                Within several months, though, he had lost the euphoria — followed by his job. Only when his wife threatened to leave him did he finally seek treatment.

                When I met him, he told me that he would lose everything if he could not stop using cocaine. Well, I asked, what did he like about this drug, if it cost him so much and no longer made him feel good? He stared at me blankly. He had no clue.

                Neither did most psychiatrists, until recently.

                We understand the initial allure of recreational drugs pretty well. Whether it is cocaine, alcohol, opiates, you name it, drugs rapidly activate the brain's reward system — a primitive neural circuit buried beneath the cortex — and release dopamine. This neurotransmitter, which is central to pleasure and desire, sends a message to the brain: This is an important experience that is worth remembering.

                We would not have gotten very far as a species without this brain system to motivate us to seek out rewards like food and a nice mate. The trouble is that while such natural reinforcers activate the reward system, mind-altering drugs do it much more powerfully, causing a far greater dopamine release.

                In other words, drugs have a competitive advantage over these natural rewards and can hijack the brain's reward system.

                Even so, the acute pleasure fades when the neurons in the reward circuit get used to all that dopamine. Eventually, as with my patient, even higher and higher doses cease to feel good as users try in vain to recapture the initial high.

                So what explains compulsive drug use, especially when it brings the user to the brink of personal ruin?

                I got a clue from my patient's recent relapse. After nearly six months of abstinence, he found himself inexplicably craving cocaine on the way home from work.

                It happened that he had run into an old friend just outside his office with whom he had used drugs years earlier. Although he did not consciously associate the friend and the drugs, his brain had not forgotten, and the meeting touched off the urge to use again.

                In short, recreational drugs like cocaine don't just usurp the brain's reward circuit; they have powerful effects on learning and memory.

                Many brain imaging studies, using positron emission tomography, show that cues like viewing drug paraphernalia are enough by themselves to activate memory circuits and unleash drug craving. Where you are and what you are doing when you use a drug like cocaine is inextricably linked with the high. And these associations are stored not just in your conscious memory, but also in memory circuits outside your awareness.

                This kind of pathologic learning lies at the heart of compulsive drug use. Long after someone has apparently kicked the habit, long after withdrawal symptoms subside, the individual is vulnerable to these deeply encoded unconscious associations that can set off a craving, seemingly out of the blue.

                I could not rewire my patient's brain. But at least I could try to help him reconfigure his environment by avoiding cues that might provoke cocaine craving. I had him make an inventory of all the people and places he associated with his drug use — and then had him steer clear of as many as he could. Lucky for him that he never used drugs at home.

                His problems did not end there, however. Although he has been cocaine-free for nearly two years, he feels life is lackluster and little excites him. And that experience is consistent with recent evidence that the effects of drugs like cocaine can endure long after use has ended.

                Dr. Nora D. Volkow, a psychiatrist who is director of the National Institute on Drug Abuse, has shown using PET scans that methamphetamine-dependent subjects have about 25 percent fewer dopamine transporters in critical brain regions compared with normal volunteers. Since the transporters ferry dopamine in and out of neurons, this decrease means less dopamine release and a less responsive reward circuit.

                Alarmingly, this reduction in dopamine transporters was present in subjects who had not used methamphetamine for at least 11 months, suggesting that the effect was long-lasting — perhaps even permanent.

                Though my patient had not used methamphetamine, cocaine has similar effects in the brain. With years of abuse, he could have lost enough dopamine transporters that his own reward circuit would become dulled to everyday pleasures. After all, to most brains a fine dinner with friends or a beautiful sunset is no match for the euphoria of cocaine.

                We do not yet know whether the loss of dopamine transporters is permanent or eventually reversible. But why take the chance and endure a dulled life? The plain truth is that drug-induced pleasure is a cruel illusion: it never lasts.

                Dr. Richard A. Friedman is a professor of psychiatry at Weill Cornell Medical College.

                Source: The New York Times
                http://www.nytimes.com/2010/08/31/health/views/31mind.html?_r=1

                Posted by
                Robert Karl Stonjek

                 

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