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Thursday, June 24, 2004

Opioids, Attachment, and Compulsion
The Compulsion to Repeat the Trauma

From Netscape News, echoing a report in the journal, Science,  comes this report about the neurobiology of attachment.  To place this in context, it is important to be aware of the fact  that there is a long history of research into the role that the internal opioid system plays in social attachment.  In fact, this recent article is only a small contribution.  It is not clear why it was picked up by the Associated Press.  The opioid system in the brain has been suggested to play a role in addiction, eating disorders, and compulsive repetition of trauma.

In this post, I review the recent news article, then discuss the broader scientific context to show why it is important.  I then review some of the clinical applications of the basic science, including the role that the endogenous opiate system (and some other systems) may play is such conditions as addiction, eating disorders, and compulsive repetition of trauma.
Here is an excerpt of the article that inspired me to write this post:

Brain Pathway, Mother-Infant Bond Linked
Thursday, June 24, 2004

WASHINGTON (AP) - Newborn mice shriek frantically when mom's away - unless they have a defect in the same brain pathway that responds to morphine, says research that sheds new light on mother-infant bonding.

Beyond unraveling the biology of that most basic of bonds, the work also may offer new leads to better understand autism, a disorder characterized by poor social attachment, scientists from Italy's National Research Center report.

At issue is the brain's opioid system, best known for its role in pain, pleasure and addiction. Opioid drugs like morphine act on that system to block physical pain.

But there have long been clues that the pathway plays a role in some basic emotional pain, too, because giving morphine to animals can decrease their social behaviors.

Thus, one theory behind autism's symptom of social indifference is that the brain might be incapable of forming strong social bonds without feedback from its opioid reward system - like the pleasure a baby should feel from loving parental care.

To test that, Italian neuroscientist Francesca D'Amato and colleagues bred mice to lack a crucial opioid receptor in the brain, and compared them to normal baby mice.

First, they separated the newborns from their mothers for short periods. Normally that sparks nonstop shrieking from the babies. But the opioid-deficient pups hardly cried, the researchers report in Friday's edition of the journal Science.

And while normal mice babies always chose the nest built by their own mother over another mother's bed, only about a third of the opioid-deficient babies did. [...]

The researchers showed that mice who are lacking the gene needed to make a particular opiate receptor do not exhibit normal attachment behaviors.  The receptor is the part of the nerve cell that detects the presence of the endogenous (coming from within) opiate, and causes the nerve cell to respond.  For an introduction to the neurochemistry or receptors (and a lot more), you can download the primer, Brain Facts,  from the Society for Neuroscience website.  (The link takes you to the download page.  The download itself is 984KB.)

The term opiate  refers to a chemical that acts like morphine, which originally was derived from the opium poppy.  The term endorphin  refers chemicals, that are naturally found in the brain, that act like morphine.  Endorphin  is a portmanteau  of endogenous  and morphine.  Opiates and endorphins are not the only brain chemicals that are involved in the attachment process. 

Oxytocin  and vasopressin  are two hormones that are released in large quantities during childbirth.  It has been postulated that they play a role in maternal-infant bonding.  More specifically, they appear to heighten the acuity of memory to certain stimuli, such as the exact smell of the baby and the exact sound of its cry. 

I remember when I was a fourth-year medical student, spending a month in a pediatric hospital, on a unit that cared for infants.  Usually, there were 15 to 20 babies there at any time, and usually at least 5 or 6 were crying.  As a result, there was a constant din of babies crying.  It literally never stopped.  Like a person living near the ocean, one soon learns to tune it out, at least on a conscious level.  On an unconscious level, it still grates on the nerves. 

From time to time, I would be talking with one of the mothers, out in the hallway.  Invariably, within a few minutes, she would suddenly stop, hold up a finger, and say, "That one is mine."  Somehow, she had discerned the sound of her own baby's cry out of the mind-numbing cacophony.  I saw this dozens of times, and it amazed me every time.  When I tell this to women who have had babies of their own, they just give me that pitiful "of course you don't understand, you're a man" look.  It is true.  I don't understand.

Back to the topic at hand.  There is evidence for other brain chemicals playing a role in the attachment process.  See this  (45KB PDF)  paper for a review. 

Beyond the basic science, there is some clinical application to all of this.  There is a pharmaceutical product, ReVia  (naltrexone) blocks opiate receptors.  It is used to help persons with chemical dependency refrain from using.  It originally was marketed to help reduce craving for alcohol in alcoholics.  It also has been used, with some success, for addiction to opiates  such as heroin, Vicodin, etc. 

Another clinical use for naltrexone is to reduce repetitive self-injury.  Although no one really knows why some people cut or burn themselves over and over, the theory is that the self-injurious behavior causes the brain to release endorphins, and the experience of endorphin release rewards the behavior.  For some people, naltrexone can help them stop hurting themselves.  Likewise, naltrexone can reduce the frequency of gambling, and bingeing/purging (in patients with eating disorders).

Readers with an insatiable appetite for the clinical relevance of neurochemistry, especially as it relates to attachment, may want to read this article by the guru of PTSD, Bessel van der Kolk.  The Compulsion to Repeat the Trauma is a pretty dense article about attachment gone awry.  The basic idea is that people who have been traumatized form an attachment to the perpetrator of the trauma, and may even develop a tendency to do things to repeat the trauma.  If you don't want to read the entire thing, here are the last two paragraphs:

The "opponent process theory of acquired motivation" explains how fear may become a pleasurable sensation and that "the laws of social attachment may be identical to those of drug addiction." Victims can become addicted to their victimizers; social contact may activate endogenous opioid systems, alleviating separation distress and strengthening social bonds. High levels of social stress activate opioid systems as well. Vietnam veterans with PTSD show opioid-mediated reduction in pain perception after re-exposure to a traumatic stimulus. Thus re-exposure to stress can have the same effect as taking exogenous opioids, providing a similar relief from stress.

Childhood abuse and neglect enhance long-term hyperarousal and decreased modulation of strong affect states. Abused children may require much higher external stimulation to affect the endogenous opioid system for soothing than when the biologic concomitants of comfort are easily activated by conditioned responses based on good early caregiving experiences. Victimized people may neutralize their hyperarousal by a variety of addictive behaviors, including compulsive re-exposure to victimization of self and others. Gaining control over one's current life, rather than repeating trauma in action, mood, or somatic states, is the goal of treatment. The only reason to uncover traumatic material is to gain conscious control over unbidden re-experiences or re-enactments. The presence of strong attachments provides people with the security necessary to explore their life experiences and to interrupt the inner or social isolation that keeps them stuck in repetitive patterns. In contrast with victimized children, adults can learn to protect themselves and make conscious choices about not engaging in relationships or behaviors that are harmful.


I think it is important to note that there is a lot of evidence that the neurochemistry of the endorphin system is involved in attachment, as well as in the response to trauma and the development of repetitive self-injurious behaviors.  However, the way this actually works in humans is still speculative. 


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Sunday, June 20, 2004

Does God Belong on the Stump?
Why Politicians Are Not Mathematicians

There is an interesting article posted at the Ethics and Public Policy Center.  It was first posted in December 2000, but from the content, it sounds as though is was written before the 2000 election.  Yes, it is old, by political standards; but it is not yesterday's newspaper.  It is just as pertinent today as it was before the 2000 election.  I've selected some excerpts of general interest.  I then refer back to another "old" paper,  Mathematical Devices for Getting a Fair Share, first published in July 2000.  The original was in American Scientist, which requires a paid subscription.  Fortunately, the author (Dr. Theodore Hill) posted a copy on his web site.  In this post, I point out a curious connection between religion-in-politics and mathematics-in-politics, show why neither is commonly pursued in a rigorous fashion in political arenas, and show how the two can lead to the same kind of solution to social problems.  Unfortunately, this also demonstrates why the best solution -- whether religious or mathematical -- is rarely feasible in a competitive political process.

Does God Belong on the Stump?
A Conversation with Stephen Carter, Charles Krauthammer, and Leo Ribuffo
Posted: Saturday, December 2, 2000

[...] One is that for me as a voter, if a candidate wants to speak about his religion, that suggests to me that he wants me to think that religion is a relevant criterion, that I am learning something about him because I am learning something about his religion. The information I would like to be getting is, “This is an important part of me. It helps form who I am, and therefore, when I reason about the world and about important issues of public policy, my religious faith is a part of my reasoning process.” I think that a candidate who is going to talk about his own faith owes us more than just saying, “Isn't it neat that I'm a religious guy?” That candidate owes us at least some discussion of how his faith affects his thinking about public issues, because only in that way can we judge its relevance. Now, one might object that to make candidates tell us how their faith affects their reasoning gets far too deeply into the personal, protected sphere of religion. If that is so, then they shouldn't talk about it in the first place. The candidate who says his religious faith matters ought to give us some idea of how it matters.

[...]  The one that most interests me at the moment is that he felt a Christian party would be an oxymoron. Why? Because if it were truly Christian, he said, it would preach the entire gospel -- even the hard parts -- and therefore get no votes. If it were truly a party wanting to win, it would craft a kind of modified gospel, emphasizing some parts, omitting or muting others, compromising the purity of the faith in order to prevail in the election, and then it would not be truly Christian. He thought this would be a very bad thing. I agree that it is a very bad thing, and it is what tends to happen.

Later in the article, Leo Ribuffo -- a professor of History -- gives us an overview of the religious leanings of several dead presidents, such as the following, which reminds us of the influence of Deism  in early American politics:

The controversy over the religion of the Founders could be clarified if we could decide what we mean by the Founders. The American Revolution was won by an odd coalition. It was supported disproportionately by deist Enlightenment figures on the one hand and early evangelicals, the heirs to the First Great Awakening, on the other. It seems to me that the Constitution reflects a compromise between those groups. Lieberman said that the First Amendment was not intended to protect people from religion. Well, it might depend on which of the Founders you asked. Some surely would have believed that it was intended to do that. This is the exception I referred to earlier.

Of the deist-influenced Founders, Washington was among the most conventionally religious and started our tradition of civil religion, adding to the presidential oath, for example, “So help me God.” The least conventional was Thomas Jefferson, who said that he was a true Christian, by which he meant a follower of the ideals of Christ stripped of the mythology. Jefferson was a founder of the Democratic Party, which from the outset was more religiously diverse and more secular than its Federalist, Whig, or Republican foes.

Another interesting reminder is this:

It was Richard Nixon, not Carter or Reagan, who brought an overtly partisan religiosity back to the White House. He was a Quaker, raised with substantial doses of evangelicalism, and by the time he was an adult he had put together his own religious mix of Norman Vincent Peale's positive thinking plus Billy Graham's evangelicalism. It might seem incongruous, but it was no more so than most Americans' versions of Protestantism. Nixon accepted Graham's open endorsement in 1972, held religious services in the White House, and used religious connections to underscore support for what he liked to call “square America.”

The reference to Nixon reminds us that claims of religiosity are no guarantee against unethical behavior.  On second thought, maybe that is not significant: we hardly need a reminder of that.  On the other hand, claims of religiosity to not guarantee unethical behavior:

Carter was a sophisticated lay theologian, a born-again Baptist, mostly liberal in his theology, and seriously influenced by neo-orthodox theologian Reinhold Niebuhr, who warned that individuals and nations should beware of the sin of pride. Yet he was presented over and over as a holy roller from Hicksville. And that partly explains why he appeared in Playboy. The official explanation was that he was trying to explain the sin of pride to the ungodly. In fact, he was trying to show a cosmopolitan audience that he was not just a hick. There was an uproar of unimaginable proportions. The wisest response in my view came from Martin Luther King, Sr.: to Carter's remark that he had lusted in his heart, King replied, “They can't kill you for looking.” Carter's famous “malaise” speech is, in fact, an interesting Niebuhrian attempt to call Americans back from their pride and their greed.

See this  for a review of Niebuhrian theology, and this  for a copy of Carter's speech.  Carter was a sincerely religious man, but he lost.  This brings me to my point: people don't want to be called back from their pride and their greed

Everybody loves a winner, and the American stereotype is that winners are proud.  The American tradition is this: to the victor belongs the spoils.  The winner-take-all philosophy is perhaps the most important distinction between American political though and that of Europe, where an expectation of compromise is the starting point for negotiations.  We Americans often look down on our European cousins for their quaint, outmoded ways.

 As it happens, though, the notion of compromise is quaint, indeed, but it also has a solid mathematical foundation.  The paper that demonstrates this is available as a 83KB PDF file.  The illustrations are contained in a separate .tar compressed file, which is almost 50MB.

Mathematical Devices for Getting a Fair Share
by Theodore P. Hill
Volume 88, No. 4
July-August 2000

Since the dawn of history man has bickered and battled over fair distribution of resources, dividing estates, territories and the spoils of war. Through the ages such dilemmas were typically resolved unilaterally by kings (Solomon and the baby), by judges or simply by force, and few truly logical solution methods evolved. In the last fifty years, however, a number of mathematical devices have been discovered which other elegant, practical, and often surprisingly simple resolutions to many fair-division problems.

The oldest known written fair-division problem is an estate-division issue from the 2nd century AD Babylonian Talmud (Figure 1). A man dies owing 100, 200, and 300 zuz to each of three claimants, A, B, and C respectively. In most modern bankruptcy proceedings the claimants receive shares of the estate proportional to their individual claims, no matter what the size of the estate. In the Talmudic problem, A would always receive one-sixth of the total estate, B one-third, and C one-half. The solution presented in the Talmud is also this proportional one if the total estate value is 300 zuz (see Figure 1), but if the estate is only 100 zuz, each claimant receives equal shares. And even more curiously, if the estate is 200, then A receives 50 and B and C receive equal amounts of 75 each, even though their claims are not equal.

The logic of the Talmudic solution remained mysterious until 1984 when Israeli mathematicians Aumann and Maschler discovered that these seemingly inconsistent settlement methods actually anticipated the modern “nucleolus” solution of a single 3-person cooperative game. Roughly speaking, the nucleolus is that solution which minimizes the largest dissatisfaction among all possible coalitions. [...] [emphasis mine]

The Corpus Callosum is fond of making connections.  What is the connection between religion-in-politics and mathematics-in-politics?  The article, Does God Belong on the Stump?, makes the point that "if it [a Christian party] were truly Christian, he said, it would preach the entire gospel -- even the hard parts -- and therefore get no votes."  And the article, Mathematical Devices for Getting a Fair Share, makes the point that the logical solution to fair-division problems is the solution that "minimizes the largest dissatisfaction among all possible coalitions."  Yet, a politician who followed this method would get no votes.  He or she would not be perceived as a winner, in the American stereotype.  Fair-division problems are common in politics, but the truly fair solutions don't make anyone especially happy; instead, they minimize unhappiness.  This is one reason that politicians are not mathematicians.

The other reason is that most politicians are not smart enough to understand this kind of thing.  (Al Gore was, but he lost.)  Jimmy Carter's "malaise" speech was characterized as an effort to "call Americans back from their pride and their greed."  In other words, it was an attempt to introduce fairness into the political process.  By advocating a limit on energy imports, he also was advocating a society of mutual sacrifice.  No one was interested.  Such limits would minimize the number of persons who would loose out, but it would create no winners. 

Carter's notion was not based upon a mathematically rigorous fair-division solution; rather, it was based upon a Biblical motion of modesty.  As it happens, both the Talmudic fair-division approach, and the Biblical repudiation of greed, lead to roughly the same outcome: no clear winners, but no big losers. 

Is that such a bad thing?  Apparently, American voters think it is.


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