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The Wisdom of Psychopaths
In this engrossing journey into the lives of psychopaths and their infamously crafty behaviors, the renowned psychologist Kevin Dutton reveals that there is a...
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John has a few snorts of cocaine, finds he can take it or leave it, and never bothers to take another hit. Jim has a few snorts of cocaine and before he knows it, his whole life revolves around getting more of the white powder, until his job, his marriage, his health are gone. Why? The answer may lie in one of the most exciting neuroscience discoveries of the last fifty years: the finding that new neurons are born in the adult brain.
During the past decade we’ve learned a lot about the function of these newborn neurons, revealing their possible role in psychiatric and neurological diseases such as mood disorders, schizophrenia and epilepsy. The promise of this research is extraordinary. We may be on the verge of understanding, treating or even preventing life-crushing brain-based diseases — including one that affects an estimated 23 million Americans: drug and alcohol addiction.
In a recent study published in the Journal of Neuroscience, Michele Noonan, a University of Texas neuroscience graduate student in the lab of Amelia Eisch, shows that a lack of neurogenesis, or birth of new neurons, in the adult rat can actually cause drug addiction. Their team blocked neurogenesis in the hippocampus — a seat of memory — with targeted irradiation, and then tested the rats for their ability to become addicted to cocaine. They found that when fewer neurons were born in the irradiated hippocampus, rats were more vulnerable to develop cocaine addiction and were more likely to relapse. This is the strongest evidence yet that there are real biological reasons why some people might be more vulnerable to addiction than others, and gives us a better understanding of the role these little newborn neurons might play in the brain.
Neuroscience research on addiction has largely focused on the role of reward centers in the brain, and increasingly, the role of the hippocampus. In light of the discovery that new neurons are born in the hippocampus, recent studies have sought to understand how adult neurogenesis could be involved in addiction. Studies have shown many tantalizing correlations between neurogenesis in the hippocampus and addiction. Drugs of abuse such as cocaine can regulate adult neurogenesis. Enriched environments, antidepressants, and exercise -- all known to increase neurogenesis — are also associated with decreased drug taking and relapse. Stress and schizophrenia — known to decrease neurogenesis — are associated with increased drug taking and relapse. But until now, the causative link between adult neurogenesis and addiction has not been shown.
There have been clues, however. Much of the work (and debate) on neurogenesis and disease has focused on the function of newborn neurons in mood disorders such as depression. This has been a rich and controversial field, with conflicting reports and promises of imminent cures. The most convincing studies have shown a connection between stress, neurogenesis and depression: Stress can decrease neurogenesis, and antidepressants can increase neurogenesis. Such work has led to the compelling and yet still controversial “neurogenesis hypothesis for depression.” Could such a relatively tiny population of newborn neurons in the hippocampus be responsible for so much?
It has been notoriously challenging to test the function of newborn neurons because it is difficult to manipulate newborn neurons without perturbing the existing hippocampal network. Noonan et al overcame this problem by selectively irradiating the hippocampus of rats, inhibiting neurogenesis only in the hippocampus with no effect on the adult neurons or the overall network architecture and function. The rats with reduced neurogenesis in hippocampus became more addicted to cocaine than a control group: they pressed the lever for cocaine more often and more frequently, and became willing to press the lever more times for a single dose than the controls. After they became addicted, the rats went through a month of forced withdrawal, and their drug seeking behaviors were assessed. Rats with decreased neurogenesis were almost twice as likely to relapse, pointing to an interesting connection between learning and memory and addiction.
It is not surprising that addiction can be traced to an area of the brain that controls learning and memory as well as reward. This is certainly a rich and complex area of research, with emotional memory apparently centered in one particular region of the hippocampus, the ventral hippocampus. Could the newborn neurons be few in number but particularly powerful because they have a separate function from their adult counterparts? Could they shape what we remember as rewarding?
Stress has been shown to be a risk factor for addiction; perhaps the discomfort of stress motivates drug taking. But interestingly, in this study the rats did not have an increased stress response, or any evidence of other symptoms related to mood disorders, such as depression or anxiety. The authors conclude that there is a direct connection between neurogenesis and addiction, one that does not necessarily involve stress, and it could be the tipping point, increasing the vulnerability to addiction in one person rather than another.
Based on their results and evidence from other studies on addiction and the hippocampus, the authors suggest an intriguing explanation for addiction: newborn neurons in the hippocampus inhibit the release of dopamine, one of the major chemical messengers that act as a reward signal. Thus, with fewer young neurons in the irradiated rats, more dopamine is released when cocaine is administered. With more reward signal they are more likely to become addicted and have an exaggerated memory of reward associated with taking cocaine. Thus, with an overblown feeling of reward and memory of reward in the absence of the dopamine-dampening newborn neurons, there is an increased risk of relapse. Thus this study suggests a new and intriguing role for newborn neurons in the hippocampus, lighting the way for future studies on addiction.
It also raises an enticing prospect: Some day, when we can test for the birth of these new neurons, an addiction-prone person like Jim may not have to wonder anymore whether it’s safe to take that first hit of cocaine. He’ll know that his level of neurogenesis signals clearly: that way lies disaster.
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27 Comments
Add CommentI hope one day there will be away to take cravings for nicotine and pot etc,etc away without the use of bug drugs like pins and pans, they don't work anyway. The patch works but is to expensive. If the government ment what they say about helping people then they ought to give the patch for free, under the condition they attend a support group once a week for 6 months after that the patient pays for half. I would be there in a drop of a dime. Maybe one day the brains will create a patch with the nanochemisrty required to replace the receptors that stimulate the addiction.
Reply | Report Abuse | Link to thisThe final paragraph states:
Reply | Report Abuse | Link to this"It also raises an enticing prospect: Some day, when we can test for the birth of these new neurons, an addiction-prone person like Jim may not have to wonder anymore whether it’s safe to take that first hit of cocaine. He’ll know that his level of neurogenesis signals clearly: that way lies disaster."
If that's all we can learn from this research let's just skip it: the correct answer is that it's always a bad idea to take that first hit of cocaine - just say no.
Ignoring the author's apparent ignorance, this is very interesting research into the physiology of addiction. It might help the medical community understand the brain physiology leading people to initially pursue addictive activities. It would be interesting to test for an association between neurogenesis and eating disorders, for example.
But it seems likely that the biological function of neurogenesis is not to simply inhibit the release of dopamine. It would seem those new neurons would eventually be employed somehow in within the brain’s neural networks. It would be very interesting to determine how new neurons are employed within the brain. Is neurogenesis related to recovery from injury, disease or aging? Do those with lower production of new neurons suffer in short term memory? These questions not relating to addiction are also very interesting.
create nanochemical that block the persons addiction. Smoking is my thorn, Leave stress out of it as it is created by systems to control the masses, and dosn't have nothing to do with addiction. Addictions start out as social norms. The fashion was accepted by royalty and when they couldnt control it they made it illegal, by then the population was hooked and proceeded to procreate addicts. Addicts are born from these systems and war.
Reply | Report Abuse | Link to thisjtdwyer, well if drugs couldn't get a person addicted... then using them occasionally wouldn't be as much of a problem.
Reply | Report Abuse | Link to thisCertainly it is a novel approach to fighting the silly "War on Drugs" which is a total failure.
All drugs should be legalized, with drugs like Pot available through already licensed alcohol stores, and hard drugs available through government outlets.
1) The chances of bad needles and overdose would be greatly reduced.
2) The government wouldn't push drugs to kids using other kids right in their neighborhoods/schools, which would be a major help right off the bat.
3) The drug center could have educational and rehab programs integrated
4) All the money currently spent getting people killed though anti-drug law enforcement could be spent on education/rehab., as could the bulk of any revenues from the drug sales.
5) The drug cartels would go out of business or at least seriously decline in power.
6) Our prisons would stop overflowing with drug related arrests, giving lots of people a better chance at a better life.
The fact that this approach is not even considered as a serious possible solution in the US points to extremely strong bias that is preventing people from honestly weighing cost/benefits of our approach.
Our mainstream narrow mindedness has led us to a pretty disasterous policy in which the worse it works, the more we escalate it. We need to take control of the complete cycle in order to begin to break it.
tharriss - I became sympathetic to this approach since my tour of duty in Viet Nam but then, in mid-1970, the CIA made a deal with the montagnard (moutain) tribesmen to attack North Vietnamese on the Ho Chi Min Trail, in exchange for their being allowed to run drugs into South Viet Nam. Within a couple of months around 30% (based on official estimates) of all (especially conscripted) servicemen U.S. their became addicted to 98% pure heroin.
Reply | Report Abuse | Link to thisAs a result of this significant direct experience, I strongly object to the idea of legalizing addictive drugs like the U.S. did in Viet Nam.
Even if the addictive process was defeated for all drugs, the debilitating effects of even purely recreational use of most such drugs, if easily and legally available, would still be devastating to individuals and society. I doubt the risk of overdose would be diminished: it might even increase unless a magic bullet for it were found, dramatically increasing other detrimental effects. Making syringes easily available to addicts would accomplish public health objectives.
Hallucinogenic drugs, while not generally addictive, are at best temporarily debilitating and can be permanently so.
So, I can only disagree with most of your suggestions.
However, having spent nearly 2 years on chemo in the past five and suffered severe anemia compounded by a heart condition, I most certainly would support at the very least
the medical use of marijuana.
Moreover, especially recalling much earlier days overseas, I do agree that the effects of marijuana use are the least problematic both individually and socially of any recreational drug, including alcohol. I'd have to personally agree that it should be legalized for adult use.
That step alone would likely significantly reduce almost all the many problems caused by illegal drug use, including it availability to children, violent commercial dealers and gangs, dangerous quality issues, etc., not to mention turning the government's management of drug use from a large expense to a profit center.
Legalized marijuana would also most likely reduce the incidence of violent behaviors often associated with alcohol use, probably including domestic violence and possibly even sex crimes.
Other, more dangerous drugs would remain dangerous even if they were not addictive.
Perhaps the editors might choose a different picture for the article next time. It's not very nice to give the readers the finger....just sayin....
Reply | Report Abuse | Link to thisThanks jtdwyer, while I appreciate your experience with the young people in the military in clearly stressful situations having that result in that case, I'm not sure it is fair to compare that experience to what would happen in a civilian setting, monitored in the way I was suggesting.
Reply | Report Abuse | Link to thisI agree that even if you can mitigate the addictive properties of hard drugs, they can still be dangerous... but I'd still rather have them sold by a licensed and monitored safe broker under safer conditions than how they are currently produced and sold, and without the direct marketing to children!
People are going to do drugs. They don't avoid them because they are illegal (in fact the opposite can be true). Better to make the safer, control their distribution, work on education and rehab more, and cut the legs out from under the drug cartels.
Since the current policy of making of hard drugs illegal is such a failure and has huge expenses and collateral damage for society, I'm amazed that more attention isn't paid the alternative of controlled legalization.
At any rate, I think a great place to start would be legalizing a popular soft drug like marijuana, and I think that would be a big step towards realizing a lot of the benefits I listed, even without yet addressing hard drugs. You have to start some place.
I must agree with tharriss, your experience in Viet Nam, although a terrible thing was happening, is no the same setting as recreational use in a functioning society. You may have gone through the war a strong person, but many people wanted to forget or relieve their mental/physical pain. It was easier to get 98% pure heroin, than most other drugs. I believe tharriss's point is the opposite of what you expierenced, controlled, educated use of what people will do ignorantly if they have to.
Reply | Report Abuse | Link to thisYou also say "Hallucinogenic drugs, while not generally addictive, are at best temporarily debilitating and can be permanently so."
'At best temporarily debilitating' is far from what science is starting to see working with these substances. Ibogamine can be used to treat and in cases cure heroin/alcohol/tobacco addiction (In the case of William Burroughs, it worked, not a steady regiment, but a session or two and that was it). Ibogamine is generally described as 30 years of psycho-therapy in 1 day. Science is just starting to study these things (outside of the scienfitic hindering USA). Halloucinogenic substances can open the mind as much as they can close it, it is in the EDUCATIONAL use of such things that is key. Slamming 5 hits of acid and going to a rock show might not turn out well for one person, but it doesn't mean that LSD doesn't have any scientific benifits. People will use it either way, why not prepare them as best we can?
My point isn't to say 'try these, they're good', but rather education is the way to better decisions, and saying these things are illegal just because doesn't educate or stop anyone from doing them.
Curious to me that a number of commentaries here, as on any article anywhere dealing with drug abuse, rail at the government to legalize drugs.
Reply | Report Abuse | Link to thisIf you focus on the pros/cons of legalizing drugs you are COMPLETELY missing the core problem. The core problem is addiction. Addicts destroy their lives and seriously affect the lives of those that love and care about them. That is what the laws are trying to prevent. It is not a question of denying freedom as much as it is a question of preventing self-destruction. I would rather treat addicts than jail them; but if they are unwilling to change and they become a danger to themselves or others, they have to be restrained somehow.
agenthucky - I also have quite a bit of experience living in the United States. In my experience people here are also under a great deal of stress. How can you dismiss that experiment in legalized addictive drugs as irrelevant? Do you think that U.S. soldiers were simply stressed out, ignorant and uneducated?
Reply | Report Abuse | Link to thisI found no mention of any methods that would provide for controlled, educated use of heroin, morphine or cocaine by the general population, even if it were not addictive, and cannot imagine any conditions that would render the general population "controlled and educated" in their use of drugs. Perhaps you'd like to share that information.
The article did not describe any method by which the rate of neurogenesis might be increased to render addictive drugs non-addictive. It only described that laboratory animals with disrupted neurogenesis were more susceptible to addiction.
Managing a society of only 'mildly addicted' recreational users of addictive drugs is a preposterous proposition.
I apologize for my role in misdirecting the constructive discussion of this article.
Reply | Report Abuse | Link to thisI certainly hope that this experimental result can help with the treatment of addictions, especially the most common addiction to food.
But it seems likely that the biological function of neurogenesis is not to simply inhibit the release of dopamine. It would seem those new neurons would eventually be employed somehow in within the brain’s neural networks. It would be very interesting to determine how new neurons are employed within the brain.
Is neurogenesis related to recovery from brain injury, disease or aging? Do those with lower production of new neurons suffer in short term memory? These questions not relating to addiction are also very interesting.
Here! Here!
Reply | Report Abuse | Link to thisUnfortunately, everyone from the government on down to local police agencies who have the authority to confiscate vehicles, homes, boats, etc., are making too much money from the war on drugs.
nice article...i think it would have been more informative to see what the results were with something like crack or meth....
Reply | Report Abuse | Link to thisRegarding the last paragraph- It's highly unlikely Jim would have been tested in the first place. If the theory proves to be factual a better use would be addiction treatment, not pretesting to see if using cocaine would make you addicted. I suspect the average person using illegal drugs would use them whether a test showed him/her to be addiction prone or not.
Reply | Report Abuse | Link to thisI think that people take the first drugs when they are depressed or under stress.
Reply | Report Abuse | Link to thisI agree it would be a disaster to legalize all drugs. If it was done, then no doubt unscrupulous drug companies would develop drugs that were even more addictive than heroin. Imagine the enormous profit there would be in it if the stuff could be sold over-the-counter? Well...for a few years any way, until most of the population was addicted and the economy collapsed and the country became a dysfunctional hellhole.
Reply | Report Abuse | Link to thisAlcohol is legal and you still find alcoholics. Addiction will exist whether you criminalize the drug or not...just saying.
Reply | Report Abuse | Link to thisAgain, sorry for any confusion I might have caused.
Reply | Report Abuse | Link to thisThe article did not describe any method by which the rate of neurogenesis might be increased to render addictive drugs non-addictive. It only described that laboratory animals with disrupted neurogenesis were more susceptible to addiction.
I suspect the only way that addictive drugs could be made non-addictive would be to prevent their causing effects such as increasing dopamine production. If this were done, I doubt anyone would be tempted to try them in the first place, since the experience would likely be very dull and unrewarding.
Non-addictive versions of addictive drugs could only be helpful in maintaining current addicts of those drugs. The use of methadone to treat heroin addiction, for example, has met with limited success.
When a mouse is stressed a little 'squirt' of iron is induced in the brain.
Reply | Report Abuse | Link to thisNeurite outgrowth has NOW been shown to be increased by iron chelators.
"Deferoxamine-induced neurite outgrowth and synapse formation
in postnatal rat dorsal root ganglion (DRG) cell cultures"
there are too much to adress about the "direct correlation" between neurogenesis and addiction.
Reply | Report Abuse | Link to thisQuote: I suspect the only way that addictive drugs could be made non-addictive would be to prevent their causing effects such as increasing dopamine production.
Reply | Report Abuse | Link to thisAnswer: What would be the significance of the raising of acetylcholine PREVENTING the addictive nature of the drug .. ?
"Acetylcholine enhancement in the nucleus accumbens prevents addictive behaviors of cocaine and morphine"
ironjustice - Since you didn't specify, I can't know where your quote came from. I don't find it in the main body text - perhaps some link?
Reply | Report Abuse | Link to thisNot being a biochemist but attempting to understand your point, I only find that acetylcholine is a neurotransmitter that is involved in the reward system and is associated with nicotine addiction, but I can't understand your point.
The main point of discussion, I think, was that some readers/commentators were under the impression that addictive drugs taken for 'recreational purposes' might be rendered non-addictive and therefore even more 'entertaining' as a result of this research.
My counterpoint is that any process that renders the drugs non-addictive will likely make them less pleasurable as well, also rendering them 'non-recreational'.
Quote:My counterpoint is that any process that renders the drugs non-addictive will likely make them less pleasurable as well, also rendering them 'non-recreational'.
Reply | Report Abuse | Link to thisAnswer: That is sorta the same as what I was thinking. IF these pathways are 'the' reason we do do stuff then if we screw with it maybe we will find that we don't enjoy reading a book as much or helping our neighbour etc.
We might be causing a world of apathy ..
As to the mention of acetylcholine it comes from a medical study. I find anything in quotes can usually be found with a simple search of Google. The choline nicotine lithium connection is somehow involved in the addiction.
ironjustice - I understand now, and agree - thanks.
Reply | Report Abuse | Link to thisEditors: There have been some good articles recently discussing the linguistic limitations and ambiguities of the English language, but once again I have to comment about an article title.
Reply | Report Abuse | Link to thisWhile no commentator has mentioned it, the title "Can Newborn Neurons Prevent Addiction?" can be interpreted to indicate that placental neurons are being used experimentally to treat addiction.
Considering the outrage over the experimental use of placental stem cells, this inference should be avoided at all costs. I suggest, for example and for future reference, that 'Can New Neuron Production Prevent Addiction' should have been used.
Quote: Maybe one day the brains will create a patch with the nanochemisrty required to replace the receptors that stimulate the addiction.
Reply | Report Abuse | Link to thisAnswer: It already has. Lecithin has been shown to treat addiction in Calcutta and iron chelators INDUCE neurogenesis. So since iron selectively destroys lecithin / phosphatidylcholine one might wonder whether the REMOVAL of the iron would kill two birds with one stone. Neurogenesis AND increase of lecithin because iron is not there to destroy it.
http://tinyurl.com/2y3pfn
"Of 200 addicts treated in the Hospital for
Tropical Diseases, Calcutta, 70% were cured."
ironjustice - Interesting study, although as inferred the traditional opium eaters of India can be considered to have a bad habit compared to those smoking or injecting narcotics. It seems the did have a large sample population to experiment with, lending credibility to their work. Additional study with crack smokers in the U.S. would offer a more stringent test of this or a derived method. Thanks.
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