April 29, 2012
Weak Orbitofrontal Cortex Leads To Teen Drug Abuse
Many brain scan studies that have found relationships between substance abuse problems and brain activity started too late (after the abuse has started) to identify whether differences were causes or results of the substance abuse. Now a study that started with 14-year-olds find that teens with a weak orbitofrontal cortex are more impulsive and more likely to start using drugs and alcohol at an earlier age.
Why do some teenagers start smoking or experimenting with drugs—while others don't?
In the largest imaging study of the human brain ever conducted—involving 1,896 14-year-olds—scientists have discovered a number of previously unknown networks that go a long way toward an answer.
Robert Whelan and Hugh Garavan of the University of Vermont, along with a large group of international colleagues, report that differences in these networks provide strong evidence that some teenagers are at higher risk for drug and alcohol experimentation—simply because their brains work differently, making them more impulsive.
Their findings are presented in the journal Nature Neuroscience, published online April 29, 2012.
This discovery helps answer a long-standing chicken-or-egg question about whether certain brain patterns come before drug use—or are caused by it.
"The differences in these networks seem to precede drug use," says Garavan, Whelan's colleague in UVM's psychiatry department, who also served as the principal investigator of the Irish component of a large European research project, called IMAGEN, that gathered the data about the teens in the new study.
I bet in 5 years we'll know genetic variants that control the strength of the orbitofrontal cortex. My guess is that once it becomes possible for parents to choose genetic variants for their offspring that they'll choose genetic variants for a strong orbitofrontal cortex. Therefore the human race will become much less impulsive. Overall this will be a good thing. Though it might make for less creativity in some situations. Perhaps other genetic variants for creativity will be chosen and we'll get much more creative future humans anyway.
Suppose brain scans can identify the more impulsive. Should something be done to reduce their opportunities for use of illegal drugs, cigarettes, and alcohol? Imagine an implant that filters certain drugs out of the body. Or an implant that alerts others that the kid is on nicotine or cocaine.
In a key finding, diminished activity in a network involving the "orbitofrontal cortex" is associated with experimentation with alcohol, cigarettes and illegal drugs in early adolescence.
"These networks are not working as well for some kids as for others," says Whelan, making them more impulsive.
Faced with a choice about smoking or drinking, the 14-year-old with a less functional impulse-regulating network will be more likely to say, "yeah, gimme, gimme, gimme!" says Garavan, "and this other kid is saying, 'no, I'm not going to do that.'"
"Honey, our embryo has a low Wisdom score, can we roll again?"
"Hell no, look at that potential Charisma. Our baby's gonna be a movie star!"
"Sure, her and 75 million other Charisma 18s in her cohort. I weep for humanity."
Is there a way to stimulate the orbitofrontal cortex - perhaps with the insertion of electrodes? If so could that prevent dangerous addictive behaviors? Could stimulating the orbitofrontal cortex stop dangerous addictive behavior?
If we could prevent dangerous additive behavior would we allow society to test all children and then make a decision on treatment or would we defer the judgement to parents? I prefer the latter especially if the cost of test and treatment is not borne by the family.
In the case of current addicts I would say we have a legal right to do everything morally possible to stop the addict's misbehavior. The important question revolves around your definition of moral. What should we be allowed to do to stop addiction?
Which brings up a concern - I doubt that orbitofrontal cortex shortcomings are the sole reason someone becomes an addict. It may be a significant reason even an decisive factor in many cases but, in my limited understanding, people become addicts for a variety of reasons. Eliminating a "weak" orbitofrontal cortex may not stop all addiction.
If a test revealed stimulating the cortex stopped 1% of addict cases maybe that is not worth it. It it stopped 10% maybe it is.
Randall, you are throwing around three very different terms interchangably: experimentation, use, and abuse. It's easy to confuse use and abuse in America because drugs are illegal, and the drug education industry encourages us to do so. But it makes us lazy, especially when trying to define whatever problem is associated with drugs.
Contrast with alcohol, which has a far better delineation between use (which is condoned and in fact encouraged by advertisers) and abuse (which is not). Note that the article only addresses experimentation and use, not abuse. But this article doesn't really shed any light on what makes experimentation and use evolve into abuse.
Only in teenagers? So after the teenager grows up, are they still more impulsive and start doing other stuff?
It's better that teen drugs are abused. Those adult drugs are the real killers.
The title of this posting is very misleading. Does the research actually demonstrate this? The answer is no, and this is why this is a long term study. This is merely what they are hoping to find is true.
Hugh Garavan, an associate professor of psychiatry and psychology at UVM, and senior author of the paper, and Robert Whelan, a post doctoral researcher at UVM in the department of psychiatry and psychology, and lead researcher on the study. The two appeared on the VPR program "Vermont Edition." I called into that radio program and made several points about the research into the epigenetic causes of both addiction and depression by Dr Eric J Nestler from Sinai Medical Center. You can the interview in its entirety here:
I will post the references for my phone comments here: "Montitor on Psychology" a publication of the American Psychological Association Sept. '11, says, studies are finding that 46% of surveyed students report feeling "hopeless," 31% reported feeling so depressed that it was difficult to function. In 2010 a national survey that 44% of the student that seek help from college counseling center had "serve psychological problems," which into suicidal thoughts, depression, self injury, and alcohol abuse. It also reported that all of these reported issues were increasing, with clients struggling with alcohol abuse rising 45.7%.
In the Dec. '11 issue of Scientific American, Eric J Nestler of the Sinai Medical Center, author of the article "Hidden Switches in the Brain" discussed studies that demonstrate a role for long lasting epigenetic modification in such disorders as addiction and depression. Epigenetic changes can also affect maternal behaviors in ways that reproduce the same behaviors in the offspring.
There are a high number of variables in any research and the caution here is that we should not be looking for a single "cause." What Nestler's research demonstrate is a possible way to view and measure one type of change that occurs in affected individuals.