Common Genes Tied To Alcohol, Nicotine, Cocaine Addictions

[FrostyMcFailure]

Common Genes Tied To Alcohol, Nicotine, Cocaine Addictions



ScienceDaily (Mar. 16, 2009) — For decades, finding clues to substance addiction has been much like searching for a needle in a haystack. But researchers may finally be honing in on specific genes tied to all types of addictions - and finding that some of the same genes associated with alcohol dependence are also closely linked with addictions to nicotine, cocaine, opoids, heroin and other substances.

In a new landmark paper to be published in the April 2009 issue of Nature Reviews Genetics, addiction experts at the University of Virginia Health System and the University of Michigan present new insights into the significant progress made within the last several years in understanding the genetics of addiction.

"Addiction researchers have found that several genes are linked with multiple addictions," says co-author Ming Li, Ph.D., professor of psychiatry and neurobehavioral sciences at the UVA School of Medicine. "So, we're narrowing the scope to specific genetic targets. Once researchers can pinpoint exact genetic variants and molecular mechanisms, then we can create much more effective, even personalized, treatments for individuals addicted to a variety of substances."

In the paper, which in part serves as a comprehensive guide to the existing body of addiction genetics research, Li and co-author Margit Burmeister, Ph.D., professor of psychiatry and human genetics at the University of Michigan, present a summary of specific genomic locations on 11 chromosomes where addictions to alcohol, cannabis, cocaine, heroin, nicotine and opoids are clustered together.

"The comparison of peaks for addictions to multiple substances on certain chromosomal locations confirms that genetic vulnerability to different substances overlaps, in part," Li says. He further points out that variants in several genes, including aldehyde dehydrogenases, GABRA2, ANKK1, and neurexins 1 and 3, have already been associated with addictions to multiple drugs.

In recommending a future direction for research into the genetics of addiction, Li suggests focusing on CHRNA5, CHRNA3 and CHRNB4 clusters, among other variants. "The exact nature of the gene variants and how they function are still unknown, so functional studies as well as studies using additional ethnic population samples may be quite revealing."

link

 

[MyDoorsAreOpen]

^ I'm interested in the ethnic population sample studies. I think they're going to find that some populations, that have a millennia-long history of integrating moderate alcohol use into their cultures, have largely selected out these genotypes from their population, while ones that weren't exposed to alcohol until sometime in the past 1000 years or less still have it in significant numbers.

In other words, I think they're going to find that some ethnic groups are just more prone to addiction than others, and it's not attributable to family dynamics or attitude toward drugs.

 

[Hammilton]

I agree. I would be surprised if Native American's do not have issues with the gene that codes for alcohol dehydrogenase.

GABRA2 is surprising. I would have thought GABRA1, as I had thought GABRA2 was much less tied in with drugs of abuse.

 

[Enlitx]

^ I'm interested in the ethnic population sample studies. I think they're going to find that some populations, that have a millennia-long history of integrating moderate alcohol use into their cultures, have largely selected out these genotypes from their population, while ones that weren't exposed to alcohol until sometime in the past 1000 years or less still have it in significant numbers.

In other words, I think they're going to find that some ethnic groups are just more prone to addiction than others, and it's not attributable to family dynamics or attitude toward drugs.

Do you really think the time that ethanol has been available to entire cultures has been sufficient to account for a significant amount of negative selection? It think that you might see a slight variation in the genetics in cultures that have had alcohol for a while, I am just curious exactly how much selection has played a role thus far.

 

[MyDoorsAreOpen]

Sure. People in the Fertile Crescent and the Mediterranean made alcohol for making water fit to drink. This could definitely select against people who couldn't tolerate, didn't like, or had a tendency to abuse, alcohol, since the only other option was drinking water that wasn't disinfected, and probably not live too long after that. Today, non-Muslim people in this region are all known for drinking small amounts of alcohol frequently, and seeing low rates of abuse.

The Indians, Himalayan indigenous people, and Chinese were graced with the tea plant, which they used instead of alcohol to purify water. I think this explains why alcohol is not nearly as much a part of these places' social cultures, and why a gene for poor metabolism of ethanol wasn't weeded out of these populations.

 

[slimvictor]

One thing I am scared of is this:
ignorant people (probably in the media, but possibly in the US Government Office against Drugs, acronym GOD) might take this as proof of the "marijuana is a gateway drug" theory - nevermind the fact that it has already been disproved.

 

[Mr Blonde]

^ How so? I don't see cannabis mentioned at all in the article, and we all know that authorities don't need proof to make foolish claims.

 

[qwe]

^ I'm interested in the ethnic population sample studies. I think they're going to find that some populations, that have a millennia-long history of integrating moderate alcohol use into their cultures, have largely selected out these genotypes from their population, while ones that weren't exposed to alcohol until sometime in the past 1000 years or less still have it in significant numbers.

In other words, I think they're going to find that some ethnic groups are just more prone to addiction than others, and it's not attributable to family dynamics or attitude toward drugs.

you sure overdose rates are high enough to cause significant gene changes even over 1000s of years? i don't think a high enough percentage of addicts/users die from overdose

i think different rates between ethnicities would be there just because they have somewhat different genetic backgrounds going so far. how big of a change are in DNA do you think would occur?

 

[MyDoorsAreOpen]

^ Now I'm out of my element.

I was mostly thinking of people drinking bacteria-infected water and dying of sepsis, because they couldn't mix it with a little alcohol, either because A) They didn't tolerate the alcohol well, or B) They were given to abusing it and causing problems, and so were sanctioned by either other people or themselves to drinking water without it.

 

[GTnV]

I think I've got a gene they haven't found, I like a different drug every day!

Seriously though, anyone have a link to this actual paper? I'm always skeptical about studies of this nature.......

 

[habboz]

^ I'm interested in the ethnic population sample studies. I think they're going to find that some populations, that have a millennia-long history of integrating moderate alcohol use into their cultures, have largely selected out these genotypes from their population, while ones that weren't exposed to alcohol until sometime in the past 1000 years or less still have it in significant numbers.

In other words, I think they're going to find that some ethnic groups are just more prone to addiction than others, and it's not attributable to family dynamics or attitude toward drugs.

This is true but ive also heard somewhere i forget were...that morphine used to be used often also and has been used for a long time. :D - oh and cocaine leaves have been chewed by the people in south america for a long time i heard also so poeple have been using drugs personally forever just different ones from the looks of it.

 

[qwe]

^ Now I'm out of my element.

I was mostly thinking of people drinking bacteria-infected water and dying of sepsis, because they couldn't mix it with a little alcohol, either because A) They didn't tolerate the alcohol well, or B) They were given to abusing it and causing problems, and so were sanctioned by either other people or themselves to drinking water without it.

ah i see. i didnt take into account alcohol's benefits with disease. that's a good point, now we may have enough death for a little bit of genetic change to occur

 

[Hammilton]

It doesn't matter if they'd died because of disease or not.

What matters is whether they had kids before they died. The majority will have passed their genes on before any OD or other death.