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The new findings offer insights into the genetic factors that underlie this phenomenon, and other potentially related health risks. Credit: Neuroscience News

Genetic Links in Cannabis Use Disorder

Summary: Researchers analyzed over 1 million genomes, revealing insights into cannabis use disorder and its ties to psychiatric issues, other substance abuses, and lung cancer risks.

The study, part of the Million Veteran Program, identified genetic variants linked to cannabis use disorder and its associated health and behavioral problems. This largest-ever genome-wide study on cannabis disorder informs public health risks amid increasing marijuana use.

The findings highlight the importance of understanding the genetic basis of cannabis-related disorders to inform public health policies.

Key Facts:

  1. Researchers identified numerous genetic variants associated with cannabis use disorder, connecting it to other health and behavioral issues.
  2. The study suggests a potential link between cannabis use disorder and an elevated risk of lung cancer, though further research is needed.
  3. This comprehensive analysis is part of the U.S. Department of Veterans Affairs’ Million Veteran Program, making it the largest study of its kind.

Source: Yale

A Yale-led analysis of the genomes of more than 1 million people has shed light on the underlying biology of cannabis use disorder and its links to psychiatric disorders, abuse of other substances such as tobacco, and possibly even an elevated risk of developing lung cancer.

For the study, researchers examined a genome-wide set of genetic variants in individuals from multiple ancestry groups enrolled in the U.S. Department of Veterans Affairs’ Million Veteran Program, one of the world’s largest genetic databases, and incorporated additional information from several other genomic databases.

They were able to identify dozens of genetic variants linked to cannabis use disorder and a variety of behavioral and health issues associated with cannabis use disorder.

The study, led by Daniel Levey, assistant professor of psychiatry, and Joel Gelernter, the Foundations Fund Professor of Psychiatry and professor of genetics and of neuroscience, was published Nov. 20 in the journal Nature Genetics.

“Once we understand the biology of cannabis use disorder, we can better understand associated disorders and inform the public of risks associated with marijuana use,” said Levey, lead author of the study.

Marijuana is the most commonly used federally illegal drug in the United States, with more than 48 million people (18% of Americans) using it at least once in 2019, according to the U.S. Centers for Disease Control and Prevention. Previous research has shown that roughly one-third of people who use marijuana develop cannabis use disorder, which is defined as a problematic pattern of cannabis use leading to clinically significant impairment or distress.

The new findings offer insights into the genetic factors that underlie this phenomenon, and other potentially related health risks.

For instance, they found that variants of genes that encode for three different types of receptors on neurons were associated with elevated risk for developing cannabis use disorder.

And they found that these variants linked to cannabis use disorder were also associated with the development of lung cancer. The authors added, however, that more work needs to be done to separate the effects tobacco use and other environmental factors have on cancer diagnoses from those of marijuana use.

“This is the largest genome-wide study of cannabis use disorder ever conducted and as more states legalize or decriminalize the use of marijuana, such studies can help us to understand the public health risks that accompany its increased use,” Gelernter said.

About this genetics and addiction research news

Author: Bess Connolly
Source: Yale
Contact: Bess Connolly – Yale
Image: The image is credited to Neuroscience News

Original Research: Open access.
Multi-ancestry genome-wide association study of cannabis use disorder yields insight into disease biology and public health implications” by Daniel Levey et al. Nature Genetics


Multi-ancestry genome-wide association study of cannabis use disorder yields insight into disease biology and public health implications

As recreational use of cannabis is being decriminalized in many places and medical use widely sanctioned, there are growing concerns about increases in cannabis use disorder (CanUD), which is associated with numerous medical comorbidities.

Here we performed a genome-wide association study of CanUD in the Million Veteran Program (MVP), followed by meta-analysis in 1,054,365 individuals (ncases = 64,314) from four broad ancestries designated by the reference panel used for assignment (European n = 886,025, African n = 123,208, admixed American n = 38,289 and East Asian n = 6,843). Population-specific methods were applied to calculate single nucleotide polymorphism-based heritability within each ancestry.

Statistically significant single nucleotide polymorphism-based heritability for CanUD was observed in all but the smallest population (East Asian). We discovered genome-wide significant loci unique to each ancestry: 22 in European, 2 each in African and East Asian, and 1 in admixed American ancestries.

A genetically informed causal relationship analysis indicated a possible effect of genetic liability for CanUD on lung cancer risk, suggesting potential unanticipated future medical and psychiatric public health consequences that require further study to disentangle from other known risk factors such as cigarette smoking.

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  1. Do not believe this propaganda. These research studies are always skewed and biased towards who ever paid for them. We only get told what they want us to know not the actual truth.

  2. I use my for my chronic pain in my legs from permanent nerve damage. I’ve had 3 back surgeries and am fused from L2-L5. I mix mj and tobacco

  3. This “disorder”, is it comparable to the beer drinking disorder? I’m asking for a friend with a disorder”.

  4. I have all but completely cured an inhairited sczhoprenia with the use of cannibis. Likewise, clinical depression Cannibis use disorder is one of the most ridiculous wastes of taxpayer-funded B.S. I have seen. Just more anti-marijuana drug war propaganda. I have serious questions about the validity of this study. I will not waste my time finding out which anti-marijuana organization funded this horse crap study. It is not worth a waste of my time.

  5. That’s funny, where I live we have medical cannabis and it’s used to treat several mental disorders (especially PTSD in veterans) as well as one of the most successful ways to treat opioid addiction.

    This reads like a study saying that people with depression are found to use more antidepressants.

  6. I have D.I.D(dissassociative identity disorder)- what used to be called Multiple Personality Disorder; severe bi-polar disorder, VERY severe PTSD and severe depression along with bouts of insomnia and periods of not being able to wake up for a couple of days sometimes. Doctors have used me as a Guinea pig trying to find a medicine that works for me to no avail. My entire life the only thing that has ever helped me is smoking Marijuana. If not for that miracle plant I doubt I would still be alive today.

  7. This article is filled with scare tactics. Of course people that smoke cigarettes are more likely to have cancer and people that smoke in general are likely to have lung issues but there’s also other forms of processed cannabis that have great medicinal value without those negative effects on your lungs. It’s not a cure all but it certainly has a wide variety of benefits. From helping you be more considerate and kind to others when the world is full of garbage to helping cancer patients eat regularly and people with Parkinson’s with their tremors to helping folks with seizures. Stop spreading fear and spread positive knowledge and education about moderate use of medicine.

  8. My adopted son (with reactive attachment disorder) has been diagnosed with cannabis induced psychosis (he had two full psychotic breaks) and subsequent schizoaffective disorder.
    I would LOVE to have his genome mapped, as he was an abandoned infant in Haiti. I have zero information about his relatives.

  9. Probably big pharma influence on the study. They don’t want the public knowing how much it can help. There isn’t enough studies being done as it’s still federally illegal. Let’s do more studies before we start with the nonsense. What about edibles??? They don’t cause lung cancer.

  10. I find this quite funny! Some people find something that helps, something other than pharma drugs, and it’s called a disorder! The pharma pill takers are the people with disorder!

  11. I use cannabis.I don’t smoke cigarettes and my gateway has been locked for years.I don’t use harmful substances.My mother is 68 and uses cannabis to treat her bipolar disorder.Its the best remedy to date. She has been struggling with mental illness for most of her life. Doctors have put her on multiple medicines. That marijuana seems to be the only thing that helps.

    1. I am a user which aids in the ability to properly control my emotions/behavior. Not to mention keeps me from abusing alcohol amongst other substances! AIDS in making sure I have an appetite that’s a small few benefits of cannabis use also have friends with turrets which this has aided in. I could go on and on in regards to the benefits more research should def be done

    2. Hi Shawna, I’m CJ. I am a Disabled Veteran with Service Connected Bipolar. Cannabis has helped me significantly since I was diagnosed. Smoking is not the only way to ingest the perscription, you may also ingest THC by consuming edibles. I think the studies need to confirm whether or not this is DNA Demethylation is due to individuals smoking cannabis or ingesting cannabis in general. DNA methylation is neither good nor bad, it’s just something that occurs over time as you consume cannabis.

    3. As a cannabis RN, I agree that plant medicine can be incredibly effective for many people. Not to mention, it produces less side effects than many medications.

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