Do Genetics Cause Drug and Alcohol Addiction?

World War II, the deadliest military conflict in history, claimed the lives of over 50 million people.

That death tally accounted for 2.5% of the world’s population. The death tally for alcohol in 2004? 3.2% 

And every year drug abuse causes around 40 million Americans to seriously injure themselves or develop a severe illness. That’s close to 110,000 people a day—5,000 an hour.

Drug abuse leads to homelessness, crime, major social problems and child abuse. 

Drug and alcohol abuse blankets our society affecting nearly every community and family in some way. 

But over the last few decades millions—actually, probably hundreds of millions of studies, papers and awareness drives have prodded the public to take this issue more seriously. Nixon declared a war on drugs. And our nation watches daily as celebrities, politicians, and our friends and relatives continue to suffer the consequences of addiction.

So what’s the disconnect between education, desire and reality? Will the war against drugs ever end?

Studies argue that it won’t–perhaps not until we have a sober generation or two. 

Nuture vs. Nature: If My Parents Were Addicts, Will I Be One? 

Researchers, including Kenneth S. Kendler, M.D., from Virginia Commonwealth University set out to discover the relationship between genetic factors, the environment and the development of drug abuse. (Medical News Today

Often referred to as nature vs. nurture, the team wanted to understand whether children were a product of their genetic background, their environment, or a combination of the two. 

Genes and Addiction

The study isolated 18,115 children born in Sweden but adopted into an American home. Background checks on the adoptees biological parents showed that 8.6% had at least one biological parent with a drug problem.

Forty-five years later, over 50% of this small percentage currently had a drug problem. Researchers concluded that “risk for drug addiction in adopted children is increased by a history in biological parents and siblings.”

The Environment and Addiction 

According to studies accomplished by the National institute on Drug Abuse (NIDA), as much as half of an individual’s risk of becoming addicted to nicotine, alcohol, or other drugs depends on his or her genes/ family background. 

This still leaves half of those addicted to drugs or alcohol in America unaccounted for. The environment seems to be to blame for the cause of their addiction.

However NIDA goes on to say the environment can actually impact your genetic expression: “Environmental influences, such as exposure to drugs or stress, can alter both gene expression and gene function.”


Understanding that genetics plays a role in addiction should cause those with difficult backgrounds to be more careful in experimenting with addictive substances and it should make us think twice about the legacy we are leaving for children.  

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