Scientists are beginning to understand the genetic differences that help explain different responses people have to substances.
Like how one long-time smoker can easily quit, while another will struggle and stay addicted.
The researchers from the University of North Carolina, led by Hyejung Won, PhD, have been learning more about the genetic differences to give a better chance for creating therapies that can help millions of people with addiction struggles.
One of the reasons for explaining addiction is the individual’s genetic proclivity to abuse substances.
The UNC School of Medicine researchers identified the genes linked to cigarette smoking and drinking.
It was found these genes are over-represented in some kinds of neurons, brain cells which trigger other cells to send signals throughout the brain.
It has been found and published in the journal Molecular Psychiatry, that the genes underlying cigarette smoking are linked to pain perception and response to food, and also the abuse of other drugs, such as cocaine.
Other genes that are associated with alcohol use were linked to stress, learning and the abuse of other drugs such as morphine.
Few treatment options are available for long-term substance use and substance use disorders, in large part because more understanding of the biological processes is needed.
“We know from twin studies that genetics may account for why some people use and abuse substances, aside from environmental factors, such as family issues or personal trauma,” Won said.
“Genetic studies such as genome-wide association studies (GWAS) provide a way to identify genes associated with complex human traits, such as nicotine addiction or drinking heavily.”
Using GWAS, regions in the genome that play roles in particular traits can be identified and compared to individuals who do not exhibit the trait.
Genes linked with alcohol use and cigarette smoking were also associated with other types of substances.
“Our analyses showed that expression of genes shared between cigarette smoking and alcohol use traits can be altered by other types of substances such as cocaine,” Won said.
“By characterizing the biological function of these genes, we will be able to identify the biological mechanisms underlying addiction, which could be generalised to various forms of substance use disorder.”
The findings have made it possible for the UNC researchers and others to investigate the molecules that make addiction much less likely.