Addiction Research

Exploring Genetics of Addiction May One Day Lead to Cure

You are made of about 100 trillion cells. The sheer magnitude of this number is striking, representing each of the individual components that make up all of your organs, the majority of them specialized to a particular role and working in tandem with the rest of your body to keep you functioning. Every single one of these cells also contains a copy of your genetic instructions, which are like a basic blueprint for creating you. The tiny variations in the master code—brought about through fresh mutation or an old one inherited from your parents—are what make each of us unique. However, just as these mutations can be fortuitous, they are also known to contribute to a wide range of medical and psychological conditions, and addiction is just one of them.

Scientists have been working to unravel the mystery from a biological, social and psychological perspective, and advancement in this area could lead to new treatments for addiction or even a cure.

Addiction and Your Genes

Genes code for everything. Different combinations of the bases guanine, cytosine, thymine and adenine tell your body which proteins to build, which in turn affects the structure of our bodies. People have so many differences because the random mutations, accidental additions or unintended deletions from this code can produce profound changes in the structure of organs and the traits that follow on from them. Addiction is a brain disease, and like everything else, the structure of your brain is largely determined by your genes.

Drugs have an impact on the human brain because they look like natural neurotransmitters in terms of their higher-order shape. This means that your brain responds to a drug just like it would natural neurotransmitters, which are designed to send messages to other regions or stimulate feelings.

Drugs often work on dopamine, which is the reward chemical of the brain, either by activating the same receptors or alternatively, by stimulating its production in another way (behavioral addictions like gambling also stimulate dopamine release). The receptors for these chemicals are like a lock, with only some specific neurotransmitters (working like “keys”) being able to fit into the space and activate them.

Because your genes ultimately control the shape of these locks, and the code has a degree of individual variation, from a biological perspective it’s possible for some people to be more susceptible to the effects of drugs than others. Scientists theorize that it is likely caused by the interplay between multiple genes, not just a single genetic “on-off” switch.

The Importance of Nurture

If genetics were the only factor in addiction susceptibility, pairs of identical twins would be clearly observed to either be both prone to addiction or not. These things need to be “turned on” in order to take effect. For example, somebody could have a brain hard-wired for nicotine addiction, but if that person never consumed the substance, he wouldn’t gain that initial dopamine boost that forges a memory of the experience as one to repeat, and therefore he would never become addicted.

Similarly, if somebody has a parent who almost died from heroin addiction, although he or she may possess the genetic propensity, the experience could put him or her off ever trying the drug and would therefore mean addiction wouldn’t occur. In short: nurture is important too.

Addiction as a Bio-Psychosocial Phenomenon

This is why addiction is often framed as a bio-psychosocial issue. This definition incorporates the genetic influence, but also accounts for the “nurture” elements, the psychological and social factors that influence addiction susceptibility. For example, somebody with no genetic susceptibility for addiction could still become an alcoholic if he struggled with depression and had friends with an unhealthy relationship with drinking. Genes may form the blueprint for who you are, but your experiences (particularly ones early in life) also have the power to shape the brain and impact who you will become.

Unraveling the Mystery and the Treatment of the Future

Although it’s evident that more than just genetics have an influence on your likelihood of developing an addiction, there is still much to be gained from understanding the underlying physical influencers. Advancement in the area has led to the idea that there may be collections of genes that contribute to susceptibility to addiction to one type of drug in particular.

In the future it may be possible, after a genetic screening, to identify whether you’re at risk of stimulant (such as cocaine) addiction later in life. Similarities have also been uncovered between alcoholism, anxiety and depression, and it could be that genes responsible for drug addiction also have an impact on general mental health. These are a few of the many reasons scientists are working hard to uncover the links between genes and addiction: if we understood the links, it would open the door to new treatments and effective prevention of addiction and psychological illness.

Ultimately, an understanding of the genetics of addiction could lead to an outright cure. If the genetic susceptibility to stimulants turned out to be related to the action of a specific enzyme, for example, a medicine could be tailored to rectify the issue with the enzyme and therefore help to fight or even cure addiction. This may be a long way in the future, but at the very least a more thorough understanding would help to remove the stigma associated with addiction.

The more we understand the genetic and psychosocial influencers in addiction, the less those dependent on drugs will be morally stigmatized for what is seen as a “choice.” Addiction is a brain disease, and gathering evidence in favor of that conclusion makes it abundantly clear that it isn’t a moral failing.