Is Addiction an Inherited Illness?

Many clients who attend our alcohol rehab centre claim to hail from a ‘long line of heavy drinkers’. Some scientist claim ‘addictive tendencies’ pass down from generation by virtue of certain genetic characteristics. In this post, we outline some of the studies conducted in this important area over the last five years.

However, one thing is clear from the genetic studies of addiction: there does not exist an ‘addiction gene’. As explained below, there exists many factors which determine whether or not a person will become addicted. Many of these factors are genetic, whilst some are not. Furthermore, many people who exhibit genetics making them more likely to become addicted do in fact live healthy, addiction-free lives.

2010 study conducted by the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory

This study examined the brain of mice who have been exposed to alcohol over a long period of time.

Some of the mice lacked a brain receptor known as ‘dopamine D2’. This receptor responds to dopamine. Dopamine is the brain’s so-called ‘feel good’ hormone. Mice who lacked D2 receptors and exposed to alcohol suffered exaggerated biochemical changes in the brain synonymous with addiction.

The study thus concludes expose to alcohol is more likely to lead to alcoholism for those who lack D2 dopamine receptors in the brain compared to those who do not lack this receptor.

Head researcher, Peter Thanos, said: “This study shows that the effects of chronic alcohol consumption on brain chemistry are critically influenced by an individual’s pre-existing genetic makeup.”

Scientists reason a lack of D2 receptors in the brain mean these people struggle to experience normal emotions of pleasure. This means many of these people turn to substance misuse or certain behaviours such as over-eating, gambling or gaming in order to make up for this shortfall in natural pleasure.

2012 study conducted at the University of Cambridge

The genetic therapy of addiction suggests addictive behaviours are ‘hard-wired’ into users. Back in 2012, scientists at the University of Cambridge claim these addicts suffer from genetic features that alter chemicals located within the brain. Scientists consider these features as ‘abnormalities’. These ‘abnormalities’ were discovered by subjecting addicts to brain scans.

People with this brain abnormality struggled to exercise self-control over their behaviour. This in turn lead to substance misuse or behavioural addiction.

The 2012 study involved scanning the brain of fifty cocaine addicts and that of their siblings. A control group of non-addicts with no addicted sibling also received a brain scan.

Shockingly the study revealed drug addicts AND their siblings both suffered from an abnormality in the frontostriatal region of the brain. The frontostriatal region is responsible for self-control. Thus, the abnormality hinders addicts’ ability to exercise self-control over their using behaviours.

Head research, Dr Karen Ersche, said: “Our findings now shed light on why the risk of becoming addicted to drugs is increased in people with a family history of drug or alcohol dependence: parts of their brains underlying self-control abilities work less efficiently.”

2014 study conducted at Texas University

During 2014, scientists at Texas University claim to have discovered the ‘genes’ they believe causes addictive behaviours.

These scientist claim ‘addictive DNA’ is only found in people who suffer from addiction.

This study compared genetic code contained in brain tissue of non-alcoholics to that of tissue belonging to people suffering from alcoholism. The results revealed brain tissue belonging to alcoholics contained linked networks of genes not present for those who did not suffer from alcoholism.

Head researcher, R. Ardron Harris, said: “This provides the most comprehensive picture to date of the gene sets that drive alcohol dependence. We now have a much clearer picture of where specific traits related to alcohol dependence overlap with specific expressions in genetic code”

This study was the first in its kind because it used bioinformatics technology of RNA sequencing in highlighting the link between genetic groupings and the occurrence of alcoholism.

Implications of these studies

Clearly genetic trails are a major contributory factor for the occurrence of addiction.

These studies highlight the link between genetics and addiction. We suggest policymakers could give educational institutions power to identify children or teens at risk of developing addiction and provide additional education on the subject.

Scientists may also one day be able to genetic develop screening technology to identify who is and who is not vulnerable to addiction. This technology would significantly aid our ability to prevent addiction before it is given time to develop.