When a person takes their first drink, or makes the decision to use drugs for the first time, they are influenced by social, societal, familial and biological inputs. But once the alcohol or drug enters the person’s system, their risk of becoming addicted varies considerably. Even among seemingly like individuals – brothers and sisters, people from a region, or those of French heritage, for example – susceptibility to addiction can vary from individual to individual. Why?
Your genetic make up has much to do with it.
Research shows that genes are responsible for about half the risk for alcoholism and drug addiction. While genetics are not the sole determinant, their presence in one’s body may increase the likelihood that he or she will become dependent on alcohol or drugs if consumed.
Your health is the constant interaction between your genes and your environment. We know that certain people are genetically pre-disposed to high blood pressure, for example while all of us can increase our risk environmentally with a poor diet, stress, and lack of exercise.
Some diseases, like sickle cell anemia or cystic fibrosis, are caused by an error in a single gene. Most diseases, though, like alcoholism and drug dependence, are considered genetically complex and involve variations in a number of different genes. 
What Does Research Say?
Many scientific studies show that drug and alcohol dependence runs in families. Research conducted on twins and adopted children has shown the impact of genetics in relation to alcohol and drug dependence.
“Sons of alcoholic fathers are up to nine times as likely to develop drinking problems as the general population,” says Akikur Mohamad, MD, a nationally recognized addiction expert. “Babies of alcoholics adopted into non-drinking homes have almost the same odds of alcoholism as they would if they’d stayed with their birth parents.”
We are all genetically predisposed to some levels of addictive behavior. Eating nutritious food vice unhealthy food releases a positive reaction in the body that signals our brain to seek more of this substance in the future. We are born with this innate predisposition. 
But while all of us have the potential for addiction, some are more genetically predisposed to addiction than others. From the first drink of alcohol, some will drink “alcoholically” from that very moment because of their genetic makeup. Many others who drink socially will never develop a dependence on alcohol, while others who drink moderately over time may become alcoholics more from them “reprogramming their brain” than from an inherent genetic predisposition to dependency to alcohol.
Reprogramming Of Our Brain
Just because we are not born genetically predisposed to addiction, does not mean we are in the clear. There are many alcoholics and drug addicts who have created that situation through their behavior, effectively reprogramming their brain and system to become dependent on drugs or alcohol.
Many stimulants dramatically elevate a response that releases much higher-than-normal levels of dopamine into your system, triggering pleasure sensors. Over time, your body inhibits its natural production of dopamine because of the influx from drug-induced stimulation. Your body has effectively become conditioned to the drug producing pleasure. You have reprogrammed you system to feel as though it needs the drug to live. Each successive use of the drug reinforces that need, driving the user deeper and deeper into their dependency.
Ultimately, We Control Our Likelihood of Addiction
Not everyone born to an alcoholic or a drug addict is destined to be an addict themselves. And even if one is born predisposed to addiction based on their genetic makeup, they always have the ability to make environmental choices that do not involve the consumption of alcohol or drugs. Being born with a dependent genetic makeup, as well as being raised in an addictive or abusive household, is not a life sentence of pain and suffering. Creating a healthy environment, rooted in daily good choices, can ensure a lifetime of balance, health and happiness.