There is mixed evidence as to whether drug addiction is actually predisposed by the genes or not but one thing that is known for sure is that addictive behavior is predisposed. What this means is that although actually being addicted to drugs may not be genetic there are genetic factors that play a role in whether or not a person has what is known as an “addictive personality.”
Why can some people use drugs casually and not become addicted but others use just a few times and the addiction sets in? How much of drug addiction can be imposed on a predisposition that is the result of genetics? Why does addiction strike one person so much differently than it does the next?
Drug Addiction and Genetics
There is evidence that shows as much as 50% of a person’s likelihood to become addicted to a drug is genetically predisposed. What this means is that the genes play a key role in drug addiction but they do not play the only role in determining whether or not a person will become addicted to drugs as a result of recreational or casual drug abuse.
There are thousands of genes that determine everything about an individual from skin, hair and eye color to personality and cognitive ability. Of the 40,000 genes that are expressed in the part of the brain where drugs show their most profound effects many may or may not be directly linked to drug addiction. Geneticists have been researching the similarities and differences between family members who are addicts in hopes of determining those genes which are directly responsible for determining whether or not an individual will become addicted to drugs.
While evidence does suggest that heredity and genetics do play a role in increasing the likelihood of an individual becoming addicted to drugs there are many other factors that come into play as well. While addiction does tend to run in families it is still unclear how much of the disease of addiction is transmitted genetically and how much of the disease is the result of learning addictive behaviors from family or society.
Genetic Predisposition Studies
While there have been many different studies conducted to determine how much genetics do determine drug addiction some of the most profound include studies on twins and studies that have been conducted on adopted children. One study compared the alcoholism rates of both individuals who had been adopted but were born to alcoholic parents and those who were born to non alcoholic parents. Statistics show that those who were born to alcoholic parents, although they never knew their parents and were not raised in alcoholic households were as much as 3 times more likely to become addicted to alcohol themselves.
Another study on the genetic predisposition of drug addiction focused on twins. One study found that identical twins (those who share the same genetic makeup) are up to 200% more likely to suffer from alcoholism than fraternal (not identical) twins. Similar statistics have been found for other types of drug abuse amongst twins including cocaine, stimulants and sedatives.