Many environmental factors help determine the risk level each individual has to become addicted to smoking. Smokers are often influenced by family members and friends who smoke, making smoking seem like a normal part of life.

However, research has shown that genetic factors are also important in determining a individual’s likelihood of developing different types of addiction, including addictions to drugs, alcohol and tobacco. A recent study led by Dr. Jacqueline M. Vink and Professor Dorret L. Boomsma has further investigated this connection between genes and addiction, specifically addiction to smoking.

The study, published in The American Journal of Human Genetics, made a significant breakthrough by identifying the specific groups of genes active in smoking behavior and addiction vulnerability. The effort was initiated by the Department of Biological Psychology at Vrje Universiteit in Amsterdam and was collaborated by several international research groups.

The researchers used a genome-wide association study to investigate the DNA of smokers and non-smokers for more than 500,000 genetic variants. The variants were tested to see whether certain variants occurred in smokers at a higher or lower level.

The researchers discovered that several groups of genes held variants of interest. In one group of genes, a common variant was found related to glutamate. Glutamate is a neurotransmitter that has a specific role in normal brain processes, but is also associated with addiction vulnerability.

A second group was identified that may also play a significant role with addiction. The NTRK2 gene is located in a chromosomal region that affects addiction vulnerability and the GRB14 gene which may restrict the genes that regulate nicotine receptors and may alter the reward response that a person has after smoking a cigarette.

Some of the genes identified in the study have been identified as playing a role in several types of psychiatric disorders, including schizophrenia, attention deficit hyperactive disorder, autism, and multiple types of addiction. Each of these psychiatric disorders has also been connected with smoking.

Dr. Vink cautions that an identified predisposition for smoking does not imply that a person’s offspring will develop an addiction to nicotine. Though they may have more difficulty with cessation, each smoker should understand that a genetic predisoposition is never an excuse to continue an unhealthy behavior.

As research continues to understand the genetic influence over different types of addiction, there may be connections found between many types of behaviors. It may soon be possible to target individuals tested for “addiction genes’ for additional education and prevention efforts.