GENETICS OF ADDICTION
Scientists have identified multiple genes that likely contribute to the development of drug addiction and alcoholism. It has become apparent that there is no single gene that causes drug and alcohol addiction. Rather, the genetics of addiction is extremely complex, with multiple genes influencing the action of each other.
It is a combination of the expression of various genes and their relationship to the environment that influences the presence or absence of substance abuse. So, just because a person has genes that contribute to addiction, it doesn’t mean they will become addicted, and vice versa. There are also genes that likely protect one from becoming a drug addict or alcoholic.
The environment that one is exposed to is probably more important for the first use of alcohol or drugs and the pattern that develops prior to the onset of drug addiction and alcoholism. One’s genetic makeup, however, is most strongly tied to the progression from substance use to substance abuse and ultimately onwards to chemical dependence. In those individuals who possess genes that can elicit the formation of addiction, repeated drug and alcohol use results in long-lasting neurobiological changes that stimulate further reward-seeking behavior through continued and increasing use. These changes are involved in tolerance, craving and withdrawal, which prompts drug-seeking behavior and increases impulsivity. The result is that the addict or alcoholic ultimately enters a state of uncontrolled use.
Large families with patterns of drug addiction and alcoholism have been studied to determine which genes are present or absent in those affected and those who are not affected. A particularly important methodology for the identification of genes is the study of twins, both those raised together and separately. In any case, it has been stated that one’s genetic background likely contributes a little over 50% of the risk of developing addiction, the rest is contributed by the environment, and psychological and social factors.
The genetics of addiction is important for two distinct reasons. The first is that any gene that is identified to be related to addiction is a potential target for medications. For example, a medication that can alter the function of a certain neuroreceptor or the substance that binds to the receptor, or that can block or activate an enzyme could potentially become a treatment for addiction. Also, genetic testing is currently being used to determine how the patient metabolizes various medications, which allows the physician to prescribe the most appropriate medication for the patient.
With continued technological advancements and more focus given to the study of drug addiction and alcoholism and its treatment, it is likely that more effective medical treatments for addiction are on the horizon. Regardless of one’s genetic background, with an appropriate environment and early prevention, the progression of drug and alcohol abuse to addiction can be halted. Once addiction takes hold, prompt and intensive treatment at a drug and alcohol rehab can significantly increase the ability of one to enter recovery and live a fulfilling life, sparing the addict and alcoholic from the consequences of a lifelong pattern of substance use.