Not every person is born the same way or with the same genetic make up. This is what gives each person different skin tones, eye color, temperaments, tastes, etc. These differences in genetics also apply to drug use and addiction, including the propensity or susceptibility a person has to want to use drugs or become addicted. Because genetics are the “functional units that make up our DNA [and] provide the information that directs our bodies’ basic cellular activities,” many scientists study genetics as it relates to addiction hoping to pinpoint the areas that may cause a person to become addicted to a particular drug and to develop a cure for addiction by targeting the gene that causes the problem in the first place.
For example, from the research we have done on the internet, we have come to notice one of the basic patterns that comes with addiction and the brain - chemically speaking, drugs and drug addiction largely revolve around sparking one culprit: dopamine. This does not mean that there aren’t other chemicals that react with drugs. There are, and lots of them (for example, serotonin). However, especially as addiction relates to genetics, we have noticed several studies that continually connect a person’s propensity to heavily use drugs or be more likely to become addicted with variations of genes that react with dopamine in particular and not normal ways.
Dopamine is a major focus of study when it comes to addiction because it is one of the main chemicals ignited by drugs. This is because, in many cases, dopamine is the chemical that is released and stimulates the reward center of the brain. This is the area that gives a person pleasure. So, several drugs have been developed to artificially signal the release of dopamine, which gives people pleasure when they take drugs.
This post will look at some the studies about dopamine as it relates to genetics and addiction. Then, we will go into broader connections about why genetics are a second reason for why a person becomes addicted to drugs and alcohol.
A study led by Vanderbilt University neuroscience PhD candidate, Joshua Buckholtz, proposed that people who are more impulsive might have less active dopamine receptors. Dopamine receptors are in the central nervous system and send and receive dopamine, which is the chemical that facilitates motivation, pleasure, cognition, memory, learning, and fine motor control. So, Buckholtz’s study suggests that people that are impulsive are not getting as steady a stream of dopamine to feed their happiness and pleasure levels in their brains. The study also proposed that when stimulated, these people would get a huge burst of dopamine (causing the impulsive, gotta have it now, sensation). This was proven to be true by scanning brains of people when they were given an amphetamine. Then after asking if they wanted more amphetamine, the people with higher impulsive tendencies (and less active dopamine receptors) had “subjectively strong cravings”. As the study concludes, this may have a connection with substance abuse because, since when people with less productive dopamine receptors are stimulated by something like a drug, they want it more than others who have a steady stream of s=dopamine.
Scientists found that when people had the gene for the dopamine receptor, DRD4, were more likely to drink twice as much as other people who drank 3 or more drinks. Therefore, if you have this specific gene, you may be more susceptible to drinking more alcohol, which could lead to addiction.
A 2001 study done by researchers in France found that there was no significant difference in the DRD3 gene polymorphism between controls and alcoholic patience in their study, regardless of sensation seeking score, addictive or psychiatric comobidity, alcoholism typology, and clinical specificities of alcoholism.
Compared to the Study #2, Study #3 shows why genetics only plays a partial role in addiction – because there are many mutations, each having their own specific properties, the science of using genetics to determine whether someone is going to become an addict, simply based on their genetics, is not far enough along to make such conclusions.
It is clear that there are links between genetics and addiction. However, the science behind determining what genes a person has and whether or not specific genes mean he/she will become an addict is still too far to make any sweeping generalizations, predictions, or to even create a treatment based on these findings.