Anyone who has learned about drugs knows they can be extremely addictive. Some might wonder if having a family history of drug dependence will make it easier for them to become addicted. Karen D. Ersche and others did a study called “Abnormal Brain Structure Implicated in Stimulant Drug Addiction” to find out.
The study contained fifty sibling pairs, that had family history of drug dependence, where one sibling was dependent on drugs and the other had never been dependent on drugs. The siblings were compared with each other and with fifty volunteers who had no family history of drug dependence and were not dependent on drugs. There were two tests used to compare the siblings and the volunteers.
The first test was Stop-Signal Task; this test measures the “stop signal reaction time” or SSRT. This is done by showing the person a series of pictures and having the person react a certain way to the pictures. This creates a repetitive response that the person has to suppress when a random auditory signal is given. The time it takes for the person to stop what they were doing is the SSRT. Having a lower SSRT means it did not take long for the person to stop what they were doing and is considered a good result. The test can be used to test a person’s overall self-control. Having a shorter or lower SSRT means having more self-control than a person who has a longer or higher SSRT.
The SSRT’s did not vary much between the siblings, who had a slower SSRT than the unrelated volunteers. This suggests that the siblings have less self-control than the volunteers. Since one of the siblings is not dependent on drugs it shows that the area of the brain that controls response time and self-control is a familial trait and can be inherited. This is not surprising because brain structure is partly inherited.
The second test that was used is called “fractional anisotropy” or FA. This is a scan of the brain and measures the “general index of integrity of white matter fiber tracts”. To translate, in the brain, white matter is where signals are transferred. The person is given a score between 0 and 1. A higher FA means that the diffusion rate in the white matter is in one direction, which is what is desired because having only one direction for the signal to travel gives a quicker response. With a lower FA the diffusion rate is going in many directions and is not as effective because the signal is not moving in the desired one direction.
After finding the SSRT and the FA, for the siblings and the volunteers, the scores were compared to find out if there was a correlation between them. Ershe and others were trying to prove that having a slower SSRT means having a smaller FA. The correlation is a number between -1 to 1 and determines how strongly related two items are to each other. A correlation of 1 or -1 means a strong correlation and 0 means no correlation. The correlation between SSRT and FA is a disappointing 0.24 and shows that there is only a small correlation between SSRT and FA and is not strongly support Ershe and others theory. Without strong support, having a slower SSRT does not mean having a smaller FA. This leads to many possibilities and shows that having a family history is not a big factor when it comes to becoming dependent on drugs.
In reality, family history is only a small factor when it comes to drug dependence. This is obvious because the study contains fifty siblings who are not dependent on drugs. The conclusion of the study tries to explain this by saying that the siblings contain “resilience factors that counteract the familial vulnerability to drug dependence”. What the study does not consider is the many other factors that go into a person using drugs other than the brain.
What the study showed unintentionally is that even people with a family history can resist the allure of drugs and avoid becoming dependent on them. This illustrates that there is more to drug dependency than just science. The study does support the idea of mostly inherited brain structure, but does not go into detail if there is a difference between the brain structures in the siblings. The study mainly focuses on the scientific aspect of the brain, but the brain cannot be as easily understood like the other organs in the body. Brain structure can be inherited, but the structure of the brain is also affected by the unique social experiences of each individual. Therefore, to understand why one of the siblings is not dependent on drugs, one must look at that sibling’s social environment.
Everybody knows that there are a lot of social reasons that goes into every decision. Finding out what the siblings do and finding out the reason one of the siblings started doing drugs is important information that cannot be found in the brain structure.
By only looking at the scientific aspect of drug dependency and ignoring the social aspects demonstrates that people are looking for a way to take responsibility away from the individual and the society that should be taking care of them. If a person is predisposed to being dependent on drugs then there is no reason to try and help them because they will become dependent on drugs no matter what is done for them. It is easy to see that there does not need to be family history of dependency on drugs for a person to become dependent on drugs. This shows that there are social reasons for people to become dependent.
To become dependent on drugs, the person has to keep going back and taking the drugs. Genetically, having a family history will not push a person to keep doing drugs. The main culprit is social interaction and environment. For example, if a person has a friend who takes drugs, the person may decide to take drugs themselves because his or her friend is doing it. There are also many other reasons that a person would want to keep taking drugs like curiosity, pleasure, help with focusing, rebellion, boredom, to fit-in with a group, etc. The only thing that the family history contributes is getting the person dependent more easily and overall that is only a small factor and does not deserve all the credit.
One of the main things the study lacks is the social aspect of taking drugs. Knowing the social environment of each sibling would make it easier to understand why one sibling is dependent on drugs and the other is not. There is also the fact that a person does not need to have a family history of drug dependence to become dependent themselves. This is an extremely important point that demonstrates that drug dependence is not only associated with certain brain abnormalities.
It is important to remember that this study is mainly based on science. It supports the idea that brain structure is mostly inherited through family but it cannot provide a strong case for drug dependence being a familial trait. It also does not provide a solid explanation as to why the non-drug dependent sibling is not dependent on drugs. Since the study is mainly based on science the social factors could not be further explored. The study does show, though unintentionally, that social factors are extremely important when it comes to drug dependency. Concentrating on just the science side of the brain and familial traits closes off exploring other variables, such as social explanations, that are just as valid at explaining drug dependency as the scientific explanations.