Compulsive Behaviors of College Students Cause Long Term Effects Related to Brain Damage and Risk of Addiction

Here's an infographic I made to
highlight the "take home" message
in this article.

The most extreme example of typical college student can be imagined as a mediocre student that spends most of their time drinking heavily, abusing other substances, and pulling the occasional all-nighter to complete all the schoolwork they've been putting off for months. However, the effects of behaviors like heavy drinking when performed by adolescents don't all go away as quickly as the hangover does. Many of these behaviors can cause irreversible changes in the genes that have long term effects that last long into adulthood. Compulsive, radical behaviors like binge drinking and smoking cause changes in the genes that lead increased risk for addiction, increased stress levels, increased risk of heart disease, and damaged brain cells. All of these effects become permanently embedded in the genes if the behaviors do not stop before late adulthood. 



Active genes are responsible for a function in the body, but active genes can become inactive.

Our genes each contain the information to make a specific protein. Proteins carry out the functions in our cells and in our bodies. Your eye color, the way your voice sounds, and the way your metabolism works each have a protein and a gene that is responsible for each of those. Scientists call this process Gene Expression. An active gene is a gene that is being expressed, meaning it is making a protein, and responsible for some functional process in your body. An inactive gene is not expressed; it will not make the protein that it is supposed to. An inactive gene is not always a bad thing though; the ability to inactivate genes allows us to have different cell types (skin cells, blood cells) for example. In the video to the right, Researcher and Professor of Genetics at the University of Maryland, Dr. David Straney, explains why we need some genes to be inactivated, or turned off. To learn more about genes, how and why they need to be activated or inactivated, try this interactive teaching module provided by the Genetic Science Learning Center at the University of Utah.

Genes can be activated or inactived by chemicals in our bodies that respond to a signal from the environment. 

Nature 441, 143-145 (11 May 2006) | doi:10.1038/441143a 

Since genes can be readily activated or inactivated, there must be a way for the body to turn on or off certain genes in response to different signals. It turns out, small chemical groups called methyl groups and acetyl groups can be added to certain places on the genes to activate or inactivate them. Scientists call this phenomenon Epigenetics. This video, also from the Genetic Science Learning Center, includes an excellent visualization and explanation of how this process works. Epigenetic changes can become permanent if they are not reversed within a certain time period. After a certain point, you cannot remove the groups that inactivate certain genes. Epigenetic changes are signaled by environmental cues or behaviors. These changes can be positive or negative. Dr. Straney explained one example of baby mice that experience more nurturing from their mother within the first week of life will have genes that act as the body's natural stress reducer activated, and those mice will grow up to be less scared and less anxious throughout adulthood. These genes cannot be influenced after the first week of life, so these changes are irreversible. If you want to see how that works, click here for an interactive module that lets you determine how much the pup is nurtured and how that effects the genes. On the other hand, behaviors like binge drinking or cigarette smoking can inactivate necessary genes, or even activate the wrong ones.


Binge drinking increases risk for Alcohol Addiction, Heart Disease, and Kills Brain Cells. 

An Infographic that represents the
amount of alcohol that college
students use. 8.5 million students
or 50 % of all college students
binge drink, and are can are
most likely affected by these gene
changes.

The effects of Binge Drinking may come as no surprise to us, but knowing exactly how this behavior manipulates a healthy body may convince binge drinkers to finally change their ways. In one study, alcohol abuse in adolescents was proven to cause irreversible changes in the genes that control parts of the heart called the cardiomyopathy signaling pathway. These changes increase susceptibility to heart disease which persists throughout the lifetime since the changes are irreversible. In another study, regular binge-drinking episodes were proven to increase the likelihood of alcohol addiction later by two different mechanisms. Binge drinking causes an increase in the activity of the genes in the part of the brain that controls addiction. Binge drinking also causes a decrease in the activity of the genes in the part of the brain that serves as the body's natural reward system. Deactivating the body's natural reward system causes addiction because alcohol becomes the body's external source of reward as a replacement, and the user needs alcohol to feel rewarded. Both of these strategies increase the likelihood of alcohol addiction throughout the binge-drinker's lifetime. In the same study, binge drinking was also proven to increase the activity of a gene that inhibits neuron survival, which basically means it prevents brain cells from surviving. All of these genetic changes are encoded by our cells and maintained, so the effects are long lasting and persist over the lifetime.

Surprisingly, nicotine usage has no substantial effect on brain development, but the imposed food restriction causes increased stress levels.

Researchers were unable to find any substantial evidence that Nicotine has any effects at all on brain development or brain signaling pathways. Nicotine is the active ingredient in cigarettes, a common substance abused by college students, and it make sense that Nicotine would be the thing that to cause any negative effects on the brain due to cigarette smoking. However, one of the major side effects of Nicotine abuse is a decrease in appetite. In the same study that disproved nicotine to affect the brain, this "induced food restriction" was proven to cause major genetic changes that inhibited the brain's natural stress response pathway, and led to significantly increased stress levels that lasted throughout adulthood.

Finally, succoumbing to these compulsive behaviors amplifies the effect on the genes. The effects are additive, so with every yes, it becomes harder and harder to say no. 

Listen to Dr. Straney's final thoughts on how compulsive behavior can be examined genetically.