Addiction and the Brain
Addiction is a word that is used often. It is hard to get through a day without hearing something about addiction. It might be a news report talking about the large numbers of Americans who are addicted to prescription pain medication. It might he hearing that one of your favorite entertainers has been hospitalized or has died because of a drug overdose. It might be as simple as one of your friends saying that she is addicted to her phone. You would think that a word that is used so often would be more understood. Unfortunately, that is not the case.
In this class, you will learn about the harm that certain substances can cause to your physical and mental health. You will learn, for example, how smoking and vaping damage vital body systems. You will learn how drugs, both legal and illegal, cause harm. You will learn how alcohol use affects the body and mind, and how excessive drinking leads to major disease.
Humans are naturally curious. Humans are risk-takers. These are not bad qualities. In fact, curiosity and risk-taking are how our modern society was built. Every discovery that has ever been made started with curiosity and most likely required taking some risk. Some risks, once they are carefully evaluated, are worth taking to satisfy curiosity. If you want to try a move on a skateboard that you have never attempted before, you might break a bone even if you are wearing proper safety equipment. That is a risk that you can probably evaluate. You might not have ever broken a bone before, but you probably know someone who has. You may decide that the risk is too high, or you might think that it is worth the risk.
The cost of addiction is so high that it is nearly impossible to accurately measure. For reasons that we'll get into later, your brain is simply not capable of properly evaluating the risk of experimenting with an addictive substance. The temptations are certainly there. You see addictive substances all around you. Some of them might be used regularly by trusted adults. It may be hard to understand why it is okay for an adult to have a glass of wine with dinner but not okay for you. Hopefully, you will be able to understand once you have completed this class.
What is Addiction?
Addiction is a long-term disease where an individual has an overwhelming desire to find and use drugs, even though there are dangerous consequences. Addiction is a disease because it can result in long-term changes in the brain structure, function, and behaviors.
It is easy to confuse addiction with a habit. Even though habits might be hard to break, they do not cause changes in the structure or function of the brain. There are some habits that may even cause temporary changes in the way that the brain works, but they simply do not meet the classic definition of addiction. That's why you can't really get addicted to your phone, or to video games, or to eating candy. Those activities may exert a powerful influence on you, but once you are able to break free from them, there is no evidence of permanent changes to your brain. This, by the way, is one of those times that I need to warn you. There is a lot of research being done right now about the effects of phones, social media sites, and video games on teens. It may turn out that some or all of those activities meet the classic definition of addictive. For now, though, they fall outside of that definition.
Addiction is based on the way that the reward pathway in the brain works. Our brain's reward pathway is activated often. Anytime we do something that makes us feel good, it's because our brain told us to feel good. This is caused by a specific brain chemical (a neurotransmitter) called dopamine. It is the release of dopamine that makes us feel good. At the same time, a second neurotransmitter called serotonin helps to keep us in balance. Serotonin basically works to put the brakes on dopamine. Addictive substances cause the brain to release dopamine, often in much higher amounts than would be released for typical activities that make us feel good, and they also depress the release of serotonin. In other words, addictive substances put the accelerator to the floor when it comes to dopamine, and they block serotonin from slowing things down. You can learn more about this is the Khan Academy video linked to below.
Tolerance
One aspect of addiction that is particularly harmful is called tolerance. Tolerance is when you need more and more of a substance to achieve the same effect. For example, beginning drug users do not need very much to achieve the desired effect. As time goes on, though, they need more and more of the drug. When you hear about drug addicts who lose everything they have because they are spending all of their money on drugs, that's because of tolerance. Or perhaps you have a friend who started smoking or vaping. You know that they started doing it just on weekends. Then they started doing it every day before and after school. Now they are ditching class and smoking or vaping in the bathroom. That is because of tolerance. The amount of nicotine that it once took to give them the feeling they desired isn't enough anymore. The biological basis of tolerance is explained well in the Khan Academy video linked to below.
Withdrawal
Once a person is addicted, their brain cannot function normally without the addictive substance. The chemistry and structure of the brain has been changed by the addictive substance, and the only way the addicted person can feel normal is by taking more of the substance. Eventually the brain can be returned to a normal state, but it is not an easy process. Breaking an addiction has many side effects, including anxiety, depression, insomnia, memory loss, headaches, heart palpitations, vomiting, diarrhea, muscle tremors, and sweating.
What Makes Some Substances More Addictive than Other Substances?
How addictive any substance is depends on various factors. One factor involves how quickly the substance can get to the brain. Substances that are smoked or injected tend to reach the brain faster than substances that are ingested. The faster substances reach the brain, the more addictive they tend to be. Another factor is how quickly the effect fades. The faster the effect of a substance fades, the more addictive it is likely to be, because the person needs more of the substance faster. These might be the reasons that nicotine is so addictive. Because it is generally inhaled, nicotine reaches the brain quickly. But, nicotine metabolizes quickly in the body, so a nicotine user needs more nicotine in a short time in order to achieve the desired effect. You can learn more about this in the How Nicotine Works article linked to below.
Addiction and the Adolescent Brain
As bad as addiction is for adults, it's even worse for teens. That's because teens have brains that are structured differently from adults. Simply put, there are parts of the teen brain that are not completely developed. In particular, the prefrontal cortex of the teen brain is not completely developed. The prefrontal cortex is responsible for things like planning. You can see this lack of development all around you. How many times have you known about a project or other assignment that is due but just can't seem to find the time to complete it? How many times have you walked into class knowing exactly what will be going on but have forgotten to bring necessary supplies? I know that adults will often blame these behaviors on a lack of caring or an attitude that you are not "serious" about school. I have done that myself, many times. But really, these behaviors are more likely to be associated with an underdeveloped prefrontal cortex. Try that excuse out on your parents! On second thought, don't.
The way that drugs work on the brain, and the fact that teens have an under developed prefrontal cortex, puts teens at especially high risk for addiction. Scientific research suggests that teens need to consume more of an intoxicating substance than an adult to achieve the same effect. Teens lack the ability to deal effectively with stress (they have less experience dealing with stress than adults do) and may be more likely to use drugs to relieve that stress. Teens may have undiagnosed medical conditions that lead them to self-medicate. Teens are highly susceptible to external influences like advertising and peer pressure. They are often interested in emulating entertainers they admire. And, let's be honest, teens are surrounded by what often seem to be discriminatory rules -- there is a long list of things that are okay for adults but not okay, and even illegal, for teens.
All of these factors work together and make the use of addictive substances by teens more dangerous. The lack of aversion to risk, high degree of sensation-seeking, lack of experience, susceptibility to external factors, and underdeveloped prefrontal cortex increase the chances that teens will be tempted to use addictive substances and, if they do, become addicted to these substances more quickly than adults would. You can learn more about the teen brain in the TED Talks video and the Adolescent Brain Development and Drugs article linked to below.
Additional Resources
There are excellent resources already available that explain addiction better than I can. To do well on the Addiction test, and to get a head start on future tests covering tobacco, alcohol, and drugs, you should carefully review and understand the articles and videos linked to below.
Article - Adolescent Brain Development and Drugs
Video - Khan Academy-Reward Pathway in the Brain
Video - Khan Academy-Tolerance and Withdrawal