How Substance Abuse Affects the Body and Brain

3/8/25

As a teenager in 2025, you’ve likely heard and seen a lot about drugs…maybe you have family and friends who use them, have tried them yourself, or have seen posts all over Tiktok or Instagram. There’s a ton of information out there: most which talk about how substances are harmful. However, there’s not as much that covers what makes them so dangerous- that’s what this article will get into.

First of all, what are drugs? Drugs are chemical substances that are used in many ways. They can be prescribed by a doctor to treat medical-related conditions, but are also used for fun. It can range from anything like alcohol, nicotine (found in cigarettes or vapes), and steroids, to “hard drugs,” like cocaine. Both are toxic, though hard drugs can be even more dangerous.
When taking a drug, it first enters the bloodstream and moves throughout the body. In doing so, it reaches the body’s tissues. They get absorbed into different tissues at different speeds. Some drugs can gather in tissues which release the drug slowly over time. This means the effects can be stronger and last longer.
Most of these substances are changed by the body to make them less toxic. This happens in the liver. Drugs also have an effect on the brain: they affect the part of the brain that makes you feel happy. This produces a surge of dopamine, which is a hormone that produces good feelings.

So, if they appear to be producing these great emotions within the brain, what makes them so dangerous? Well, all this dopamine changes the brain over time. Taking drugs floods the reward pathway: causing the brain to remember this feeling and associate it with the substance. The more you take these drugs, the more the brain gets used to these surges, and the more it wants them. When the cravings become stronger, more drugs need to be taken to achieve this ‘rush’. This is how addiction begins. Note the risk of addiction on it changes depending on the substance. Anyone can become addicted to drugs, regardless of their lives. Addiction can look different for everyone and may affect people in various ways.
Addiction can make life very difficult. Drugs only make it harder to manage school, sports, work, and social activities. It impacts physical and mental health: affecting sleep, behavior, and emotions. Imagine how much more stressful it would be to deal with these symptoms and side effects and daily life. Also, it can cost a lot of money, time, and effort to get a hold of substances.

Cannabis can cause forgetfulness, troubles focusing, hallucinations, and confusion. It can hurt the respiratory system- the lungs, vocal chords, throat, nose, mouth, and airways- and may trigger mental health problems.
Alcohol can damage the heart, liver, and pancreas over time. It makes it harder to think clearly, focus, and may weaken the immune system.
Nicotine is a chemical in cigarettes and vape juice. Not only can it cause problems with sleep, skin, and heart rate, but it can change how the brain deals with stress and learning. This can lead to addiction and withdrawal symptoms when not smoking.
I listed out some popular drugs here. If you want to know about the effects of other substances, try Google searching ‘symptoms of… [drug].’Depending on where you live, there are hotlines that deal with addictions and can connect you with a specialist in addiction medicine. All it takes is a quick Google search to find the number based on your location. Try looking up “hotline for substance addiction in [where you live].”
If you or someone you know is struggling with drug addiction, please tell someone you trust who will help support you: a parent, teacher, friend, or coach.

Thank you for reading and supporting this post- stay safe and have a great month!