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Teen Health Info

Alcohol and other drugs – what you need to know

  • At a glance

    • A drug is any chemical or substance that changes how your body works. This includes prescription medicines, caffeine, alcohol, tobacco and illegal drugs.
    • When you are young, drinking alcohol can change the way your brain develops.
    • Drinking alcohol isn’t legal or recommended for people under age 18.
    • Drugs can affect your mood, energy, thinking, sense of reality and how you move your body.
    • If you are worried that you, or someone you know, might be addicted to alcohol or drugs, there are many places to get help.
    • In a drug or alcohol emergency, such as a drug overdose, call an ambulance (000) immediately.

    Read the parent fact sheet

    Alcohol

    What is alcohol?

    When people talk about ‘alcohol,’ they are usually referring to alcoholic drinks, such as beer, wine, or spirits like vodka. These drinks have a chemical in them called ethanol that affects the brain. Every alcoholic drink has different amounts of ethanol; that’s why some are stronger than others. More ethanol means a stronger drink.

    Harm from alcohol is linked to how much you drink: the less you drink, the lower your risk.

    In Australia, it’s not legal or recommended to drink alcohol under the age of 18.

    What does alcohol do to the body?

    The ethanol in alcoholic drinks is a 'depressant.’ This means it slows down your brain activity and the messages sent between your brain and body.

    • In small amounts, alcohol can make you feel relaxed and more comfortable acting without thinking first.
    • In larger amounts, alcohol can make you sleepy, slower to respond and affect how you move your body (coordination).
    • In very large amounts, alcohol is dangerous for the body. The ethanol can be toxic and cause alcohol poisoning, leading to vomiting, passing out (losing consciousness) and even death.

    Is alcohol bad for teens?

    Your brain is still forming as a teen. Research shows that regular, heavy alcohol drinking can cause changes in your brain. These changes might make it harder for you to:

    • learn in class
    • make good decisions
    • remember information
    • pay attention
    • have healthy relationships with friends and family
    • sleep properly.

    Some longer-term effects of drinking lots of alcohol are:

    • Organ damage (especially the liver, brain and heart)
    • Higher risk of several types of cancer
    • Ongoing mental health problems like depression.

    You are also more likely to develop a lifelong addiction to alcohol if you drink it at a younger age.

    Binge drinking

    If you drink alcohol as a teen, you are more likely to drink lots in one night. This is called ‘binge drinking.’ Binge drinking is having four or more standard drinks for women, or five or more standard drinks for men, within two hours.

    Binge drinking is linked to mental health challenges, taking risks, car accidents and using other drugs. Research shows that binge drinking can be as bad as drinking every day.

    If you binge drink, you might get side effects like:

    • feeling sick (nausea) and/or vomiting
    • headaches
    • shaking and dehydration
    • dizziness
    • muscle aches or weakness
    • feeling anxious, depressed or irritated.

    Drugs

    What is a drug?

    A drug is any chemical or substance that changes how your body works. The word ’drugs’ is often used to talk about illegal or recreational (taken at parties or ‘for fun’) substances. But medicines that treat pain or sickness are also drugs.

    The most common types of drugs are:

    • Over-the-counter medicines, like paracetamol
    • Prescription medicines used for medical reasons, like antibiotics to treat infections
    • Prescription medicines used for non-medical reasons, like taking strong pain medicine when you aren't in pain
    • Substances like caffeine (in coffee or energy drinks), alcohol and nicotine (in cigarettes and vapes)
    • Illegal drugs like weed (marijuana), cocaine and ecstasy.

    Some drugs are taken by mouth, like tablets or liquids. Others are breathed in (inhaled) or injected using a needle.

    What do drugs do to the body?

    After you take drugs, they get into your bloodstream and impact different parts of your body. Most drug effects happen when they reach your brain.

    In the brain, drugs can change:

    • your mood (making you feel happier, calmer or sadder)
    • your energy (giving you lots of energy or making you sleepy)
    • how you think
    • how well you can move, walk and talk
    • your sense of reality (perception). For example, you might see different colours or things that aren’t there.

    Some drugs have effects when they wear off. For example, you might feel depressed or very tired the day after taking them. This is called a 'come down.'

    Different types of drugs

    The three most common groups of drugs are:

    • Depressants (slow down brain activity). For example, alcohol, ketamine and opioids (like heroin).
    • Hallucinogens (change your sense of reality). For example, magic mushrooms (psilocybin) and LSD (lysergic acid diethylamide).
    • Stimulants (speed up brain activity). For example, caffeine, nicotine and ecstasy.

    Some drugs fall into more than one group. Weed (marijuana), for example, is a depressant and a hallucinogen.

    Illegal drugs don’t have to follow the same rules as the legal ones you get at supermarkets and pharmacies. So, it’s impossible to know what you are buying or how much of a drug you are taking. People might also mix (or ‘cut’) drugs with other substances to create more ‘product’ and increase the money they get from them. This makes it easier to accidentally take too much or take something you didn’t want.

    Prescription drugs

    Some people misuse legal drugs that doctors prescribe (prescription medicines).

    This could mean taking:

    • more medicine than what a doctor prescribed
    • medicine more often than a doctor prescribed
    • someone else’s medicine.

    Prescription drugs that people might misuse include:

    • Pain medicines like oxycodone (or ‘oxy’)
    • Anti-anxiety medicines called benzodiazepines (or 'benzos'), like diazepam
    • Medicines for attention deficit hyperactivity disorder (ADHD), like dexamphetamine (or 'dexies').

    What are the risks of taking drugs?

    Every drug affects the body differently, but many have the same risks.

    • Some drugs can be dangerous – especially if you take too much (overdose). They can make you very sick, affect your heart or breathing, and even cause death.
    • Just like alcohol, drugs can affect your brain if you take them as a teen. Parts of your brain that control memory and decision-making might not form properly.
    • Most drugs can change your behaviour in some way. For example, they might make you feel angry or change your thinking so you can’t make safe and logical decisions. This behaviour might affect your relationships with family and friends.
    • Drugs can be addictive. When you take them, they might make you feel good and cause chemical changes in your brain, so you want more. Over time, your body gets used to having these drugs, and it gets harder to live without them.
    • Some drugs have many names. For example, LSD is also called 'acid.' This can make it hard to know what you are taking.
    • Spending lots of time taking drugs can have flow-on effects on other parts of your life. For example, you might not be able to finish your schoolwork, save any money, or connect with your family and friends.

    How do I know if I have a drug or alcohol addiction?

    Alcohol and drug addiction is also known as 'dependence.' It can include physical and emotional symptoms.

    You might have an addiction if you:

    • spend a lot of time thinking about the substance
    • need to take the substance soon after waking up each day
    • feel like you should cut down on your substance use
    • find that your substance use is impacting your usual activities like school, work, sport, relationships, or your health
    • feel guilty or bad about your substance use
    • get physical side effects (withdrawal) like feeling shaky, jumpy, irritated or sick if you don't take the substance.

    Where to get help for drug and alcohol use

    In a drug or alcohol emergency, call an ambulance (000) immediately. Paramedics and doctors can treat you for free; they don't need your parents’ permission. For less urgent help, you could:

    • speak to a trusted adult – whether that’s a parent, teacher or someone else you are comfortable with.
    • see your local doctor (general practitioner, or ‘GP’). They might suggest an alcohol and drug service for young people, or a mental health worker with extra training in addiction.
    • contact the National Alcohol and Other Drug Hotline (open 24/7) or get in touch with headspace for information and counselling (in-person or online). In Victoria, you could also connect with the Youth Drug and Alcohol Service (YoDAA).

    Things you might be wondering

    What is a standard drink?

    In Australia, a standard drink always contains 10g (grams) of pure alcohol. What changes between drinks is the alcohol content. For example, one standard drink is around 100mL of red wine (13.5% alcohol) but only 30mL of spirits (40% alcohol).

    Why do people drink or take drugs?

    There are lots of reasons why people might drink alcohol or take drugs. These substances make some people more relaxed, happier, comfortable, or less nervous in social settings. Sometimes people drink or take drugs to experiment or try to fit in with friends. This might be okay if you are old enough (over 18 years), you want to do it, and you feel safe. But people should never pressure you into drinking or taking drugs. In Australia, it's not legal for people under 18 years old to drink alcohol, vape or smoke, or for anyone to use illegal drugs.

    Are all drugs bad?

    As over-the-counter medicines like paracetamol are types of drugs, it's not correct to say all drugs are bad. Many drugs can help the body, such as reducing pain or healing infections.

    How does the government decide which drugs are illegal?

    The government of each country decides which drugs are illegal. Most drugs are illegal because they don't have medical benefits, or they are addictive, harmful and/or dangerous – especially if you take too much.

    Are legal drugs safe?

    Drugs aren't safe just because they are legal. In most cases, a drug's safety depends on the amount you take. For example, you can get very sick from taking too much paracetamol, even though you can buy it from the supermarket. Whether you take over-the-counter or prescription medicine, you should always follow the directions for use.

    How do I say no to drugs or alcohol at a party?

    Sometimes it can be hard to say no if everyone else is using drugs or drinking alcohol. You might feel embarrassed, left out or worried about what your friends will think. But you have a right to feel safe and make your own choices. Be confident and use words that make it about you, not anyone else. For example, a simple ‘No thanks’ or ‘I prefer not to’ is enough. You don't need an excuse, but if you feel more comfortable giving one, you could say you have work or sports training the next day, so you don't want a hangover.

    If someone keeps asking you to drink or take drugs, say no again, confirm your decision and ask them to respect your choice. It might be best to leave the party or spend time with other friends if you are being pressured or feel unsafe.

    How can I stay safe when drinking alcohol?

    There are a few ways to reduce your risk if you decide to drink alcohol. Make sure you stay around people you trust or have someone you can contact if you feel unsafe. Always try to plan how you will get home before you go out at night.

    You should always avoid mixing alcohol with other drugs. If you take prescription medicines, check if it's safe to drink alcohol while on them. Remember to drink water so you don't get dehydrated, and eat regularly – especially if you are out for a long time.

    I am worried my friend is addicted to drugs. How can I help them?

    Start by talking to your friend about their drug use. You could share things you have noticed and offer to help them get support. The alcohol safety advice above will also help keep your friend safe, like suggesting they stay with people they trust, drink water and don't mix drugs.

    If you think your friend is in trouble but they don't agree to get help, speak to a trusted adult or get advice from a phone or online counselling service. Always call an ambulance (000) immediately in a drug or alcohol emergency.

    Is it true that most teens drink alcohol and take drugs?

    Most teens in Australia are actually choosing not to drink or use other drugs. A recent Australia-wide survey of high school students showed that most teens said they had never smoked, vaped or used drugs. More than one in three teens surveyed said they had never drunk alcohol in their lifetime.

    Helpful links


    Developed by The Royal Children’s Hospital (RCH); medical review by the Adolescent Medicine department, with input from the Psychology department. Created with advice from the RCH Health Literacy Youth Advisory Committee.

    Reviewed August 2025

    Speak with a doctor for up-to-date and personalised medical advice.


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    Disclaimer

    This information is designed to help you have conversations with your doctor or health care professionals. It is not intended to replace personal medical advice. The authors of these fact sheets have worked hard to make sure the information is accurate, up-to-date and easy to understand. The Royal Children’s Hospital Melbourne does not accept responsibility for any content inaccuracies, information seen as misleading, or the success of any treatments explained in these fact sheets. Information in these fact sheets is updated regularly. If you download or print the fact sheet, the responsibility is on you, the user, to make sure you are reading the most up-to-date version.

    Updated July 2025

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