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Drugs: The facts

What is a drug?

What are the laws about drugs?

Drug use in Australia

How could drugs affect you?

Tolerance and dependence

Getting help

Preventing and reducing harms

Need information on a particular drug? Browse drug facts.

What is a drug?

A drug is a substance, other than food, which is taken to change the way the body and/or mind function.

Mood altering drugs are also called 'psychoactive drugs'. They can affect the way a person thinks, feels and acts. These drugs usually have physical effects as well, but what sets them apart from other drugs is that they work on the mind and the senses.

What are the laws about drugs?

Legal drugs

Some drugs, such as alcohol, caffeine, nicotine and various prescribed and over-the-counter medications, are legal.

Although these drugs are legal, there are laws that restrict their availability, quality and price.

Illegal drugs

Other drugs such as cannabis, amphetamines, ecstasy, cocaine and heroin, are illegal. This means they cannot be subject to quality or price controls. A person using illegal drugs can never be sure of how strong the drug is, or what is actually in it.

Different batches of an illegally manufactured drug may have different amounts of the drug and other unidentified additives.

Federal and state laws provide penalties for possessing, using, making, selling or driving under the influence of illicit drugs. Penalties can include fines, imprisonment and disqualification from driving.

Some states and territories have programs that refer people with a drug problem to treatment and/or education programs where they can receive help rather than going through the criminal justice system.

Read more about drugs and the law.

Drug use in Australia

How many people use drugs?

Find statistics on drug use in Australia.

Why do people use drugs?

People use drugs to relax, to function, for enjoyment, to be part of a group, out of curiosity or to avoid physical and/or psychological pain.

Drug use is influenced by a number of factors. Most people use drugs because they want to feel better or different. They use drugs for the benefits (perceived and/or experienced), not for the potential harm. This applies to both legal and illegal drugs.

Types of drug use 

These are some of the different categories of drug use. People can move between the categories, and one stage will not inevitably lead to another.

Experimental use: a person tries a drug once or twice out of curiosity.

Recreational use: a person chooses to use a drug for enjoyment, particularly to enhance a mood or social occasion.

Situational use: a drug is used to cope with the demands of particular situations.

Intensive use or 'bingeing': a person consumes a heavy amount of drugs over a short period of time, and/or uses continuously over a number of days or weeks.

Dependent use: a person becomes dependent on a drug after prolonged or heavy use over time. They feel a need to take the drug consistently in order to feel normal or to avoid uncomfortable withdrawal symptoms.

How could drugs affect you?

The effects of any drug vary from person to person. How a drug affects a person can depend on their size, weight and health, also whether the person is used to taking the drug, and whether other drugs are in their system at the same time.

The effects will also depend on the amount taken. It can be hard to judge how much of an illegal drug has been taken, as they are uncontrolled, so quality and strength will vary from one batch to another.


These include alcohol, benzodiazepines (minor tranquillisers), cannabis, GHB, heroin, morphine, codeine, methadone, and some inhalants.

Depressants do not necessarily make a person feel depressed. They affect the central nervous system, slowing down the messages between the brain and the body.

They can affect concentration and coordination. They slow down the person's ability to respond to unexpected situations. In small doses they can cause a person to feel more relaxed and less inhibited. In larger doses they can cause drowsiness, vomiting, unconsciousness and death.


These include caffeine, ephedrine, nicotine, amphetamines, cocaine and ecstasy (MDMA).

Stimulant drugs speed up the messages between the brain and the body. The can make a person feel more awake, alert, confident or energetic.

Large doses of stimulants can cause over-stimulation, causing anxiety, panic, seizures, headaches, stomach cramps, aggression and paranoia. Long-term use of strong stimulants can also cause these effects.


These include ketamine, LSD, datura, magic mushrooms (psilobycin) and mescaline (peyote cactus). Cannabis and ecstasy can also have hallucinogenic qualities.

Hallucinogens distort a person's perception of reality. People who have taken them may imagine they see or hear things, or what they see may be distorted. The effects of different hallucinogens vary.

There is no safe level of drug use. Use of any drug always carries some risk—even medications can produce unwanted side effects. It is important to be careful when taking any type of drug.

Other effects of drug use

Pregnancy and breastfeeding

Many drugs can cross the placenta and affect the unborn child.

Read more about the effects of drugs on pregnancy and breastfeeding.

Drugs and driving

It is dangerous to drive after taking drugs. The effects of drugs can affect driving ability, increasing the chance of an accident.

Symptoms of withdrawal and 'coming down' after drug use can also affect driving ability.

Read more about the effects of drugs on safe driving

Drugs and the workplace

Under occupational health and safety legislation, all employees have a responsibility to make sure they look after their own and their co-workers' safety.

The effects of drugs, and the symptoms of coming down and withdrawal, can affect a person's ability to work safely and effectively.

Find out about the Australian Drug Foundation's Good Hosts program, assisting organisations to manage alcohol-related risk in the workplace.

Read about the risks and responsibilities involved with alcohol in the workplace.

Tolerance and dependence

There is evidence that after prolonged use, many drugs can cause dependence. People who use a drug regularly can develop dependence and tolerance to it. This means they need to take larger amounts of the drug to get the same effect.

Dependence on a drug can be psychological, physical, or both. People who are dependent on the drug find that using the drug becomes far more important than other activities in their life. They crave the drug and find it very difficult to stop using it.

People who are psychologically dependent on a drug may find they feel the urge to use it when they are in specific surroundings, such as socialising with friends.

Physical dependence occurs when a person's body adapts to a drug and gets used to functioning with the drug present.

Getting help

In Australia, there are many different treatment options for drug problems. Some aim to help a person stop using a drug, while others aim to reduce the risks and harm related to their drug use.

Read more about treatment.


If a dependent person stops taking a drug, they may have withdrawal symptoms and cravings while their body gets used to functioning without the drug.

Note: Seek medical advice for withdrawal from alcohol or benzodiazepines, as it may cause seizures.

Read more about withdrawal.

What to do if you are concerned about someone’s drug use

If you are concerned about someone’s drug use, there is help available. Contact the alcohol and drug information service in your state or territory.

What to do in a crisis

Always call triple zero (000) if a drug overdose is known or suspected and remember that paramedics are not obliged to involve the police. 

If someone overdoses or has an adverse reaction while using GHB, it is very important that they receive professional help as soon as possible. A quick response can save their life.

Visit the Better Health Channel to read St John Ambulance's advice on drug overdose.

Preventing and reducing harms

Many Australians take at least one psychoactive drug on a regular basis—they might take medication (i.e. over-the-counter or via a prescription), drink alcohol, smoke tobacco or use an illegal drug. All drugs have the potential to cause harm. As use increases, so does the potential for harm.

Australia’s national drug policy is based on harm minimisation. Strategies to minimise harm include encouraging people to avoid using a drug, through to helping people to reduce the risk of harm if they do use a drug. It aims to reduce all types of drug-related harm to both the individual and the community.

Educational resources on drugs

Free resources on drugs

Search the ADF Shop.


This information has been adapted from the pamphlet Drugs and their effects, produced by the Australian Drug Foundation. For single copies of this pamphlet, contact DrugInfo (Victoria only). Multiple copies are available from the ADF Bookshop.

Last updated:  27 June 2014

Information you heard is intended as a general guide only. This audio is copyrighted by the Australian Drug Foundation. Visit for more