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Illicit drug use

10-minute read

Key facts

  • Illicit drug use (drug abuse) is when a drug is used for a different purpose than intended.
  • It can involve illegal drugs as well as medicines.
  • Illicit drug use can lead to drug tolerance, dependence and addiction.
  • These problems can impact your mental and physical health, relationships, jobs and education.
  • You can overcome drug abuse with support and treatment — it’s important to speak with your doctor.

What is illicit drug use?

When a drug is not used as intended, it’s known as an illicit drug.

Illicit drug use, also known as drug abuse, is when a drug is used in an inappropriate or harmful way. This can mean it’s used for a different purpose or taken in excessive amounts.

Illicit drugs include illegal drugs, such as:

Illicit drugs can also include pharmaceuticals, such as over-the-counter and prescription medicines.

More than 4 in 10 Australians aged over 14 years have used an illicit drug.

The non-medical use of pharmaceutical drugs is an ongoing public health problem in Australia.

Illicit drugs and the law

People who use illicit drugs can also get into legal trouble. Australia has laws about:

  • the use of drugs
  • the production of drugs
  • possessing and selling drugs
  • driving while under the influence of drugs

Breaking these laws can lead to penalties such as:

  • fines
  • being disqualified from driving
  • serving jail time

What are the complications of illicit drug use?

Drug use carries many risks, such as:

Often, you do not know how strong the drug is, or if other substances have been added to the batch. Even pills that look the same may have different ingredients and effects.

Pill testing can find out how strong a drug is, or if other substances have been added to the batch. These services are becoming available in parts of Australia. You might see a pill testing service at a music festival.

Drug tolerance

If you regularly use a drug you can develop a tolerance. This means that you need to take larger doses of the drug to feel the same effect.

Depending on how often you take a drug, your tolerance can change. This puts you at a higher chance of an overdose, which can be fatal (cause death).

Drug dependence

A long-term consequence of illicit drug or medication use is drug dependence.

Drug dependence is when you have a physical need for a drug to function normally. You may not be able to reduce or stop using the drug.

When you try to stop taking the drug, you may have withdrawal symptoms. These can include:

  • cravings for the drug
  • exhaustion
  • changes in your mood

Drug dependence can make it physically hard to stop taking a drug.

Drug addiction

Regular use of a drug can lead to drug addiction or substance use disorder.

Addiction is not being able to control or stop using a drug, even though it’s causing harm. Drug addiction can have a negative impact on your life, and those around you.

You may have a drug addiction if you take a drug, and you:

  • rely on the drug to cope emotionally, socially or physically
  • take part in dangerous activities due to drug use, such as drug driving
  • lie about how much drug you are using

If you have a drug addiction you may find that you:

  • withdraw yourself from your family and friends
  • have problems with your relationships, school or work
  • have financial problems because of the cost of buying drugs
  • feel anxious, angry or depressed

What can lead to harm from illicit drug use?

Some things may place you at a higher chance of harm from illicit drug use, such as if you:

  • have a mental health issue
  • are a young person aged 14 to 29 years
  • have a family member who has had problems with illicit drug use

Different people react to drugs differently. Your chance of drug dependence and addiction can be related to your:

  • genetics
  • home environment
  • school and social environment

How is illicit drug use diagnosed?

Illicit drugs can be found by:

Drug dependence and addiction can be diagnosed by a doctor or a mental health professional.

When should I see my doctor?

The first step to overcoming drug abuse is recognising that there is a problem.

You should speak with your doctor if:

  • you would like to stop using drugs
  • if your drug use impacts your physical or mental health
  • if your drug use impacts your life and daily functioning

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

When to seek urgent care

If you suspect you or someone else is having a drug overdose, call triple zero (000) for an ambulance.

You are at risk of an overdose if you:

  • take too much of a drug
  • take a drug that is very strong
  • take different types of drugs together

Overdosing on different drugs causes different symptoms.

A person who has overdosed on a stimulant such as ice or codeine may:

A person who has overdosed on an opioid such as heroin or codeine may be unresponsive or have trouble breathing.

Naloxone is a medicine that can temporarily reverse the effects of an opioid overdose. The Australian Government is offering this medication free of charge and without a prescription to people who may experience, or witness, an opioid overdose.

Learn more about the Take Home Naloxone program.

How is illicit drug use treated?

You can recover from drug abuse. Your doctor can advise you on treatment options, such as:

Your doctor can:

  • help you overcome illicit drug use
  • help prevent you from having a relapse
  • help you manage withdrawal symptoms
  • refer you to further help, such as to an addiction specialist

Self-care at home

If you are struggling with illicit drug use, it’s important to get support, from:

  • family members
  • friends
  • teachers or colleagues

If you’re concerned about someone you know, find out how you can help them with their drug problem.

Medicines for illicit drug use

Rehabilitation from drug abuse can include medicines, such as methadone for recovering heroin users.

Can the complications of illicit drug use be prevented?

You can help prevent harm from illicit drug use by:

  • building strong relationships with your family and friends
  • spending time with people or in communities who have lower levels of drug use
  • seeking support and advice from your doctor

Resources and support

If you need to talk to someone about drug use, addiction and rehabilitation, you can:

Other languages

If you speak a language other than English, you can watch the ‘Where can I get help when alcohol or drugs are a problem?’ video from Health Translations.

Aboriginal and/or Torres Strait Islander peoples

If you are an Aboriginal and/or Torres Strait Islander person, you may want to visit:

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: January 2025


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