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Cannabis (marijuana)

7-minute read

What is cannabis?

Cannabis is the general name for drugs like marijuana, hash and hashish oil that are made from the plant cannabis sativa. It’s the most commonly used illicit drug in Australia.

The different forms of cannabis are:

  • marijuana: made from the plant's dried leaves and flowers, and the most common form of cannabis. It is smoked in a joint or bong
  • hashish: dried resin from the plant, usually mixed with tobacco and smoked or added to food, such as cookies or brownies
  • hash oil: a liquid added to the tip of a joint or cigarette
  • concentrates: cannabis extracts usually dissolved in butane hash oil

Cannabis is also known as marijuana, yarndi, pot, weed, hash, dope, gunja, joint, stick, chronic, cone, choof, mull, 420, dabs, dabbing or BHO.

In most states and territories in Australia, it is illegal to use, possess, cultivate or sell cannabis in Australia. However, in the ACT, the laws governing cannabis possession, cultivation and use have changed.

It is illegal to drive under the effects of cannabis — regardless of which state or territory you are in.

Medicinal cannabis

Medicinal cannabis continues to be researched and is increasingly used as a medication in several health conditions, including to manage chronic pain, reduce nausea and vomiting (caused by chemotherapy) and treat epilepsy. Its supply is tightly controlled in Australia. You can only access medicinal cannabis through a healthcare practitioner. See the Therapeutic Goods Administration website for more information.

Synthetic cannabis

There is also a new psychoactive substance called synthetic cannabis, which are chemicals mixed with solvents and added to herbs. The chemicals are supposed to mimic the effects of the active ingredient in cannabis (called delta-9 tetrahydrocannabinol, or THC). Not all forms of synthetic cannabis mimic THC and they may be more harmful than real cannabis.

Synthetic cannabis is marketed under names like Spice, Kronic, Northern Lights, Mojo, Lightning Gold, Blue Lotus and Godfather. Find out more about synthetic cannabis on the Alcohol and Drug Foundation website.

What are the effects of taking cannabis?

Cannabis is a central nervous system depressant, which means it slows down brain activity and produces feelings of relaxation and drowsiness. The effects are usually felt straight after is it smoked or vaporised, but they can be felt several hours after it is taken.

It can make people feel ‘chilled out’, relaxed, happy and sociable. People who take cannabis may laugh a lot, have heightened senses or feel hungry. They may also become drowsy.

It can also cause unwanted side effects, such as:

  • balance problems
  • rapid heart rate
  • red, dry eyes
  • dry mouth and throat
  • nausea
  • memory problems
  • slower reflexes
  • anxiety or paranoia

Cannabis can affect people differently based on:

  • how much they take
  • how strong it is
  • their size, height and weight
  • whether they are used to taking it
  • whether they take other drugs at the same time

Find out more about how drugs and alcohol can impact your health, including where to find help and support.

What can go wrong with cannabis?

People who have taken a lot of cannabis can become very unwell and their situation can become an emergency.

Someone who has taken lots of cannabis can become sick and vomit. They can also become drowsy. If they vomit while sleeping, they may suffocate. Do not leave someone in this condition alone.

Someone who has had lots of cannabis may also have an accident. They may experience hallucinations, panic attacks or paranoia — stay with them and help to keep them calm.

If their condition worsens or they experience a head or other serious injury, call 000.

Cannabis can trigger a psychotic disorder like schizophrenia in people who are already at risk of developing the disorder. In these people, using cannabis may mean they develop the problem earlier.

There is also some evidence that cannabis can produce psychotic symptoms in people with a family history of mental illness. It can also make psychotic symptoms worse and harder to treat if you already have a mental illness like schizophrenia.

Anyone who has an existing mental health issue or who has a close family member with depression, psychosis, bipolar disorder or anxiety should avoid cannabis, as they are at particularly high risk of mental health problems being caused by the drug.

Can cannabis cause long-term problems?

Regular users have been shown to have higher levels of depression and depressive symptoms than those who do not use it. They may have social and financial problems, and don’t do as well in education, and have family and relationship issues.

Problems are more common for people who start using marijuana at early age, and for people who use it regularly.

People who use marijuana over long periods can:

  • become dependent
  • lose their sex drive
  • have problems with their memory
  • have learning difficulties
  • have mood swings
  • become psychotic, if they have schizophrenia or are at risk of psychosis
  • think about suicide
  • can get chest infections and sore throats, asthma or bronchitis. Combining cannabis with tobacco increases the risk of cancer
  • have lower sperm count
  • have irregular periods

What if I use other drugs or alcohol together with cannabis?

Mixing cannabis with other drugs such as alcohol or prescription medications can make the effects of all the drugs stronger and more unpredictable. You are more likely to become nauseous or vomit if you mix cannabis with alcohol.

Can I become dependent on cannabis?

Anyone can become dependent on cannabis. That means it takes up a lot of time and energy, and it is hard to stop.

People who use cannabis regularly may experience withdrawal symptoms including cravings, problems sleeping, mood swings, depression or anxiety, restlessness, reduced appetite or nausea. These problems are at their worst 2 to 4 days after quitting and usually last about 2 weeks.

Resources and support

Find out more about cannabis on the Alcohol and Drug Foundation website or by calling DrugInfo on 1300 85 85 84.

You can find help on the Drug Help website or by calling the National Alcohol and Other Drug Hotline on 1800 250 015. You can also call Lifeline on 13 11 14.

If you or someone you know are finding it difficult to manage issues as a result of drug use, try healthdirect’s Symptom Checker and get advice on when to seek professional help.

The Symptom Checker guides you to the next appropriate healthcare steps, whether it’s self care, talking to a health professional, going to a hospital or calling triple zero (000).

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

Last reviewed: March 2022

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