Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Marijuana and mental health

3-minute read

Marijuana is one of the most commonly used illicit drugs in Australia. It can make you feel chilled, but it also causes dependence, memory problems, paranoia and psychosis.

Marijuana is made from the dried leaves and flowers of a plant called Cannabis sativa. It’s also called dope, pot, grass, spliff, weed and joint. It’s usually smoked through a joint (like a cigarette) or through a bong or water pipe.

It’s illegal to use, possess, grow or sell cannabis in Australia. The penalties are different in each state.

Marijuana effects

Marijuana affects everyone differently. It can make you feel relaxed and happy, or quiet and reflective. The effects are felt soon after smoking it. But marijuana can also have harmful physical effects. Find out more about so called party drugs, including where to find help and support.

Mental health issues

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

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

People who use marijuana have been shown to have higher levels of depression and depressive symptoms than those who do not use it. It can also lead to temporary symptoms of anxiety such as panic.

Learn more about how marijuana affects mental health.

Marijuana can cause:

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.

People who use marijuana are more likely to have social and financial problems, do poorly at school, and have family and relationship issues. Learn more about the impact of illegal drug use.

Marijuana is particularly risky for people who have mental illness in the family.

Kicking the habit

People who use marijuana repeatedly for long periods can become dependent on it. If they stop using, they might feel anxious, irritable and angry, not feel like eating and have trouble sleeping.

Not sure what to do next?

If you or someone you know are finding it difficult to manage mental health 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).

Last reviewed: September 2017

Need more information?

These trusted information partners have more on this topic.

Top results

Cannabis use -

Cannabis can affect your physical and mental health with heavy cannabis use potentially causing psychosis.

Read more on myDr website

Am I at risk of developing psychosis? - OnTrack

OnTrack offers online psychology services such as free online treatment programs, information and facts about mental and physical health, information and advice on where to get help and access to quizzes with immediate feedback.

Read more on OnTrack website

Cannabis/marijuana: what are the effects? -

The effect of cannabis on a person depends on many factors including their size, weight and health and the amount taken.

Read more on myDr website

ADF - Drug Facts - Synthetic Cannabis

Synthetic cannabis is a new psychoactive substance that was originally designed to mimic or produce similar effects to cannabis

Read more on Alcohol and Drug Foundation website

Understanding cannabis for young people

Read more on headspace website

Mental Health Checklist TINO : Tune In Not Out

You are worried

Read more on Tune In Not Out website


Lifeline is a trusted national charity that has been saving lives for more 50 years. Lifeline works to prevent suicide through a range of crisis support services including its national telephone crisis support line, 13 11 14, operating 24/7 and Online Crisis Support Chat that is available every night.

Read more on Lifeline website

Sleep fact sheet

Sleep is a really important part of our life. It helps us to feel well, focused and happy. Most people experience a bad night's sleep now and again, but if you regularly don't get enough sleep it can really affect how you feel and what you can get done during the day.

Read more on headspace website

Social, Emotional and Cultural Wellbeing - Alcohol and Other Drugs Knowledge Centre

Read more on Australian Indigenous HealthInfoNet website

ADF - Drug Facts - Cannabis, Weed, Marijuana

Cannabis is a depressant drug, which means it slows down messages travelling between your brain and body. The main active chemical in cannabis is THC

Read more on Alcohol and Drug Foundation website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Government of Western Australia, health department logo