Cannabis and mental health

How cannabis can affect mental health and brain function.

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Risks to mental health

If you use cannabis socially, to relax, or to cope with poor mental health, it's important to understand the long-term risks. These are some of the ways daily or near daily cannabis use can affect your mental health.

Developing anxiety and depression

Daily or near daily cannabis use over time can increase your chances of developing disorders related to anxiety and depression. Long-term daily or near daily use can also negatively impact your brain's dopamine system, which gives you feelings of pleasure and joy. This can make you feel:

  • fatigued
  • low in mood
  • unmotivated

Worsening anxiety and depression

Some people use cannabis to provide relief from stress or from feeling anxious or depressed. However, cannabis use has not been found to improve mental health over time. Daily or near daily cannabis use actually contributes to poor mental health, and if you use cannabis this frequently you could:

  • become dependent on cannabis
  • have trouble regulating your emotions
  • experience anxiety and depression more often

You're more likely to recover from long-term anxiety and depression if you reduce or stop using cannabis.

Cannabis dependency

You can become dependent on cannabis over time, just like you can with other drugs, alcohol and tobacco. Symptoms can include:

  • craving cannabis
  • thinking a lot about cannabis
  • finding it hard to stop or reduce use
  • feeling like you need to use cannabis
  • an increased tolerance to cannabis
  • feeling increasingly restless, moody or anxious when not using cannabis

Psychosis and schizophrenia

Psychosis is a temporary mental state that can involve severe paranoia and hearing or seeing things that are not real. Schizophrenia is a longer-term form of psychosis that requires life-long treatment, and includes symptoms like:

  • paranoia
  • hallucinations
  • disordered thinking, speech and behaviour

In severe cases, daily or near daily cannabis use can increase your chance of experiencing psychosis and schizophrenia. These cases are more likely among people with a personal or family history of mental health disorders, particularly male teenagers and young adults.

Risks to brain function

Daily or near daily cannabis use can harm your short and long-term memory, thought patterns, focus and speech. You may:

  • have trouble remembering what you just thought or said
  • think unusual or abnormal thoughts
  • become distracted or have trouble concentrating
  • have trouble forming sentences or experience delayed speech

These effects can be frustrating and distressing, especially if it impacts your:

  • self-image
  • performance at work or school
  • relationships with family and friends

Reducing or stopping cannabis use can reverse some or all of its effects, and can help improve your long-term mental health and brain function. Everyone's response to cannabis and their response to reducing or stopping cannabis can differ. Seeking support from a loved one or a healthcare professional can help.

Lower your risk

Avoid daily or near daily use. The effects on your mental health and brain function over time are greatest if you use cannabis this frequently.

Delay using cannabis. Cannabis can interfere with brain development until around the age of 25. If you're an adolescent or a young adult, your mental health and brain function are at greater risk of harm.

Choose products with lower levels of THC. The higher the THC content of a product, the more likely you are to experience harms related to mental health and brain function. Any product with over 10% or 10mg of THC is considered high.

Avoid combining cannabis with alcohol or other substances. Using cannabis at the same time as alcohol or other substances further increases the risks to your mental health and brain function.

Avoid cannabis if you have a personal or family history of mental health disorders. You're at higher risk if you have a family history of:

  • psychosis
  • schizophrenia
  • substance dependence

Avoid inhalable products. You're more likely to use and become dependent on cannabis if you smoke or vape than if you use non-inhalable products like:

  • oils
  • edibles
  • capsules

Check in with yourself. Take some time to reflect on your cannabis use and evaluate your relationship with cannabis. Reducing or stopping daily or near-daily use can be difficult to do on your own. Talk to someone you trust if you need help, such as a:

  • friend
  • counsellor
  • family member
  • healthcare professional

Related links


For more information on how cannabis can affect mental health and brain function, consult the references below.

Mental health

Effects on anxiety and depression

Cannabis dependency

Psychosis and schizophrenia

Brain function

Effects of reducing or stopping cannabis use

Lowering risk

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